#### [PromptPlus](PromptPlus.md 'PromptPlus') ### [PromptPlusLibrary](PromptPlusLibrary.md 'PromptPlusLibrary') ## ITreeMultiSelectControl\ Interface Provides a fluent API for configuring and running a generic multi\-selection tree control that browses an arbitrary hierarchy of items of type [T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T') as an expandable/collapsible tree with tri\-state checkboxes \(unchecked / checked / indeterminate\)\. ```csharp public interface ITreeMultiSelectControl ``` #### Type parameters `T` The type of items in the tree\. ### Remarks The tree structure is built the same way as [ITreeSelectControl<T>](ITreeSelectControl_T_.md 'PromptPlusLibrary\.ITreeSelectControl\'): via [Root\(T, bool, bool\)](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.Root(T,bool,bool) 'PromptPlusLibrary\.ITreeMultiSelectControl\\.Root\(T, bool, bool\)'), [AddLast\(T, bool, bool\)](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.AddLast(T,bool,bool) 'PromptPlusLibrary\.ITreeMultiSelectControl\\.AddLast\(T, bool, bool\)')/ [AddFirst\(T, bool, bool\)](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.AddFirst(T,bool,bool) 'PromptPlusLibrary\.ITreeMultiSelectControl\\.AddFirst\(T, bool, bool\)'), [AddAfter\(ITreeNode<T>, T, bool, bool\)](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.AddAfter(PromptPlusLibrary.ITreeNode_T_,T,bool,bool) 'PromptPlusLibrary\.ITreeMultiSelectControl\\.AddAfter\(PromptPlusLibrary\.ITreeNode\, T, bool, bool\)')/ [AddBefore\(ITreeNode<T>, T, bool, bool\)](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.AddBefore(PromptPlusLibrary.ITreeNode_T_,T,bool,bool) 'PromptPlusLibrary\.ITreeMultiSelectControl\\.AddBefore\(PromptPlusLibrary\.ITreeNode\, T, bool, bool\)') and the [ITreeMultiSelectNode<T>](ITreeMultiSelectNode_T_.md 'PromptPlusLibrary\.ITreeMultiSelectNode\') children helpers\. Container nodes display a tri\-state checkbox that reflects the aggregate check state of their descendants\. Pressing the check key \(Space\) on a container cycles through Unchecked → Checked \(all descendants\) → Unchecked\. Pressing Enter confirms the selection and returns all checked leaf \(or all checked\) values\. Nodes can be marked `disable` at creation time: they are shown and navigable but cannot be checked/unchecked interactively; a cascading check still passes through a disabled node to reach its enabled descendants, and a disabled node force\-marked via [Default\(IEnumerable<T>, bool\)](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.Default(System.Collections.Generic.IEnumerable_T_,bool) 'PromptPlusLibrary\.ITreeMultiSelectControl\\.Default\(System\.Collections\.Generic\.IEnumerable\, bool\)') survives a mass\-uncheck \(`F2`\) unaffected, same as [IMultiSelectControl<T>](IMultiSelectControl_T_.md 'PromptPlusLibrary\.IMultiSelectControl\')\. Nodes can also be marked `check` at creation time to start pre\-checked \(additive with [Default\(IEnumerable<T>, bool\)](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.Default(System.Collections.Generic.IEnumerable_T_,bool) 'PromptPlusLibrary\.ITreeMultiSelectControl\\.Default\(System\.Collections\.Generic\.IEnumerable\, bool\)')/history — whichever marks a node checked, it stays checked\)\. [AddLast\(T, bool, bool\)](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.AddLast(T,bool,bool) 'PromptPlusLibrary\.ITreeMultiSelectControl\\.AddLast\(T, bool, bool\)')/ [AddFirst\(T, bool, bool\)](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.AddFirst(T,bool,bool) 'PromptPlusLibrary\.ITreeMultiSelectControl\\.AddFirst\(T, bool, bool\)')/[AddAfter\(ITreeNode<T>, T, bool, bool\)](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.AddAfter(PromptPlusLibrary.ITreeNode_T_,T,bool,bool) 'PromptPlusLibrary\.ITreeMultiSelectControl\\.AddAfter\(PromptPlusLibrary\.ITreeNode\, T, bool, bool\)')/ [AddBefore\(ITreeNode<T>, T, bool, bool\)](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.AddBefore(PromptPlusLibrary.ITreeNode_T_,T,bool,bool) 'PromptPlusLibrary\.ITreeMultiSelectControl\\.AddBefore\(PromptPlusLibrary\.ITreeNode\, T, bool, bool\)') return [ITreeMultiSelectNode<T>](ITreeMultiSelectNode_T_.md 'PromptPlusLibrary\.ITreeMultiSelectNode\') \(not the plain [ITreeNode<T>](ITreeNode_T_.md 'PromptPlusLibrary\.ITreeNode\')\), so chaining further down the tree keeps access to `check`, not just the top\-level calls made directly off the control\. ### Methods ## ITreeMultiSelectControl\\.AddAfter\(ITreeNode\, T, bool, bool\) Method Inserts a new sibling immediately after [node](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.AddAfter(PromptPlusLibrary.ITreeNode_T_,T,bool,bool).node 'PromptPlusLibrary\.ITreeMultiSelectControl\\.AddAfter\(PromptPlusLibrary\.ITreeNode\, T, bool, bool\)\.node')\. ```csharp PromptPlusLibrary.ITreeMultiSelectNode AddAfter(PromptPlusLibrary.ITreeNode node, T value, bool disable=false, bool check=false); ``` #### Parameters `node` [PromptPlusLibrary\.ITreeNode<](ITreeNode_T_.md 'PromptPlusLibrary\.ITreeNode\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeNode_T_.md 'PromptPlusLibrary\.ITreeNode\') The reference sibling\. Cannot be `null`\. `value` [T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T') The value of the new node\. Cannot be `null`\. `disable` [System\.Boolean](https://learn.microsoft.com/en-us/dotnet/api/system.boolean 'System\.Boolean') When `true`, the new node cannot be checked\. Default is `false`\. `check` [System\.Boolean](https://learn.microsoft.com/en-us/dotnet/api/system.boolean 'System\.Boolean') Same semantics as in [Root\(T, bool, bool\)](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.Root(T,bool,bool) 'PromptPlusLibrary\.ITreeMultiSelectControl\\.Root\(T, bool, bool\)')\. #### Returns [PromptPlusLibrary\.ITreeMultiSelectNode<](ITreeMultiSelectNode_T_.md 'PromptPlusLibrary\.ITreeMultiSelectNode\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectNode_T_.md 'PromptPlusLibrary\.ITreeMultiSelectNode\') #### Exceptions [System\.InvalidOperationException](https://learn.microsoft.com/en-us/dotnet/api/system.invalidoperationexception 'System\.InvalidOperationException') Thrown if [node](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.AddAfter(PromptPlusLibrary.ITreeNode_T_,T,bool,bool).node 'PromptPlusLibrary\.ITreeMultiSelectControl\\.AddAfter\(PromptPlusLibrary\.ITreeNode\, T, bool, bool\)\.node') does not belong to this tree or is the root\. ## ITreeMultiSelectControl\\.AddBefore\(ITreeNode\, T, bool, bool\) Method Inserts a new sibling immediately before [node](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.AddBefore(PromptPlusLibrary.ITreeNode_T_,T,bool,bool).node 'PromptPlusLibrary\.ITreeMultiSelectControl\\.AddBefore\(PromptPlusLibrary\.ITreeNode\, T, bool, bool\)\.node')\. ```csharp PromptPlusLibrary.ITreeMultiSelectNode AddBefore(PromptPlusLibrary.ITreeNode node, T value, bool disable=false, bool check=false); ``` #### Parameters `node` [PromptPlusLibrary\.ITreeNode<](ITreeNode_T_.md 'PromptPlusLibrary\.ITreeNode\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeNode_T_.md 'PromptPlusLibrary\.ITreeNode\') The reference sibling\. Cannot be `null`\. `value` [T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T') The value of the new node\. Cannot be `null`\. `disable` [System\.Boolean](https://learn.microsoft.com/en-us/dotnet/api/system.boolean 'System\.Boolean') When `true`, the new node cannot be checked\. Default is `false`\. `check` [System\.Boolean](https://learn.microsoft.com/en-us/dotnet/api/system.boolean 'System\.Boolean') Same semantics as in [Root\(T, bool, bool\)](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.Root(T,bool,bool) 'PromptPlusLibrary\.ITreeMultiSelectControl\\.Root\(T, bool, bool\)')\. #### Returns [PromptPlusLibrary\.ITreeMultiSelectNode<](ITreeMultiSelectNode_T_.md 'PromptPlusLibrary\.ITreeMultiSelectNode\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectNode_T_.md 'PromptPlusLibrary\.ITreeMultiSelectNode\') #### Exceptions [System\.InvalidOperationException](https://learn.microsoft.com/en-us/dotnet/api/system.invalidoperationexception 'System\.InvalidOperationException') Thrown if [node](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.AddBefore(PromptPlusLibrary.ITreeNode_T_,T,bool,bool).node 'PromptPlusLibrary\.ITreeMultiSelectControl\\.AddBefore\(PromptPlusLibrary\.ITreeNode\, T, bool, bool\)\.node') does not belong to this tree or is the root\. ## ITreeMultiSelectControl\\.AddFirst\(T, bool, bool\) Method Adds a new node as the first child of the root and returns it\. ```csharp PromptPlusLibrary.ITreeMultiSelectNode AddFirst(T value, bool disable=false, bool check=false); ``` #### Parameters `value` [T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T') The value of the new node\. Cannot be `null`\. `disable` [System\.Boolean](https://learn.microsoft.com/en-us/dotnet/api/system.boolean 'System\.Boolean') When `true`, the new node cannot be checked\. Default is `false`\. `check` [System\.Boolean](https://learn.microsoft.com/en-us/dotnet/api/system.boolean 'System\.Boolean') Same semantics as in [Root\(T, bool, bool\)](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.Root(T,bool,bool) 'PromptPlusLibrary\.ITreeMultiSelectControl\\.Root\(T, bool, bool\)')\. #### Returns [PromptPlusLibrary\.ITreeMultiSelectNode<](ITreeMultiSelectNode_T_.md 'PromptPlusLibrary\.ITreeMultiSelectNode\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectNode_T_.md 'PromptPlusLibrary\.ITreeMultiSelectNode\') ## ITreeMultiSelectControl\\.AddLast\(T, bool, bool\) Method Adds a new node as the last child of the root and returns it so children can be appended to it\. ```csharp PromptPlusLibrary.ITreeMultiSelectNode AddLast(T value, bool disable=false, bool check=false); ``` #### Parameters `value` [T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T') The value of the new node\. Cannot be `null`\. `disable` [System\.Boolean](https://learn.microsoft.com/en-us/dotnet/api/system.boolean 'System\.Boolean') When `true`, the new node cannot be checked\. Default is `false`\. `check` [System\.Boolean](https://learn.microsoft.com/en-us/dotnet/api/system.boolean 'System\.Boolean') Same semantics as in [Root\(T, bool, bool\)](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.Root(T,bool,bool) 'PromptPlusLibrary\.ITreeMultiSelectControl\\.Root\(T, bool, bool\)')\. #### Returns [PromptPlusLibrary\.ITreeMultiSelectNode<](ITreeMultiSelectNode_T_.md 'PromptPlusLibrary\.ITreeMultiSelectNode\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectNode_T_.md 'PromptPlusLibrary\.ITreeMultiSelectNode\') ## ITreeMultiSelectControl\\.CascadeCheck\(bool\) Method When `true` \(default\), checking/unchecking a container propagates the new state to all its descendants\. When `false`, only the container itself is toggled\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl CascadeCheck(bool value=true); ``` #### Parameters `value` [System\.Boolean](https://learn.microsoft.com/en-us/dotnet/api/system.boolean 'System\.Boolean') #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') ## ITreeMultiSelectControl\\.ChangeDescription\(Func\\) Method Dynamically updates the description area based on the node currently under the cursor\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl ChangeDescription(System.Func value); ``` #### Parameters `value` [System\.Func<](https://learn.microsoft.com/en-us/dotnet/api/system.func-2 'System\.Func\`2')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[,](https://learn.microsoft.com/en-us/dotnet/api/system.func-2 'System\.Func\`2')[System\.String](https://learn.microsoft.com/en-us/dotnet/api/system.string 'System\.String')[>](https://learn.microsoft.com/en-us/dotnet/api/system.func-2 'System\.Func\`2') #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') ## ITreeMultiSelectControl\\.ChangeDescriptionAsync\(Func\\>\) Method Asynchronous variant of [ChangeDescription\(Func<T,string>\)](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.ChangeDescription(System.Func_T,string_) 'PromptPlusLibrary\.ITreeMultiSelectControl\\.ChangeDescription\(System\.Func\\)')\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl ChangeDescriptionAsync(System.Func> value); ``` #### Parameters `value` [System\.Func<](https://learn.microsoft.com/en-us/dotnet/api/system.func-2 'System\.Func\`2')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[,](https://learn.microsoft.com/en-us/dotnet/api/system.func-2 'System\.Func\`2')[System\.Threading\.Tasks\.Task<](https://learn.microsoft.com/en-us/dotnet/api/system.threading.tasks.task-1 'System\.Threading\.Tasks\.Task\`1')[System\.String](https://learn.microsoft.com/en-us/dotnet/api/system.string 'System\.String')[>](https://learn.microsoft.com/en-us/dotnet/api/system.threading.tasks.task-1 'System\.Threading\.Tasks\.Task\`1')[>](https://learn.microsoft.com/en-us/dotnet/api/system.func-2 'System\.Func\`2') #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') ## ITreeMultiSelectControl\\.CheckLeafOnly\(bool\) Method When `true`, only leaf nodes \(nodes without children\) can be checked\. Checking a container is blocked\. Default is `false`\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl CheckLeafOnly(bool value=true); ``` #### Parameters `value` [System\.Boolean](https://learn.microsoft.com/en-us/dotnet/api/system.boolean 'System\.Boolean') #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') ## ITreeMultiSelectControl\\.Default\(IEnumerable\, bool\) Method Pre\-checks one or more items\. The tree auto\-expands to each pre\-checked node\. When [useDefaultHistory](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.Default(System.Collections.Generic.IEnumerable_T_,bool).useDefaultHistory 'PromptPlusLibrary\.ITreeMultiSelectControl\\.Default\(System\.Collections\.Generic\.IEnumerable\, bool\)\.useDefaultHistory') is `true` and history is enabled, the history values override [values](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.Default(System.Collections.Generic.IEnumerable_T_,bool).values 'PromptPlusLibrary\.ITreeMultiSelectControl\\.Default\(System\.Collections\.Generic\.IEnumerable\, bool\)\.values')\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl Default(System.Collections.Generic.IEnumerable values, bool useDefaultHistory=true); ``` #### Parameters `values` [System\.Collections\.Generic\.IEnumerable<](https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.ienumerable-1 'System\.Collections\.Generic\.IEnumerable\`1')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.ienumerable-1 'System\.Collections\.Generic\.IEnumerable\`1') `useDefaultHistory` [System\.Boolean](https://learn.microsoft.com/en-us/dotnet/api/system.boolean 'System\.Boolean') #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') ## ITreeMultiSelectControl\\.DefaultMatchBy\(Func\\) Method Sets the equality comparer used to match items \(e\.g\. for [Default\(IEnumerable<T>, bool\)](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.Default(System.Collections.Generic.IEnumerable_T_,bool) 'PromptPlusLibrary\.ITreeMultiSelectControl\\.Default\(System\.Collections\.Generic\.IEnumerable\, bool\)') lookup\)\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl DefaultMatchBy(System.Func comparer); ``` #### Parameters `comparer` [System\.Func<](https://learn.microsoft.com/en-us/dotnet/api/system.func-3 'System\.Func\`3')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[,](https://learn.microsoft.com/en-us/dotnet/api/system.func-3 'System\.Func\`3')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[,](https://learn.microsoft.com/en-us/dotnet/api/system.func-3 'System\.Func\`3')[System\.Boolean](https://learn.microsoft.com/en-us/dotnet/api/system.boolean 'System\.Boolean')[>](https://learn.microsoft.com/en-us/dotnet/api/system.func-3 'System\.Func\`3') #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') ## ITreeMultiSelectControl\\.EnableHistory\(string, Action\\) Method Enables history persistence\. Previously checked items are restored on next run\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl EnableHistory(string filename, System.Action? options=null); ``` #### Parameters `filename` [System\.String](https://learn.microsoft.com/en-us/dotnet/api/system.string 'System\.String') `options` [System\.Action<](https://learn.microsoft.com/en-us/dotnet/api/system.action-1 'System\.Action\`1')[IHistoryOptions](IHistoryOptions.md 'PromptPlusLibrary\.IHistoryOptions')[>](https://learn.microsoft.com/en-us/dotnet/api/system.action-1 'System\.Action\`1') #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') ## ITreeMultiSelectControl\\.ExtraInfo\(Func\\) Method Sets a function that returns optional extra information rendered next to each node label\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl ExtraInfo(System.Func extraInfoNode); ``` #### Parameters `extraInfoNode` [System\.Func<](https://learn.microsoft.com/en-us/dotnet/api/system.func-2 'System\.Func\`2')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[,](https://learn.microsoft.com/en-us/dotnet/api/system.func-2 'System\.Func\`2')[System\.String](https://learn.microsoft.com/en-us/dotnet/api/system.string 'System\.String')[>](https://learn.microsoft.com/en-us/dotnet/api/system.func-2 'System\.Func\`2') #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') #### Exceptions [System\.ArgumentNullException](https://learn.microsoft.com/en-us/dotnet/api/system.argumentnullexception 'System\.ArgumentNullException') When [extraInfoNode](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.ExtraInfo(System.Func_T,string_).extraInfoNode 'PromptPlusLibrary\.ITreeMultiSelectControl\\.ExtraInfo\(System\.Func\\)\.extraInfoNode') is `null`\. ## ITreeMultiSelectControl\\.ExtraInfoAsync\(Func\\>\) Method Asynchronous counterpart of [ExtraInfo\(Func<T,string>\)](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.ExtraInfo(System.Func_T,string_) 'PromptPlusLibrary\.ITreeMultiSelectControl\\.ExtraInfo\(System\.Func\\)')\. The task is awaited synchronously \(blocking\) once per node, per render frame\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl ExtraInfoAsync(System.Func> extraInfoNode); ``` #### Parameters `extraInfoNode` [System\.Func<](https://learn.microsoft.com/en-us/dotnet/api/system.func-2 'System\.Func\`2')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[,](https://learn.microsoft.com/en-us/dotnet/api/system.func-2 'System\.Func\`2')[System\.Threading\.Tasks\.Task<](https://learn.microsoft.com/en-us/dotnet/api/system.threading.tasks.task-1 'System\.Threading\.Tasks\.Task\`1')[System\.String](https://learn.microsoft.com/en-us/dotnet/api/system.string 'System\.String')[>](https://learn.microsoft.com/en-us/dotnet/api/system.threading.tasks.task-1 'System\.Threading\.Tasks\.Task\`1')[>](https://learn.microsoft.com/en-us/dotnet/api/system.func-2 'System\.Func\`2') #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') #### Exceptions [System\.ArgumentNullException](https://learn.microsoft.com/en-us/dotnet/api/system.argumentnullexception 'System\.ArgumentNullException') When [extraInfoNode](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.ExtraInfoAsync(System.Func_T,System.Threading.Tasks.Task_string__).extraInfoNode 'PromptPlusLibrary\.ITreeMultiSelectControl\\.ExtraInfoAsync\(System\.Func\\>\)\.extraInfoNode') is `null`\. ## ITreeMultiSelectControl\\.Filter\(FilterMode\) Method Sets the filter strategy for the filter mode\. Default is [Disabled](FilterMode.md#PromptPlusLibrary.FilterMode.Disabled 'PromptPlusLibrary\.FilterMode\.Disabled')\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl Filter(PromptPlusLibrary.FilterMode value); ``` #### Parameters `value` [FilterMode](FilterMode.md 'PromptPlusLibrary\.FilterMode') #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') ## ITreeMultiSelectControl\\.Interaction\\(IEnumerable\, Action\\>\) Method Iterates over [items](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.Interaction_T1_(System.Collections.Generic.IEnumerable_T1_,System.Action_T1,PromptPlusLibrary.ITreeMultiSelectControl_T__).items 'PromptPlusLibrary\.ITreeMultiSelectControl\\.Interaction\\(System\.Collections\.Generic\.IEnumerable\, System\.Action\\>\)\.items') and invokes [interactionAction](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.Interaction_T1_(System.Collections.Generic.IEnumerable_T1_,System.Action_T1,PromptPlusLibrary.ITreeMultiSelectControl_T__).interactionAction 'PromptPlusLibrary\.ITreeMultiSelectControl\\.Interaction\\(System\.Collections\.Generic\.IEnumerable\, System\.Action\\>\)\.interactionAction') for each element, allowing bulk population of the tree\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl Interaction(System.Collections.Generic.IEnumerable items, System.Action> interactionAction); ``` #### Type parameters `T1` #### Parameters `items` [System\.Collections\.Generic\.IEnumerable<](https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.ienumerable-1 'System\.Collections\.Generic\.IEnumerable\`1')[T1](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.Interaction_T1_(System.Collections.Generic.IEnumerable_T1_,System.Action_T1,PromptPlusLibrary.ITreeMultiSelectControl_T__).T1 'PromptPlusLibrary\.ITreeMultiSelectControl\\.Interaction\\(System\.Collections\.Generic\.IEnumerable\, System\.Action\\>\)\.T1')[>](https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.ienumerable-1 'System\.Collections\.Generic\.IEnumerable\`1') `interactionAction` [System\.Action<](https://learn.microsoft.com/en-us/dotnet/api/system.action-2 'System\.Action\`2')[T1](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.Interaction_T1_(System.Collections.Generic.IEnumerable_T1_,System.Action_T1,PromptPlusLibrary.ITreeMultiSelectControl_T__).T1 'PromptPlusLibrary\.ITreeMultiSelectControl\\.Interaction\\(System\.Collections\.Generic\.IEnumerable\, System\.Action\\>\)\.T1')[,](https://learn.microsoft.com/en-us/dotnet/api/system.action-2 'System\.Action\`2')[PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[>](https://learn.microsoft.com/en-us/dotnet/api/system.action-2 'System\.Action\`2') #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') ## ITreeMultiSelectControl\\.InteractionAsync\\(IEnumerable\, Func\,Task\>\) Method Asynchronous variant of [Interaction<T1>\(IEnumerable<T1>, Action<T1,ITreeMultiSelectControl<T>>\)](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.Interaction_T1_(System.Collections.Generic.IEnumerable_T1_,System.Action_T1,PromptPlusLibrary.ITreeMultiSelectControl_T__) 'PromptPlusLibrary\.ITreeMultiSelectControl\\.Interaction\\(System\.Collections\.Generic\.IEnumerable\, System\.Action\\>\)')\. Each callback is awaited synchronously so the tree is fully populated before `Run` is called\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl InteractionAsync(System.Collections.Generic.IEnumerable items, System.Func,System.Threading.Tasks.Task> interactionAction); ``` #### Type parameters `T1` #### Parameters `items` [System\.Collections\.Generic\.IEnumerable<](https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.ienumerable-1 'System\.Collections\.Generic\.IEnumerable\`1')[T1](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.InteractionAsync_T1_(System.Collections.Generic.IEnumerable_T1_,System.Func_T1,PromptPlusLibrary.ITreeMultiSelectControl_T_,System.Threading.Tasks.Task_).T1 'PromptPlusLibrary\.ITreeMultiSelectControl\\.InteractionAsync\\(System\.Collections\.Generic\.IEnumerable\, System\.Func\,System\.Threading\.Tasks\.Task\>\)\.T1')[>](https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.ienumerable-1 'System\.Collections\.Generic\.IEnumerable\`1') `interactionAction` [System\.Func<](https://learn.microsoft.com/en-us/dotnet/api/system.func-3 'System\.Func\`3')[T1](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.InteractionAsync_T1_(System.Collections.Generic.IEnumerable_T1_,System.Func_T1,PromptPlusLibrary.ITreeMultiSelectControl_T_,System.Threading.Tasks.Task_).T1 'PromptPlusLibrary\.ITreeMultiSelectControl\\.InteractionAsync\\(System\.Collections\.Generic\.IEnumerable\, System\.Func\,System\.Threading\.Tasks\.Task\>\)\.T1')[,](https://learn.microsoft.com/en-us/dotnet/api/system.func-3 'System\.Func\`3')[PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[,](https://learn.microsoft.com/en-us/dotnet/api/system.func-3 'System\.Func\`3')[System\.Threading\.Tasks\.Task](https://learn.microsoft.com/en-us/dotnet/api/system.threading.tasks.task 'System\.Threading\.Tasks\.Task')[>](https://learn.microsoft.com/en-us/dotnet/api/system.func-3 'System\.Func\`3') #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') ## ITreeMultiSelectControl\\.Options\(Action\\) Method Applies custom options to the control\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl Options(System.Action options); ``` #### Parameters `options` [System\.Action<](https://learn.microsoft.com/en-us/dotnet/api/system.action-1 'System\.Action\`1')[IControlOptions](IControlOptions.md 'PromptPlusLibrary\.IControlOptions')[>](https://learn.microsoft.com/en-us/dotnet/api/system.action-1 'System\.Action\`1') #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') ## ITreeMultiSelectControl\\.PageSize\(byte\) Method Sets the maximum number of visible rows per page\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl PageSize(byte value); ``` #### Parameters `value` [System\.Byte](https://learn.microsoft.com/en-us/dotnet/api/system.byte 'System\.Byte') #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') ## ITreeMultiSelectControl\\.PathSeparator\(char\) Method Sets the path separator character used when showing full paths\. Default is `'/'`\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl PathSeparator(char value); ``` #### Parameters `value` [System\.Char](https://learn.microsoft.com/en-us/dotnet/api/system.char 'System\.Char') #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') ## ITreeMultiSelectControl\\.PredicateChecked\(Func\\) Method Sets a predicate that decides whether a node can be checked\. Nodes that fail the predicate show an error when the user tries to check them\. Only evaluated when marking a node as checked — unchecking an already\-checked node is always allowed \(subject only to it not being disabled\) and never runs this predicate\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl PredicateChecked(System.Func validselect); ``` #### Parameters `validselect` [System\.Func<](https://learn.microsoft.com/en-us/dotnet/api/system.func-2 'System\.Func\`2')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[,](https://learn.microsoft.com/en-us/dotnet/api/system.func-2 'System\.Func\`2')[System\.Boolean](https://learn.microsoft.com/en-us/dotnet/api/system.boolean 'System\.Boolean')[>](https://learn.microsoft.com/en-us/dotnet/api/system.func-2 'System\.Func\`2') #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') ## ITreeMultiSelectControl\\.PredicateCheckedAsync\(Func\\>\) Method Asynchronous variant of [PredicateChecked\(Func<T,bool>\)](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.PredicateChecked(System.Func_T,bool_) 'PromptPlusLibrary\.ITreeMultiSelectControl\\.PredicateChecked\(System\.Func\\)')\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl PredicateCheckedAsync(System.Func> validselect); ``` #### Parameters `validselect` [System\.Func<](https://learn.microsoft.com/en-us/dotnet/api/system.func-2 'System\.Func\`2')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[,](https://learn.microsoft.com/en-us/dotnet/api/system.func-2 'System\.Func\`2')[System\.Threading\.Tasks\.Task<](https://learn.microsoft.com/en-us/dotnet/api/system.threading.tasks.task-1 'System\.Threading\.Tasks\.Task\`1')[System\.Boolean](https://learn.microsoft.com/en-us/dotnet/api/system.boolean 'System\.Boolean')[>](https://learn.microsoft.com/en-us/dotnet/api/system.threading.tasks.task-1 'System\.Threading\.Tasks\.Task\`1')[>](https://learn.microsoft.com/en-us/dotnet/api/system.func-2 'System\.Func\`2') #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') ## ITreeMultiSelectControl\\.Range\(int, Nullable\\) Method Defines the valid range for the number of checked items\. Confirmation is blocked until the count falls within `[minvalue, maxvalue]`\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl Range(int minvalue, System.Nullable maxvalue=null); ``` #### Parameters `minvalue` [System\.Int32](https://learn.microsoft.com/en-us/dotnet/api/system.int32 'System\.Int32') Minimum number of checked items \(≥ 0\)\. `maxvalue` [System\.Nullable<](https://learn.microsoft.com/en-us/dotnet/api/system.nullable-1 'System\.Nullable\`1')[System\.Int32](https://learn.microsoft.com/en-us/dotnet/api/system.int32 'System\.Int32')[>](https://learn.microsoft.com/en-us/dotnet/api/system.nullable-1 'System\.Nullable\`1') Optional maximum\. When `null` there is no upper bound\. #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') ## ITreeMultiSelectControl\\.RecursiveMarkWithCtrlSpace\(bool\) Method Enables using `Ctrl+Space` for the recursive container selection \(check/uncheck the container and all descendants\)\. When enabled, plain `Space` only toggles the checked state of the selected node itself, and the recursive action is moved to `Ctrl+Space`\. When disabled \(default\), plain `Space` performs the recursive selection on containers \(if [CascadeCheck\(bool\)](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.CascadeCheck(bool) 'PromptPlusLibrary\.ITreeMultiSelectControl\\.CascadeCheck\(bool\)') is `true`\)\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl RecursiveMarkWithCtrlSpace(bool value=true); ``` #### Parameters `value` [System\.Boolean](https://learn.microsoft.com/en-us/dotnet/api/system.boolean 'System\.Boolean') `true` to use `Ctrl+Space` for recursive marking; otherwise, `false`\. #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') The same [ITreeMultiSelectControl<T>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') instance for chaining\. ## ITreeMultiSelectControl\\.Root\(T, bool, bool\) Method Sets the root value of the tree\. Must be called before adding any children\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl Root(T value, bool disable=false, bool check=false); ``` #### Parameters `value` [T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T') The root value\. Cannot be `null`\. `disable` [System\.Boolean](https://learn.microsoft.com/en-us/dotnet/api/system.boolean 'System\.Boolean') When `true`, the root cannot be checked\. Default is `false`\. `check` [System\.Boolean](https://learn.microsoft.com/en-us/dotnet/api/system.boolean 'System\.Boolean') When `true`, the root starts pre\-checked\. Additive with [Default\(IEnumerable<T>, bool\)](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.Default(System.Collections.Generic.IEnumerable_T_,bool) 'PromptPlusLibrary\.ITreeMultiSelectControl\\.Default\(System\.Collections\.Generic\.IEnumerable\, bool\)')/ history — whichever marks it, it stays checked\. Subject to cascade the same way an interactive check would be; does not auto\-expand the tree to reveal it \(unlike [Default\(IEnumerable<T>, bool\)](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.Default(System.Collections.Generic.IEnumerable_T_,bool) 'PromptPlusLibrary\.ITreeMultiSelectControl\\.Default\(System\.Collections\.Generic\.IEnumerable\, bool\)')\)\. #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') #### Exceptions [System\.ArgumentNullException](https://learn.microsoft.com/en-us/dotnet/api/system.argumentnullexception 'System\.ArgumentNullException') Thrown when [value](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.Root(T,bool,bool).value 'PromptPlusLibrary\.ITreeMultiSelectControl\\.Root\(T, bool, bool\)\.value') is `null`\. ## ITreeMultiSelectControl\\.Run\(CancellationToken\) Method Runs the TreeMultiSelect control and returns the result\. ```csharp PromptPlusLibrary.ResultPrompt Run(System.Threading.CancellationToken token=default(System.Threading.CancellationToken)); ``` #### Parameters `token` [System\.Threading\.CancellationToken](https://learn.microsoft.com/en-us/dotnet/api/system.threading.cancellationtoken 'System\.Threading\.CancellationToken') Cancellation token\. Defaults to [System\.Threading\.CancellationToken\.None](https://learn.microsoft.com/en-us/dotnet/api/system.threading.cancellationtoken.none 'System\.Threading\.CancellationToken\.None')\. #### Returns [PromptPlusLibrary\.ResultPrompt<](ResultPrompt_T_.md 'PromptPlusLibrary\.ResultPrompt\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[\[\]](https://learn.microsoft.com/en-us/dotnet/api/system.array 'System\.Array')[>](ResultPrompt_T_.md 'PromptPlusLibrary\.ResultPrompt\') A [ResultPrompt<T>](ResultPrompt_T_.md 'PromptPlusLibrary\.ResultPrompt\') whose `Content` is the array of checked values, or an aborted result if the user cancelled\. ## ITreeMultiSelectControl\\.ShowFullPath\(bool\) Method When `true`, the answer line shows the full ancestor path for each checked item instead of just its own name\. Default is `false`\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl ShowFullPath(bool value=true); ``` #### Parameters `value` [System\.Boolean](https://learn.microsoft.com/en-us/dotnet/api/system.boolean 'System\.Boolean') #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') ## ITreeMultiSelectControl\\.Styles\(TreeMultiSelectStyles, Style\) Method Overrides a style region for the TreeMultiSelect control\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl Styles(PromptPlusLibrary.TreeMultiSelectStyles styleType, ConsolePlusLibrary.Style style); ``` #### Parameters `styleType` [TreeMultiSelectStyles](TreeMultiSelectStyles.md 'PromptPlusLibrary\.TreeMultiSelectStyles') `style` [ConsolePlusLibrary\.Style](https://learn.microsoft.com/en-us/dotnet/api/consolepluslibrary.style 'ConsolePlusLibrary\.Style') #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') ## ITreeMultiSelectControl\\.TextSelector\(Func\\) Method Sets the function used to obtain the display text for each node\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl TextSelector(System.Func selector); ``` #### Parameters `selector` [System\.Func<](https://learn.microsoft.com/en-us/dotnet/api/system.func-2 'System\.Func\`2')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[,](https://learn.microsoft.com/en-us/dotnet/api/system.func-2 'System\.Func\`2')[System\.String](https://learn.microsoft.com/en-us/dotnet/api/system.string 'System\.String')[>](https://learn.microsoft.com/en-us/dotnet/api/system.func-2 'System\.Func\`2') #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\') ## ITreeMultiSelectControl\\.ViewOnly\(bool\) Method Puts the control into view\-only mode\. The user can navigate and expand/collapse the tree but cannot check items\. Enter returns the pre\-checked defaults\. ```csharp PromptPlusLibrary.ITreeMultiSelectControl ViewOnly(bool value=true); ``` #### Parameters `value` [System\.Boolean](https://learn.microsoft.com/en-us/dotnet/api/system.boolean 'System\.Boolean') #### Returns [PromptPlusLibrary\.ITreeMultiSelectControl<](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')[T](ITreeMultiSelectControl_T_.md#PromptPlusLibrary.ITreeMultiSelectControl_T_.T 'PromptPlusLibrary\.ITreeMultiSelectControl\\.T')[>](ITreeMultiSelectControl_T_.md 'PromptPlusLibrary\.ITreeMultiSelectControl\')