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TreeNodeCollection.Clear Method

Removes all tree nodes from the collection.

[Visual Basic]
Public Overridable Sub Clear() Implements IList.Clear
[C#]
public virtual void Clear();
[C++]
public: virtual void Clear();
[JScript]
public function Clear();

Implements

IList.Clear

Remarks

You can use this method to clear the entire collection of tree nodes from a tree view.

To remove an individual tree node from the collection, use the Remove or RemoveAt methods.

To add new TreeNode objects to the collection, use the Add, AddRange or Insert methods.

Example

[Visual Basic, C#, C++] The following example copies the TreeNodeCollection from a TreeView to a temporary Array, then adds the contents of the array to another TreeView using the AddRange method. The TreeNodeCollection from the source TreeView is cleared using the Clear method. This example assumes you have two TreeView controls, one with a collection of TreeNode objects.

[Visual Basic] 
Private Sub MyButtonAddAllClick(sender As Object, e As EventArgs)
   ' Get the 'myTreeNodeCollection' from the 'myTreeViewBase' TreeView.
   Dim myTreeNodeCollection As TreeNodeCollection = myTreeViewBase.Nodes
   ' Create an array of 'TreeNodes'.
   Dim myTreeNodeArray(myTreeViewBase.Nodes.Count-1) As TreeNode
   ' Copy the tree nodes to the 'myTreeNodeArray' array.
   myTreeViewBase.Nodes.CopyTo(myTreeNodeArray, 0)
   ' Remove all the tree nodes from the 'myTreeViewBase' TreeView.
   myTreeViewBase.Nodes.Clear()
   ' Add the 'myTreeNodeArray' to the 'myTreeViewCustom' TreeView.
      myTreeViewCustom.Nodes.AddRange(myTreeNodeArray)
End Sub

[C#] 
private void MyButtonAddAllClick(object sender, EventArgs e)
{
   // Get the 'myTreeNodeCollection' from the 'myTreeViewBase' TreeView.
   TreeNodeCollection myTreeNodeCollection = myTreeViewBase.Nodes;
   // Create an array of 'TreeNodes'.
   TreeNode[] myTreeNodeArray = new TreeNode[myTreeViewBase.Nodes.Count];
   // Copy the tree nodes to the 'myTreeNodeArray' array.
   myTreeViewBase.Nodes.CopyTo(myTreeNodeArray,0);
   // Remove all the tree nodes from the 'myTreeViewBase' TreeView.
   myTreeViewBase.Nodes.Clear();
   // Add the 'myTreeNodeArray' to the 'myTreeViewCustom' TreeView.
   myTreeViewCustom.Nodes.AddRange(myTreeNodeArray);
}

[C++] 
private:
    void MyButtonAddAllClick(Object* /*sender*/, EventArgs* /*e*/) {
        // Get the 'myTreeNodeCollection' from the 'myTreeViewBase' TreeView.
        TreeNodeCollection* myTreeNodeCollection = myTreeViewBase->Nodes;
        // Create an array of 'TreeNodes'.
        TreeNode* myTreeNodeArray[] = new TreeNode*[myTreeViewBase->Nodes->Count];
        // Copy the tree nodes to the 'myTreeNodeArray' array.
        myTreeViewBase->Nodes->CopyTo(myTreeNodeArray, 0);
        // Remove all the tree nodes from the 'myTreeViewBase' TreeView.
        myTreeViewBase->Nodes->Clear();
        // Add the 'myTreeNodeArray' to the 'myTreeViewCustom' TreeView.
        myTreeViewCustom->Nodes->AddRange(myTreeNodeArray);
    }

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework

See Also

TreeNodeCollection Class | TreeNodeCollection Members | System.Windows.Forms Namespace

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