public:
event System::Windows::Forms::TreeViewEventHandler ^ AfterCheck;
public event System.Windows.Forms.TreeViewEventHandler AfterCheck;
member this.AfterCheck : System.Windows.Forms.TreeViewEventHandler
Public Custom Event AfterCheck As TreeViewEventHandler
下面的代码示例在用户更改其选中状态时更新 的所有子树节点
TreeNode
。 此代码要求具有
Form
的 ，
TreeView
其
TreeNodeCollection
中具有
TreeNode
对象。 应
TreeNodeCollection
具有具有子节点的树节点。
// Updates all child tree nodes recursively.
void CheckAllChildNodes( TreeNode^ treeNode, bool nodeChecked )
IEnumerator^ myEnum = treeNode->Nodes->GetEnumerator();
while ( myEnum->MoveNext() )
TreeNode^ node = safe_cast<TreeNode^>(myEnum->Current);
node->Checked = nodeChecked;
if ( node->Nodes->Count > 0 )
// If the current node has child nodes, call the CheckAllChildsNodes method recursively.
this->CheckAllChildNodes( node, nodeChecked );
// NOTE This code can be added to the BeforeCheck event handler instead of the AfterCheck event.
// After a tree node's Checked property is changed, all its child nodes are updated to the same value.
void node_AfterCheck( Object^ /*sender*/, TreeViewEventArgs^ e )
// The code only executes if the user caused the checked state to change.
if ( e->Action != TreeViewAction::Unknown )
if ( e->Node->Nodes->Count > 0 )
/* Calls the CheckAllChildNodes method, passing in the current
Checked value of the TreeNode whose checked state changed. */
this->CheckAllChildNodes( e->Node, e->Node->Checked );
// Updates all child tree nodes recursively.
private void CheckAllChildNodes(TreeNode treeNode, bool nodeChecked)
foreach(TreeNode node in treeNode.Nodes)
node.Checked = nodeChecked;
if(node.Nodes.Count > 0)
// If the current node has child nodes, call the CheckAllChildsNodes method recursively.
this.CheckAllChildNodes(node, nodeChecked);
// NOTE This code can be added to the BeforeCheck event handler instead of the AfterCheck event.
// After a tree node's Checked property is changed, all its child nodes are updated to the same value.
private void node_AfterCheck(object sender, TreeViewEventArgs e)
// The code only executes if the user caused the checked state to change.
if(e.Action != TreeViewAction.Unknown)
if(e.Node.Nodes.Count > 0)
/* Calls the CheckAllChildNodes method, passing in the current
Checked value of the TreeNode whose checked state changed. */
this.CheckAllChildNodes(e.Node, e.Node.Checked);
' Updates all child tree nodes recursively.
Private Sub CheckAllChildNodes(treeNode As TreeNode, nodeChecked As Boolean)
Dim node As TreeNode
For Each node In treeNode.Nodes
node.Checked = nodeChecked
If node.Nodes.Count > 0 Then
' If the current node has child nodes, call the CheckAllChildsNodes method recursively.
Me.CheckAllChildNodes(node, nodeChecked)
End If
Next node
End Sub
' NOTE This code can be added to the BeforeCheck event handler instead of the AfterCheck event.
' After a tree node's Checked property is changed, all its child nodes are updated to the same value.
Private Sub node_AfterCheck(sender As Object, e As TreeViewEventArgs) Handles treeView1.AfterCheck
' The code only executes if the user caused the checked state to change.
If e.Action <> TreeViewAction.Unknown Then
If e.Node.Nodes.Count > 0 Then
' Calls the CheckAllChildNodes method, passing in the current
' Checked value of the TreeNode whose checked state changed.
Me.CheckAllChildNodes(e.Node, e.Node.Checked)
End If
End If
End Sub
TreeNode.Checked
从 或
AfterCheck
事件处理程序中
BeforeCheck
设置 属性会导致多次引发事件，并可能导致意外行为。 若要防止多次引发事件，请将逻辑添加到事件处理程序，该处理程序仅在 的 属性
TreeViewEventArgs
未设置为
TreeViewAction.Unknown
时
Action
执行递归代码。
有关处理事件的详细信息，请参阅
处理和引发事件
。
