TreeNodeCollection.Contains(TreeNode) 方法

public:
 bool Contains(System::Windows::Forms::TreeNode ^ node);

public bool Contains(System.Windows.Forms.TreeNode node);

member this.Contains : System.Windows.Forms.TreeNode -> bool

Public Function Contains (node As TreeNode) As Boolean

参数

返回

如果集合是集合的成员，则为 否则为 。

示例

下面的代码示例确定指定 TreeNode 是否在集合 TreeNodeCollection中，然后枚举集合。 此示例要求你有一个FormTreeView包含TreeNodeCollectionTreeNode命名名称myTreeNode2的项。

void EnumerateTreeNodes()
{
   TreeNodeCollection^ myNodeCollection = myTreeView->Nodes;

   // Check for a node in the collection.
   if ( myNodeCollection->Contains( myTreeNode2 ) )
   {
      myLabel->Text = myLabel->Text + "Node2 is at index: " + myNodeCollection->IndexOf( myTreeNode2 );
   }

   myLabel->Text = myLabel->Text + "\n\nElements of the TreeNodeCollection:\n";

   // Create an enumerator for the collection.
   IEnumerator^ myEnumerator = myNodeCollection->GetEnumerator();
   while ( myEnumerator->MoveNext() )
   {
      myLabel->Text = myLabel->Text + (dynamic_cast<TreeNode^>(myEnumerator->Current))->Text + "\n";
   }
}

private void EnumerateTreeNodes()
{
   TreeNodeCollection myNodeCollection = myTreeView.Nodes;
   // Check for a node in the collection.
   if (myNodeCollection.Contains(myTreeNode2))
   {
      myLabel.Text += "Node2 is at index: " + myNodeCollection.IndexOf(myTreeNode2);
   }
   myLabel.Text += "\n\nElements of the TreeNodeCollection:\n";

   // Create an enumerator for the collection.
   IEnumerator myEnumerator = myNodeCollection.GetEnumerator();
   while(myEnumerator.MoveNext())
   {
      myLabel.Text += ((TreeNode)myEnumerator.Current).Text +"\n";
   }
}

Private Sub EnumerateTreeNodes()
   Dim myNodeCollection As TreeNodeCollection = myTreeView.Nodes
   ' Check for a node in the collection.
   If myNodeCollection.Contains(myTreeNode2) Then
      myLabel.Text += "Node2 is at index: " + myNodeCollection.IndexOf(myTreeNode2)
   End If
   myLabel.Text += ControlChars.Cr + ControlChars.Cr + _
     "Elements of the TreeNodeCollection:" + ControlChars.Cr
   
   ' Create an enumerator for the collection.
   Dim myEnumerator As IEnumerator = myNodeCollection.GetEnumerator()
   While myEnumerator.MoveNext()
      myLabel.Text += CType(myEnumerator.Current, TreeNode).Text + ControlChars.Cr
   End While
End Sub

注解

此方法使你能够在尝试对TreeNode集合执行操作之前确定是否TreeNode是集合的成员。 可以使用此方法确认 TreeNode 已添加到集合中还是仍然是集合的成员。

此方法花费的时间量与节点集合的大小成正比，因此你可能希望避免将它与大型集合一起使用。

此方法仅检查引用相等性。 不能使用它来确定集合中是否具有等效但不同的节点。