TreeView.GetNodeAt 方法

定义

命名空间:

System.Windows.Forms

程序集:

System.Windows.Forms.dll

检索位于指定位置的树节点。

重载

GetNodeAt(Point)	检索位于指定点的树节点。
GetNodeAt(Int32, Int32)	检索位于指定点（以坐标表示）的树节点。

GetNodeAt(Point)

Source:

TreeView.cs

检索位于指定点的树节点。

public:
 System::Windows::Forms::TreeNode ^ GetNodeAt(System::Drawing::Point pt);

public System.Windows.Forms.TreeNode? GetNodeAt (System.Drawing.Point pt);

member this.GetNodeAt : System.Drawing.Point -> System.Windows.Forms.TreeNode

Public Function GetNodeAt (pt As Point) As TreeNode

参数

pt

Point

要从其计算和检索节点的 Point。

返回

TreeNode

位于以树视图（客户端）坐标表示的指定点的 TreeNode，或在该位置没有节点时为 null。

注解

可以将 事件的 和 坐标作为新 的 和 Y 值传递MouseEventArgs.X。XPointMouseDownMouseEventArgs.Y

另请参阅

• Point

GetNodeAt(Int32, Int32)

Source:

TreeView.cs

检索位于指定点（以坐标表示）的树节点。

public:
 System::Windows::Forms::TreeNode ^ GetNodeAt(int x, int y);

public System.Windows.Forms.TreeNode? GetNodeAt (int x, int y);

member this.GetNodeAt : int * int -> System.Windows.Forms.TreeNode

Public Function GetNodeAt (x As Integer, y As Integer) As TreeNode

参数

x

Int32

要从其计算和检索节点的 X 位置。

y

Int32

要从其计算和检索节点的 Y 位置。

返回

TreeNode

位于以树视图（客户端）坐标表示的指定位置的 TreeNode，或在该位置没有节点时为 null。

示例

下面的代码示例允许用户使用 ContextMenu编辑非根树节点。 当用户右键单击鼠标时， TreeNode 确定该位置的 并将其存储在名为 的 mySelectedNode变量中。 如果选择了非根树节点，则会将其置于可编辑状态，从而允许用户编辑节点标签。 用户停止编辑树节点标签后，将计算并保存新标签文本。 在此示例中，标签文本中将多个字符视为无效。 如果标签字符串中存在一个无效字符，或者该字符串为空，则会通知用户错误，并将标签返回到以前的文本。

   /* Get the tree node under the mouse pointer and 
      save it in the mySelectedNode variable. */
private:
   void treeView1_MouseDown( Object^ /*sender*/, System::Windows::Forms::MouseEventArgs^ e )
   {
      mySelectedNode = treeView1->GetNodeAt( e->X, e->Y );
   }

   void menuItem1_Click( Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      if ( mySelectedNode != nullptr && mySelectedNode->Parent != nullptr )
      {
         treeView1->SelectedNode = mySelectedNode;
         treeView1->LabelEdit = true;
         if (  !mySelectedNode->IsEditing )
         {
            mySelectedNode->BeginEdit();
         }
      }
      else
      {
         MessageBox::Show( String::Concat( "No tree node selected or selected node is a root node.\n",
            "Editing of root nodes is not allowed." ), "Invalid selection" );
      }
   }

   void treeView1_AfterLabelEdit( Object^ /*sender*/,
      System::Windows::Forms::NodeLabelEditEventArgs^ e )
   {
      if ( e->Label != nullptr )
      {
         if ( e->Label->Length > 0 )
         {
            array<Char>^ temp0 = {'@','.',',','!'};
            if ( e->Label->IndexOfAny( temp0 ) == -1 )
            {
               
               // Stop editing without canceling the label change.
               e->Node->EndEdit( false );
            }
            else
            {
               /* Cancel the label edit action, inform the user, and 
                  place the node in edit mode again. */
               e->CancelEdit = true;
               MessageBox::Show( String::Concat( "Invalid tree node label.\n",
                  "The invalid characters are: '@','.', ',', '!'" ),
                  "Node Label Edit" );
               e->Node->BeginEdit();
            }
         }
         else
         {
            /* Cancel the label edit action, inform the user, and 
               place the node in edit mode again. */
            e->CancelEdit = true;
            MessageBox::Show( "Invalid tree node label.\nThe label cannot be blank",
               "Node Label Edit" );
            e->Node->BeginEdit();
         }
      }
   }

/* Get the tree node under the mouse pointer and
   save it in the mySelectedNode variable. */
private void treeView1_MouseDown(object sender,
  System.Windows.Forms.MouseEventArgs e)
{
   mySelectedNode = treeView1.GetNodeAt(e.X, e.Y);
}

private void menuItem1_Click(object sender, System.EventArgs e)
{
   if (mySelectedNode != null && mySelectedNode.Parent != null)
   {
      treeView1.SelectedNode = mySelectedNode;
      treeView1.LabelEdit = true;
      if(!mySelectedNode.IsEditing)
      {
         mySelectedNode.BeginEdit();
      }
   }
   else
   {
      MessageBox.Show("No tree node selected or selected node is a root node.\n" +
         "Editing of root nodes is not allowed.", "Invalid selection");
   }
}

private void treeView1_AfterLabelEdit(object sender,
         System.Windows.Forms.NodeLabelEditEventArgs e)
{
   if (e.Label != null)
   {
     if(e.Label.Length > 0)
     {
        if (e.Label.IndexOfAny(new char[]{'@', '.', ',', '!'}) == -1)
        {
           // Stop editing without canceling the label change.
           e.Node.EndEdit(false);
        }
        else
        {
           /* Cancel the label edit action, inform the user, and
              place the node in edit mode again. */
           e.CancelEdit = true;
           MessageBox.Show("Invalid tree node label.\n" +
              "The invalid characters are: '@','.', ',', '!'",
              "Node Label Edit");
           e.Node.BeginEdit();
        }
     }
     else
     {
        /* Cancel the label edit action, inform the user, and
           place the node in edit mode again. */
        e.CancelEdit = true;
        MessageBox.Show("Invalid tree node label.\nThe label cannot be blank",
           "Node Label Edit");
        e.Node.BeginEdit();
     }
   }
}

' Get the tree node under the mouse pointer and
' save it in the mySelectedNode variable. 
Private Sub treeView1_MouseDown(sender As Object, _
  e As System.Windows.Forms.MouseEventArgs)
        
   mySelectedNode = treeView1.GetNodeAt(e.X, e.Y)
End Sub    
    
Private Sub menuItem1_Click(sender As Object, e As System.EventArgs)
   If Not (mySelectedNode Is Nothing) And _
     Not (mySelectedNode.Parent Is Nothing) Then
      treeView1.SelectedNode = mySelectedNode
      treeView1.LabelEdit = True
      If Not mySelectedNode.IsEditing Then
         mySelectedNode.BeginEdit()
      End If
   Else
      MessageBox.Show("No tree node selected or selected node is a root node." & _
        Microsoft.VisualBasic.ControlChars.Cr & _
        "Editing of root nodes is not allowed.", "Invalid selection")
   End If
End Sub    
    
Private Sub treeView1_AfterLabelEdit(sender As Object, _
  e As System.Windows.Forms.NodeLabelEditEventArgs)
   If Not (e.Label Is Nothing) Then
      If e.Label.Length > 0 Then
         If e.Label.IndexOfAny(New Char() {"@"c, "."c, ","c, "!"c}) = -1 Then
            ' Stop editing without canceling the label change.
            e.Node.EndEdit(False)
         Else
            ' Cancel the label edit action, inform the user, and
            ' place the node in edit mode again. 
            e.CancelEdit = True
            MessageBox.Show("Invalid tree node label." & _
              Microsoft.VisualBasic.ControlChars.Cr & _
              "The invalid characters are: '@','.', ',', '!'", _
              "Node Label Edit")
            e.Node.BeginEdit()
         End If
      Else
         ' Cancel the label edit action, inform the user, and
         ' place the node in edit mode again. 
         e.CancelEdit = True
         MessageBox.Show("Invalid tree node label." & _
           Microsoft.VisualBasic.ControlChars.Cr & _
           "The label cannot be blank", "Node Label Edit")
           e.Node.BeginEdit()
      End If
   End If
End Sub

注解

可以将 事件的 和 MouseEventArgs.Y 坐标MouseDown作为 x 和 y 参数传递MouseEventArgs.X。

另请参阅

• Point