TreeView.SelectedNode 属性

项目
08/17/2007

获取或设置当前在树视图控件中选定的树节点。

**命名空间:**System.Windows.Forms
**程序集:**System.Windows.Forms（在 system.windows.forms.dll 中）

语法

声明
Public Property SelectedNode As TreeNode
用法
Dim instance As TreeView
Dim value As TreeNode

value = instance.SelectedNode

instance.SelectedNode = value

public TreeNode SelectedNode { get; set; }

public:
property TreeNode^ SelectedNode {
    TreeNode^ get ();
    void set (TreeNode^ value);
}

/** @property */
public TreeNode get_SelectedNode ()

/** @property */
public void set_SelectedNode (TreeNode value)

public function get SelectedNode () : TreeNode

public function set SelectedNode (value : TreeNode)

属性值

当前在树视图控件中选定的 TreeNode。

备注

如果当前未选定任何 TreeNode，SelectedNode 属性则为空引用（在 Visual Basic 中为 Nothing）。

设置此属性时，指定的节点将滚入视图，所有父节点都将展开，使指定的节点可见。

当选定节点的父节点或任何祖先节点以编程方式或通过用户的操作折叠时，折叠的节点将成为选定的节点。

示例

下面的代码示例设置 TreeView 的 PathSeparator 属性，并显示 SelectedNode 的 TreeNodeCollection 中包含的子树节点数。还显示树视图控件中子树节点占全部树节点的百分比。本示例要求有一个包含 Button 的 Form 和一个包含 TreeNodeCollection 的 TreeView 控件，该集合包含若干个（最好是具有三级或三级以上的）TreeNode 对象。

Private Sub myButton_Click(ByVal sender As Object, _
  ByVal e As System.EventArgs) Handles myButton.Click
   ' Set the tre view's PathSeparator property.
   myTreeView.PathSeparator = "."

   ' Get the count of the child tree nodes contained in the SelectedNode.
   Dim myNodeCount As Integer = myTreeView.SelectedNode.GetNodeCount(True)
   Dim myChildPercentage As Decimal = CDec(myNodeCount) / _
      CDec(myTreeView.GetNodeCount(True)) * 100

   ' Display the tree node path and the number of child nodes it and the tree view have.
   MessageBox.Show(("The '" + myTreeView.SelectedNode.FullPath + "' node has " _
      + myNodeCount.ToString() + " child nodes." + Microsoft.VisualBasic.ControlChars.Lf _
      + "That is " + String.Format("{0:###.##}", myChildPercentage) _
      + "% of the total tree nodes in the tree view control."))
End Sub

private void myButton_Click(object sender, System.EventArgs e)
{
   // Set the tre view's PathSeparator property.
   myTreeView.PathSeparator = ".";

   // Get the count of the child tree nodes contained in the SelectedNode.
   int myNodeCount = myTreeView.SelectedNode.GetNodeCount(true);
   decimal myChildPercentage = ((decimal)myNodeCount/
     (decimal)myTreeView.GetNodeCount(true)) * 100;

   // Display the tree node path and the number of child nodes it and the tree view have.
   MessageBox.Show("The '" + myTreeView.SelectedNode.FullPath + "' node has " 
     + myNodeCount.ToString() + " child nodes.\nThat is " 
     + string.Format("{0:###.##}", myChildPercentage) 
     + "% of the total tree nodes in the tree view control.");
}

void myButton_Click( Object^ /*sender*/, System::EventArgs^ /*e*/ )
{
   
   // Set the tre view's PathSeparator property.
   myTreeView->PathSeparator = ".";
   
   // Get the count of the child tree nodes contained in the SelectedNode.
   int myNodeCount = myTreeView->SelectedNode->GetNodeCount( true );
   Decimal myChildPercentage = ((Decimal)myNodeCount / (Decimal)myTreeView->GetNodeCount( true )) * 100;
   
   // Display the tree node path and the number of child nodes it and the tree view have.
   MessageBox::Show( String::Concat( "The '", myTreeView->SelectedNode->FullPath, "' node has ", myNodeCount, " child nodes.\nThat is ", String::Format( "{0:###.##}", myChildPercentage ), "% of the total tree nodes in the tree view control." ) );
}

private void myButton_Click(Object sender, System.EventArgs e)
{
    // Set the tre view's PathSeparator property.
    myTreeView.set_PathSeparator(".");
    // Get the count of the child tree nodes contained in the SelectedNode.
    int myNodeCount = myTreeView.get_SelectedNode().GetNodeCount(true);
    System.Decimal myChildPercentage =
        Decimal.Multiply(Decimal.Divide(new Decimal(myNodeCount),
        new Decimal(myTreeView.GetNodeCount(true))), new Decimal(100));
    // Display the tree node path and the number of child nodes it and the
    // tree view have.
    MessageBox.Show("The '" + myTreeView.get_SelectedNode().get_FullPath()
        + "' node has " + ((Int32)myNodeCount).ToString()
        + " child nodes.\nThat is " + String.Format("{0:###.##}",
        myChildPercentage)
        + "% of the total tree nodes in the tree view control.");
} //myButton_Click

平台

Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Mobile for Smartphone、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition

.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。

TreeView.SelectedNode 属性

语法

属性值

备注

示例

平台

版本信息

.NET Framework

.NET Compact Framework

请参见

参考

其他资源