TreeView.DrawMode 屬性

定義

命名空間:

System.Windows.Forms

組件:

System.Windows.Forms.dll

來源:

TreeView.cs

取得或設定控制的模式。

public:
 property System::Windows::Forms::TreeViewDrawMode DrawMode { System::Windows::Forms::TreeViewDrawMode get(); void set(System::Windows::Forms::TreeViewDrawMode value); };

public System.Windows.Forms.TreeViewDrawMode DrawMode { get; set; }

member this.DrawMode : System.Windows.Forms.TreeViewDrawMode with get, set

Public Property DrawMode As TreeViewDrawMode

屬性值

TreeViewDrawMode

這是其中一項 TreeViewDrawMode 價值。 預設值為 Normal。

例外狀況

InvalidEnumArgumentException

房產價值並不有效 TreeViewDrawMode 。

範例

以下程式碼範例示範如何利用擁有者繪圖來自訂控制項 TreeView 。 TreeView範例中的控制項會顯示可選的節點標籤，與標準節點標籤並列。 節點標籤是透過利用 屬性 TreeNode.Tag 來指定的。 TreeView控制鍵也使用自訂顏色，其中包含自訂的高亮色。

你可以透過設定顏色屬性來自訂大部分 TreeView 顏色，但選取高亮色作為屬性並不可使用。 此外，預設的選取矩形只延伸到節點標籤周圍。 必須使用擁有者繪圖來繪製節點標籤，並繪製一個足夠大的自訂高亮矩形以包含節點標籤。

完整範例請參見 DrawNode 參考主題。

TreeViewOwnerDraw()
{
   tagFont = gcnew System::Drawing::Font( "Helvetica",8,FontStyle::Bold );

   // Create and initialize the TreeView control.
   myTreeView = gcnew TreeView;
   myTreeView->Dock = DockStyle::Fill;
   myTreeView->BackColor = Color::Tan;
   myTreeView->CheckBoxes = true;
   
   // Add nodes to the TreeView control.
   TreeNode^ node;
   for ( int x = 1; x < 4; ++x )
   {
      // Add a root node to the TreeView control.
      node = myTreeView->Nodes->Add( String::Format( "Task {0}", x ) );
      for ( int y = 1; y < 4; ++y )
      {
         // Add a child node to the root node.
         node->Nodes->Add( String::Format( "Subtask {0}", y ) );
      }
   }
   myTreeView->ExpandAll();
   
   // Add tags containing alert messages to a few nodes 
   // and set the node background color to highlight them.
   myTreeView->Nodes[ 1 ]->Nodes[ 0 ]->Tag = "urgent!";
   myTreeView->Nodes[ 1 ]->Nodes[ 0 ]->BackColor = Color::Yellow;
   myTreeView->SelectedNode = myTreeView->Nodes[ 1 ]->Nodes[ 0 ];
   myTreeView->Nodes[ 2 ]->Nodes[ 1 ]->Tag = "urgent!";
   myTreeView->Nodes[ 2 ]->Nodes[ 1 ]->BackColor = Color::Yellow;
   
   // Configure the TreeView control for owner-draw and add
   // a handler for the DrawNode event.
   myTreeView->DrawMode = TreeViewDrawMode::OwnerDrawText;
   myTreeView->DrawNode += gcnew DrawTreeNodeEventHandler( this, &TreeViewOwnerDraw::myTreeView_DrawNode );
   
   // Add a handler for the MouseDown event so that a node can be 
   // selected by clicking the tag text as well as the node text.
   myTreeView->MouseDown += gcnew MouseEventHandler( this, &TreeViewOwnerDraw::myTreeView_MouseDown );
   
   // Initialize the form and add the TreeView control to it.
   this->ClientSize = System::Drawing::Size( 292, 273 );
   this->Controls->Add( myTreeView );
}

public TreeViewOwnerDraw()
{
    // Create and initialize the TreeView control.
    myTreeView = new TreeView();
    myTreeView.Dock = DockStyle.Fill;
    myTreeView.BackColor = Color.Tan;
    myTreeView.CheckBoxes = true;

    // Add nodes to the TreeView control.
    TreeNode node;
    for (int x = 1; x < 4; ++x)
    {
        // Add a root node to the TreeView control.
        node = myTreeView.Nodes.Add(String.Format("Task {0}", x));
        for (int y = 1; y < 4; ++y)
        {
            // Add a child node to the root node.
            node.Nodes.Add(String.Format("Subtask {0}", y));
        }
    }
    myTreeView.ExpandAll();

    // Add tags containing alert messages to a few nodes 
    // and set the node background color to highlight them.
    myTreeView.Nodes[1].Nodes[0].Tag = "urgent!";
    myTreeView.Nodes[1].Nodes[0].BackColor = Color.Yellow;
    myTreeView.SelectedNode = myTreeView.Nodes[1].Nodes[0];
    myTreeView.Nodes[2].Nodes[1].Tag = "urgent!";
    myTreeView.Nodes[2].Nodes[1].BackColor = Color.Yellow;

    // Configure the TreeView control for owner-draw and add
    // a handler for the DrawNode event.
    myTreeView.DrawMode = TreeViewDrawMode.OwnerDrawText;
    myTreeView.DrawNode += 
        new DrawTreeNodeEventHandler(myTreeView_DrawNode);

    // Add a handler for the MouseDown event so that a node can be 
    // selected by clicking the tag text as well as the node text.
    myTreeView.MouseDown += new MouseEventHandler(myTreeView_MouseDown);

    // Initialize the form and add the TreeView control to it.
    this.ClientSize = new Size(292, 273);
    this.Controls.Add(myTreeView);
}

Public Sub New()

    ' Create and initialize the TreeView control.
    myTreeView = New TreeView()
    myTreeView.Dock = DockStyle.Fill
    myTreeView.BackColor = Color.Tan
    myTreeView.CheckBoxes = True
    
    ' Add nodes to the TreeView control.
    Dim node As TreeNode
    Dim x As Integer
    For x = 1 To 3

        ' Add a root node to the TreeView control.
        node = myTreeView.Nodes.Add(String.Format("Task {0}", x))
        Dim y As Integer
        For y = 1 To 3 

            ' Add a child node to the root node.
            node.Nodes.Add(String.Format("Subtask {0}", y))
        Next y
    Next x
    myTreeView.ExpandAll()
    
    ' Add tags containing alert messages to a few nodes 
    ' and set the node background color to highlight them.
    myTreeView.Nodes(1).Nodes(0).Tag = "urgent!"
    myTreeView.Nodes(1).Nodes(0).BackColor = Color.Yellow
    myTreeView.SelectedNode = myTreeView.Nodes(1).Nodes(0)
    myTreeView.Nodes(2).Nodes(1).Tag = "urgent!"
    myTreeView.Nodes(2).Nodes(1).BackColor = Color.Yellow
    
    ' Configure the TreeView control for owner-draw.
    myTreeView.DrawMode = TreeViewDrawMode.OwnerDrawText

    ' Add a handler for the MouseDown event so that a node can be 
    ' selected by clicking the tag text as well as the node text.
    AddHandler myTreeView.MouseDown, AddressOf myTreeView_MouseDown
    
    ' Initialize the form and add the TreeView control to it.
    Me.ClientSize = New Size(292, 273)
    Me.Controls.Add(myTreeView)
End Sub

備註

a TreeView 的節點通常由作業系統繪製。 這個 DrawMode 屬性讓你可以自訂節點的外觀。 要做到這點，請設定 DrawMode 為 TreeViewDrawMode.OwnerDrawAll 或 TreeViewDrawMode.OwnerDrawText ，並提供事件的處理者 DrawNode 。 這稱為業主繪圖。

另請參閱

• TreeViewDrawMode
• DrawNode