TreeViewDrawMode Enum

Reference

Definition

Namespace:: System.Windows.Forms

Assembly:: System.Windows.Forms.dll

Important

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Defines constants that represent the ways a TreeView can be drawn.

public enum class TreeViewDrawMode

public enum TreeViewDrawMode

type TreeViewDrawMode =

Public Enum TreeViewDrawMode

Inheritance: Object

ValueType

Enum
TreeViewDrawMode

Fields

Name	Value	Description
Normal	0	The TreeView is drawn by the operating system.
OwnerDrawText	1	The label portion of the TreeView nodes are drawn manually. Other node elements are drawn by the operating system, including icons, checkboxes, plus and minus signs, and lines connecting the nodes.
OwnerDrawAll	2	All elements of a TreeView node are drawn manually, including icons, checkboxes, plus and minus signs, and lines connecting the nodes.

Examples

The following code example demonstrates how to customize a TreeView control using its owner-draw capability. The TreeView control in the example displays optional node tags alongside the standard node labels. Node tags are specified using the TreeNode.Tag property. The TreeView control also uses custom colors, including a custom highlight color.

You can customize most of the TreeView colors by setting color properties, but the selection highlight color is not available as a property. Additionally, the default selection highlight rectangle extends only around a node label. Owner drawing must be used to draw the node tags and to draw a customized highlight rectangle large enough to include a node tag.

For the complete example, see the TreeView.DrawNode reference topic.

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

Remarks

This enumeration is used by the TreeView.DrawMode property to indicate whether the nodes or node-labels of a TreeView are owner-drawn. For more information, see the TreeView.DrawNode event.

Applies to

Delen via