TreeView.DrawNode TreeView.DrawNode TreeView.DrawNode TreeView.DrawNode Event

정의

TreeView가 그려지고 DrawMode 속성이 Normal이 아닌 TreeViewDrawMode 값으로 설정되면 발생합니다.Occurs when a TreeView is drawn and the DrawMode property is set to a TreeViewDrawMode value other than Normal.

public:
 event System::Windows::Forms::DrawTreeNodeEventHandler ^ DrawNode;
public event System.Windows.Forms.DrawTreeNodeEventHandler DrawNode;
member this.DrawNode : System.Windows.Forms.DrawTreeNodeEventHandler 
Public Custom Event DrawNode As DrawTreeNodeEventHandler 

예제

다음 코드 예제에는 사용자 지정 하는 방법을 보여 줍니다.는 TreeView 소유자 그리기를 사용 하 여 제어 합니다.The following code example demonstrates how to customize a TreeView control using owner drawing. TreeView 예제에서 컨트롤 표준 노드 레이블와 함께 선택적 노드 태그를 표시 합니다.The TreeView control in the example displays optional node tags alongside the standard node labels. 노드 태그를 사용 하 여 지정 된 된 TreeNode.Tag 속성입니다.Node tags are specified by using the TreeNode.Tag property. TreeView 또한 사용 하 여 사용자 지정 강조 표시 색을 포함 하는 사용자 지정 색을 제어 합니다.The TreeView control also uses custom colors, which include a custom highlight color.

대부분의 사용자 지정할 수 있습니다는 TreeView 색 속성을 설정 하 여 색 있지만 선택 강조 색 속성으로 사용할 수 없습니다.You can customize most of the TreeView colors by setting color properties, but the selection highlight color is not available as a property. 또한 노드 레이블 주위에 기본 선택 항목 강조 표시 사각형을 확장합니다.Additionally, the default selection highlight rectangle extends only around a node label. 소유자 그리기는 노드 태그를 그릴 및 노드 태그를 포함 하도록 충분히 큰 사용자 지정된 강조 표시 사각형을 그리려면 사용 되어야 합니다.Owner drawing must be used to draw the node tags and to draw a customized highlight rectangle large enough to include a node tag.

예에 대 한 처리기를 DrawNode 노드 태그 및 사용자 지정 선택 수동으로 강조 표시 하는 이벤트 그립니다.In the example, a handler for the DrawNode event draws the node tags and the custom selection highlight manually. 선택 되지 않은 노드는 사용자 지정할이 필요가 없습니다.Unselected nodes do not need customization. 이러한 경우는 DrawTreeNodeEventArgs.DrawDefault 속성이 true 운영 체제에서 그려질 수 있도록 합니다.For these, the DrawTreeNodeEventArgs.DrawDefault property is set to true so that they will be drawn by the operating system.

또한 처리기는 MouseDown 이벤트 적중 테스트를 제공 합니다.Additionally, a handler for the MouseDown event provides hit-testing. 기본적으로 노드는 레이블 주위의 영역을 클릭 해 서만 선택할 수 있습니다.By default, a node can be selected only by clicking the region around its label. MouseDown 이벤트 처리기는 있는 경우이 지역 내에서 또는 노드 태그 주변 지역 내에서 아무 곳 이나 클릭 되는 노드를 선택 합니다.The MouseDown event handler selects a node that is clicked anywhere within this region or within the region around a node tag, if present.

#using <System.dll>
#using <System.Windows.Forms.dll>
#using <System.Drawing.dll>

using namespace System;
using namespace System::Drawing;
using namespace System::Windows::Forms;
public ref class TreeViewOwnerDraw: public Form
{
private:
   TreeView^ myTreeView;

   // Create a Font object for the node tags.
   System::Drawing::Font^ tagFont;

public:

   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 );
   }

protected:
   // Clean up any resources being used.        
   ~TreeViewOwnerDraw()
   {
      if ( tagFont != nullptr )
      {
         delete tagFont;
      }
   }

   // Draws a node.
private:
   void myTreeView_DrawNode( Object^ sender, DrawTreeNodeEventArgs^ e )
   {
      // Draw the background and node text for a selected node.
      if ( (e->State & TreeNodeStates::Selected) != (TreeNodeStates)0 )
      {
         // Draw the background of the selected node. The NodeBounds
         // method makes the highlight rectangle large enough to
         // include the text of a node tag, if one is present.
         e->Graphics->FillRectangle( Brushes::Green, NodeBounds( e->Node ) );

         // Retrieve the node font. If the node font has not been set,
         // use the TreeView font.
         System::Drawing::Font^ nodeFont = e->Node->NodeFont;
         if ( nodeFont == nullptr )
                  nodeFont = (dynamic_cast<TreeView^>(sender))->Font;

         // Draw the node text.
         e->Graphics->DrawString( e->Node->Text, nodeFont, Brushes::White, Rectangle::Inflate( e->Bounds, 2, 0 ) );
      }
      // Use the default background and node text.
      else
      {
         e->DrawDefault = true;
      }

      // If a node tag is present, draw its string representation 
      // to the right of the label text.
      if ( e->Node->Tag != nullptr )
      {
         e->Graphics->DrawString( e->Node->Tag->ToString(), tagFont, Brushes::Yellow, (float)e->Bounds.Right + 2, (float)e->Bounds.Top );
      }

      
      // If the node has focus, draw the focus rectangle large, making
      // it large enough to include the text of the node tag, if present.
      if ( (e->State & TreeNodeStates::Focused) != (TreeNodeStates)0 )
      {
         Pen^ focusPen = gcnew Pen( Color::Black );
         try
         {
            focusPen->DashStyle = System::Drawing::Drawing2D::DashStyle::Dot;
            Rectangle focusBounds = NodeBounds( e->Node );
            focusBounds.Size = System::Drawing::Size( focusBounds.Width - 1, focusBounds.Height - 1 );
            e->Graphics->DrawRectangle( focusPen, focusBounds );
         }
         finally
         {
            if ( focusPen )
               delete safe_cast<IDisposable^>(focusPen);
         }

      }
   }

   // Selects a node that is clicked on its label or tag text.
   void myTreeView_MouseDown( Object^ /*sender*/, MouseEventArgs^ e )
   {
      TreeNode^ clickedNode = myTreeView->GetNodeAt( e->X, e->Y );
      if ( NodeBounds( clickedNode ).Contains( e->X, e->Y ) )
      {
         myTreeView->SelectedNode = clickedNode;
      }
   }

   // Returns the bounds of the specified node, including the region 
   // occupied by the node label and any node tag displayed.
   Rectangle NodeBounds( TreeNode^ node )
   {
      // Set the return value to the normal node bounds.
      Rectangle bounds = node->Bounds;
      if ( node->Tag != nullptr )
      {
         // Retrieve a Graphics object from the TreeView handle
         // and use it to calculate the display width of the tag.
         Graphics^ g = myTreeView->CreateGraphics();
         int tagWidth = (int)g->MeasureString( node->Tag->ToString(), tagFont ).Width + 6;
         
         // Adjust the node bounds using the calculated value.
         bounds.Offset( tagWidth / 2, 0 );
         bounds = Rectangle::Inflate( bounds, tagWidth / 2, 0 );
         g->~Graphics();
      }

      return bounds;
   }
};

[STAThreadAttribute]
int main()
{
   Application::Run( gcnew TreeViewOwnerDraw );
}
using System;
using System.Drawing;
using System.Windows.Forms;

public class TreeViewOwnerDraw : Form
{
    private TreeView myTreeView;

    // Create a Font object for the node tags.
    Font tagFont = new Font("Helvetica", 8, FontStyle.Bold);

    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);
    }

    // Clean up any resources being used.        
    protected override void Dispose(bool disposing)
    {
        if (disposing)
        {
            tagFont.Dispose();
        }
        base.Dispose(disposing);
    }

    [STAThreadAttribute()]
    static void Main() 
    {
        Application.Run(new TreeViewOwnerDraw());
    }

    // Draws a node.
    private void myTreeView_DrawNode(
        object sender, DrawTreeNodeEventArgs e)
    {
        // Draw the background and node text for a selected node.
        if ((e.State & TreeNodeStates.Selected) != 0)
        {
            // Draw the background of the selected node. The NodeBounds
            // method makes the highlight rectangle large enough to
            // include the text of a node tag, if one is present.
            e.Graphics.FillRectangle(Brushes.Green, NodeBounds(e.Node));

            // Retrieve the node font. If the node font has not been set,
            // use the TreeView font.
            Font nodeFont = e.Node.NodeFont;
            if (nodeFont == null) nodeFont = ((TreeView)sender).Font;

            // Draw the node text.
            e.Graphics.DrawString(e.Node.Text, nodeFont, Brushes.White,
                Rectangle.Inflate(e.Bounds, 2, 0));
        }

        // Use the default background and node text.
        else 
        {
            e.DrawDefault = true;
        }

        // If a node tag is present, draw its string representation 
        // to the right of the label text.
        if (e.Node.Tag != null)
        {
            e.Graphics.DrawString(e.Node.Tag.ToString(), tagFont,
                Brushes.Yellow, e.Bounds.Right + 2, e.Bounds.Top);
        }

        // If the node has focus, draw the focus rectangle large, making
        // it large enough to include the text of the node tag, if present.
        if ((e.State & TreeNodeStates.Focused) != 0)
        {
            using (Pen focusPen = new Pen(Color.Black))
            {
                focusPen.DashStyle = System.Drawing.Drawing2D.DashStyle.Dot;
                Rectangle focusBounds = NodeBounds(e.Node);
                focusBounds.Size = new Size(focusBounds.Width - 1, 
                focusBounds.Height - 1);
                e.Graphics.DrawRectangle(focusPen, focusBounds);
            }
        }
    }

    // Selects a node that is clicked on its label or tag text.
    private void myTreeView_MouseDown(object sender, MouseEventArgs e)
    {
        TreeNode clickedNode = myTreeView.GetNodeAt(e.X, e.Y);
        if (NodeBounds(clickedNode).Contains(e.X, e.Y))
        {
            myTreeView.SelectedNode = clickedNode;
        }
    }

    // Returns the bounds of the specified node, including the region 
    // occupied by the node label and any node tag displayed.
    private Rectangle NodeBounds(TreeNode node)
    {
        // Set the return value to the normal node bounds.
        Rectangle bounds = node.Bounds;
        if (node.Tag != null)
        {
            // Retrieve a Graphics object from the TreeView handle
            // and use it to calculate the display width of the tag.
            Graphics g = myTreeView.CreateGraphics(); 
            int tagWidth = (int)g.MeasureString
                (node.Tag.ToString(), tagFont).Width + 6;

            // Adjust the node bounds using the calculated value.
            bounds.Offset(tagWidth/2, 0);
            bounds = Rectangle.Inflate(bounds, tagWidth/2, 0);
            g.Dispose();
         }
        
        return bounds;
        
    }

}
Imports System.Drawing
Imports System.Windows.Forms

Public Class TreeViewOwnerDraw
    Inherits Form

    Private WithEvents myTreeView As TreeView
    
    ' Create a Font object for the node tags.
    Private tagFont As New Font("Helvetica", 8, FontStyle.Bold)
    
    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 'New
    
    <STAThreadAttribute()> _
    Shared Sub Main()
        Application.Run(New TreeViewOwnerDraw())
    End Sub 'Main
    
    ' Draws a node.
    Private Sub myTreeView_DrawNode(ByVal sender As Object, _
        ByVal e As DrawTreeNodeEventArgs) Handles myTreeView.DrawNode

        ' Draw the background and node text for a selected node.
        If (e.State And TreeNodeStates.Selected) <> 0 Then

            ' Draw the background of the selected node. The NodeBounds
            ' method makes the highlight rectangle large enough to
            ' include the text of a node tag, if one is present.
            e.Graphics.FillRectangle(Brushes.Green, NodeBounds(e.Node))

            ' Retrieve the node font. If the node font has not been set,
            ' use the TreeView font.
            Dim nodeFont As Font = e.Node.NodeFont
            If nodeFont Is Nothing Then
                nodeFont = CType(sender, TreeView).Font
            End If

            ' Draw the node text.
            e.Graphics.DrawString(e.Node.Text, nodeFont, Brushes.White, _
                e.Bounds.Left - 2, e.Bounds.Top)

        ' Use the default background and node text.
        Else
            e.DrawDefault = True
        End If

        ' If a node tag is present, draw its string representation 
        ' to the right of the label text.
        If (e.Node.Tag IsNot Nothing) Then
            e.Graphics.DrawString(e.Node.Tag.ToString(), tagFont, _
                Brushes.Yellow, e.Bounds.Right + 2, e.Bounds.Top)
        End If

        ' If the node has focus, draw the focus rectangle large, making
        ' it large enough to include the text of the node tag, if present.
        If (e.State And TreeNodeStates.Focused) <> 0 Then
            Dim focusPen As New Pen(Color.Black)
            Try
                focusPen.DashStyle = System.Drawing.Drawing2D.DashStyle.Dot
                Dim focusBounds As Rectangle = NodeBounds(e.Node)
                focusBounds.Size = New Size(focusBounds.Width - 1, _
                    focusBounds.Height - 1)
                e.Graphics.DrawRectangle(focusPen, focusBounds)
            Finally
                focusPen.Dispose()
            End Try
        End If

    End Sub 'myTreeView_DrawNode

    ' Selects a node that is clicked on its label or tag text.
    Private Sub myTreeView_MouseDown(ByVal sender As Object, ByVal e As MouseEventArgs)
        Dim clickedNode As TreeNode = myTreeView.GetNodeAt(e.X, e.Y)
        If NodeBounds(clickedNode).Contains(e.X, e.Y) Then
            myTreeView.SelectedNode = clickedNode
        End If
    End Sub 'myTreeView_MouseDown

    ' Returns the bounds of the specified node, including the region 
    ' occupied by the node label and any node tag displayed.
    Private Function NodeBounds(ByVal node As TreeNode) As Rectangle

        ' Set the return value to the normal node bounds.
        Dim bounds As Rectangle = node.Bounds
        If (node.Tag IsNot Nothing) Then

            ' Retrieve a Graphics object from the TreeView handle
            ' and use it to calculate the display width of the tag.
            Dim g As Graphics = myTreeView.CreateGraphics()
            Dim tagWidth As Integer = CInt(g.MeasureString( _
                node.Tag.ToString(), tagFont).Width) + 6

            ' Adjust the node bounds using the calculated value.
            bounds.Offset(tagWidth \ 2, 0)
            bounds = Rectangle.Inflate(bounds, tagWidth \ 2, 0)
            g.Dispose()
        End If
        Return bounds
    End Function 'NodeBounds

End Class 'TreeViewOwnerDraw 

설명

이 이벤트를 사용 하 여 노드의 모양을 사용자 지정 하는 TreeView 소유자 그리기를 사용 하 여 제어 합니다.Use this event to customize the appearance of nodes in a TreeView control using owner drawing.

이 이벤트는 경우에만 합니다 DrawMode 속성이 TreeViewDrawMode 의 값 OwnerDrawAll 또는 OwnerDrawText합니다.This event is raised only when the DrawMode property is set to TreeViewDrawMode values of OwnerDrawAll or OwnerDrawText. 다음 표에서 하는 방법을 TreeNode 경우 사용자 지정할 수 있습니다는 DrawMode 이러한 값을 설정 합니다.The following table indicates how the TreeNode can be customized when the DrawMode property is set to these values.

DrawMode 속성 값DrawMode property value TreeNode 사용자 지정TreeNode customization
OwnerDrawText TreeNode 레이블 영역을 사용자 지정할 수 있습니다.The TreeNode label area can be customized. 다른 모든 TreeNode 요소는 자동으로 그려집니다.All other TreeNode elements are drawn automatically.
OwnerDrawAll 전체 모양의 TreeNode 사용자 지정할 수 있습니다.The appearance of the entire TreeNode can be customized. 아이콘, 확인란, 더하기 및 빼기 기호 및 노드를 연결 하는 선을 그려야 수동으로 필요한 경우.Icons, check boxes, plus and minus signs, and lines connecting the nodes must be drawn manually if they are desired.

지역은를 TreeNode.Text 값이 지정 된 글꼴을 사용 하 여 그린 경우 차지 합니다 TreeView 컨트롤의 Font 속성은 선택 하는 노드를 클릭할 수는 지역입니다.The region that the TreeNode.Text value would occupy if it were drawn using the font specified by the TreeView control's Font property is the region in which a node can be clicked to select it. 이 적중된 테스트 영역을 이라고 합니다.This is called the hit test region. 이 영역 밖에 그릴 경우 해당 표시 영역을 클릭할 때 노드를 선택 하는 사용자 고유의 코드를 제공 해야 합니다.If you draw outside this region, you should provide your own code that selects a node when its visible area is clicked.

적중된 테스트 영역에 해당 하는 DrawTreeNodeEventArgs.Bounds 사용 하는 경우 속성 OwnerDrawText합니다.The hit test region corresponds to the DrawTreeNodeEventArgs.Bounds property when using OwnerDrawText. 사용 하는 경우 OwnerDrawAll그러나 합니다 DrawTreeNodeEventArgs.Bounds 속성의 전체 너비를 포함 합니다 TreeView합니다.When using OwnerDrawAll, however, the DrawTreeNodeEventArgs.Bounds property encompasses the entire width of the TreeView. 이 경우 시작 하 여 적중된 테스트 영역에 액세스할 수 있습니다는 DrawTreeNodeEventArgs.Node 값에 액세스 하 고 해당 TreeNode.Bounds 속성입니다.In this case, you can access the hit test region by getting the DrawTreeNodeEventArgs.Node value and accessing its TreeNode.Bounds property. 이러한 범위 내에서 노드의 적중 횟수 테스트 영역을 그릴 수 있습니다 또는 사용자 고유의 적중된 테스트 코드를 제공할 수 있습니다.You can then draw the hit test region of the node within these bounds, or you can provide your own hit test code. 설정 합니다 TreeNode.NodeFont 속성이 지정 된 글꼴을 사용 하 여 전체에 대해 계산 되는 적중된 테스트 영역의 크기를 변경 되지 않습니다 TreeView합니다.Note that setting the TreeNode.NodeFont property does not change the size of the hit test region, which is calculated using the font specified for the entire TreeView.

이벤트를 처리 하는 방법에 대 한 자세한 내용은 참조 하세요. 이벤트 처리 및 발생합니다.For more information about how to handle events, see Handling and Raising Events.

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