DrawToolTipEventHandler DrawToolTipEventHandler DrawToolTipEventHandler DrawToolTipEventHandler Delegate

定义

表示将用来处理 DrawToolTip 事件的方法。Represents the method that will handle the Draw event of a ToolTip.

public delegate void DrawToolTipEventHandler(System::Object ^ sender, DrawToolTipEventArgs ^ e);
public delegate void DrawToolTipEventHandler(object sender, DrawToolTipEventArgs e);
type DrawToolTipEventHandler = delegate of obj * DrawToolTipEventArgs -> unit
Public Delegate Sub DrawToolTipEventHandler(sender As Object, e As DrawToolTipEventArgs)

参数

sender
Object Object Object Object

事件源。The source of the event.

继承
DrawToolTipEventHandlerDrawToolTipEventHandlerDrawToolTipEventHandlerDrawToolTipEventHandler

示例

下面的代码示例演示如何自定义绘制ToolTipThe following code example demonstrates how to custom draw the ToolTip. 此示例将创建ToolTip并将其关联到三个Button控件位于FormThe example creates a ToolTip and associates it to three Button controls located on the Form. 该示例设置OwnerDraw属性为 true,并且句柄Draw事件。The example sets the OwnerDraw property to true and handles the Draw event. 在中Draw事件处理程序ToolTip的自定义绘制以不同的方式取决于哪个按钮ToolTip所示为其显示的DrawToolTipEventArgs.AssociatedControl属性。In the Draw event handler, the ToolTip is custom drawn differently depending upon what button the ToolTip is being displayed for as indicated by the DrawToolTipEventArgs.AssociatedControl property.

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

using namespace System;
using namespace System::Drawing;
using namespace System::Windows::Forms;
using namespace System::Windows::Forms::VisualStyles;

// Form for the ToolTip example.
public ref class ToolTipExampleForm: public System::Windows::Forms::Form
{
private:
   System::Windows::Forms::ToolTip^ toolTip1;
   System::Windows::Forms::Button^ button1;
   System::Windows::Forms::Button^ button2;
   System::Windows::Forms::Button^ button3;

public:
   ToolTipExampleForm()
   {
      // Create the ToolTip and set initial values.
      this->toolTip1 = gcnew System::Windows::Forms::ToolTip;
      this->toolTip1->AutoPopDelay = 5000;
      this->toolTip1->InitialDelay = 500;
      this->toolTip1->OwnerDraw = true;
      this->toolTip1->ReshowDelay = 10;
      this->toolTip1->Draw += gcnew DrawToolTipEventHandler( this, &ToolTipExampleForm::toolTip1_Draw );
      
      // Create button1 and set initial values.
      this->button1 = gcnew System::Windows::Forms::Button;
      this->button1->Location = System::Drawing::Point( 8, 8 );
      this->button1->Text = "Button 1";
      this->toolTip1->SetToolTip( this->button1, "Button1 tip text" );
      
      // Create button2 and set initial values.
      this->button2 = gcnew System::Windows::Forms::Button;
      this->button2->Location = System::Drawing::Point( 8, 32 );
      this->button2->Text = "Button 2";
      this->toolTip1->SetToolTip( this->button2, "Button2 tip text" );
      
      // Create button3 and set initial values.
      this->button3 = gcnew System::Windows::Forms::Button;
      this->button3->Location = System::Drawing::Point( 8, 56 );
      this->button3->Text = "Button 3";
      this->toolTip1->SetToolTip( this->button3, "Button3 tip text" );
      
      // Set up the Form.
      array<Control^>^temp0 = {this->button1,this->button2,this->button3};
      this->Controls->AddRange( temp0 );
      this->Text = "owner drawn ToolTip example";
   }

protected:

   ~ToolTipExampleForm()
   {
      if ( toolTip1 != nullptr )
      {
         delete toolTip1;
      }
   }

   // Handles drawing the ToolTip.
private:
   void toolTip1_Draw( System::Object^ /*sender*/, System::Windows::Forms::DrawToolTipEventArgs^ e )
   {
      // Draw the ToolTip differently depending on which 
      // control this ToolTip is for.
      // Draw a custom 3D border if the ToolTip is for button1.
      if ( e->AssociatedControl == button1 )
      {
         // Draw the standard background.
         e->DrawBackground();
         
         // Draw the custom border to appear 3-dimensional.
         array<Point>^ temp1 = {Point(0,e->Bounds.Height - 1),Point(0,0),Point(e->Bounds.Width - 1,0)};
         e->Graphics->DrawLines( SystemPens::ControlLightLight, temp1 );
         array<Point>^ temp2 = {Point(0,e->Bounds.Height - 1),Point(e->Bounds.Width - 1,e->Bounds.Height - 1),Point(e->Bounds.Width - 1,0)};
         e->Graphics->DrawLines( SystemPens::ControlDarkDark, temp2 );
         
         // Specify custom text formatting flags.
         TextFormatFlags sf = static_cast<TextFormatFlags>(TextFormatFlags::VerticalCenter | TextFormatFlags::HorizontalCenter | TextFormatFlags::NoFullWidthCharacterBreak);
         
         // Draw the standard text with customized formatting options.
         e->DrawText( sf );
      }
      // Draw a custom background and text if the ToolTip is for button2.
      else
      
      // Draw a custom background and text if the ToolTip is for button2.
      if ( e->AssociatedControl == button2 )
      {
         // Draw the custom background.
         e->Graphics->FillRectangle( SystemBrushes::ActiveCaption, e->Bounds );
         
         // Draw the standard border.
         e->DrawBorder();
         
         // Draw the custom text.
         // The using block will dispose the StringFormat automatically.
         StringFormat^ sf = gcnew StringFormat;
         try
         {
            sf->Alignment = StringAlignment::Center;
            sf->LineAlignment = StringAlignment::Center;
            sf->HotkeyPrefix = System::Drawing::Text::HotkeyPrefix::None;
            sf->FormatFlags = StringFormatFlags::NoWrap;
            System::Drawing::Font^ f = gcnew System::Drawing::Font( "Tahoma",9 );
            try
            {
               e->Graphics->DrawString( e->ToolTipText, f, SystemBrushes::ActiveCaptionText, e->Bounds, sf );
            }
            finally
            {
               if ( f )
                  delete safe_cast<IDisposable^>(f);
            }

         }
         finally
         {
            if ( sf )
               delete safe_cast<IDisposable^>(sf);
         }
      }
      // Draw the ToolTip using default values if the ToolTip is for button3.
      else if ( e->AssociatedControl == button3 )
      {
         e->DrawBackground();
         e->DrawBorder();
         e->DrawText();
      }
   }
};

// The main entry point for the application.

[STAThread]
int main()
{
   Application::Run( gcnew ToolTipExampleForm );
}
using System;
using System.Drawing;
using System.Windows.Forms;
using System.Windows.Forms.VisualStyles;

namespace ToolTipExample
{
    // Form for the ToolTip example.
    public class ToolTipExampleForm : System.Windows.Forms.Form
    {
        private System.Windows.Forms.ToolTip toolTip1;
        private System.Windows.Forms.Button button1;
        private System.Windows.Forms.Button button2;
        private System.Windows.Forms.Button button3;

        public ToolTipExampleForm()
        {
            // Create the ToolTip and set initial values.
            this.toolTip1 = new System.Windows.Forms.ToolTip();
            this.toolTip1.AutoPopDelay = 5000;
            this.toolTip1.InitialDelay = 500;
            this.toolTip1.OwnerDraw = true;
            this.toolTip1.ReshowDelay = 10;
            this.toolTip1.Draw += new DrawToolTipEventHandler(this.toolTip1_Draw);
            this.toolTip1.Popup += new PopupEventHandler(toolTip1_Popup);

            // Create button1 and set initial values.
            this.button1 = new System.Windows.Forms.Button();
            this.button1.Location = new System.Drawing.Point(8, 8);
            this.button1.Text = "Button 1";
            this.toolTip1.SetToolTip(this.button1, "Button1 tip text");

            // Create button2 and set initial values.
            this.button2 = new System.Windows.Forms.Button();
            this.button2.Location = new System.Drawing.Point(8, 32);
            this.button2.Text = "Button 2";
            this.toolTip1.SetToolTip(this.button2, "Button2 tip text");

            // Create button3 and set initial values.
            this.button3 = new System.Windows.Forms.Button();
            this.button3.Location = new System.Drawing.Point(8, 56);
            this.button3.Text = "Button 3";
            this.toolTip1.SetToolTip(this.button3, "Button3 tip text");

            // Set up the Form.
            this.Controls.AddRange(new Control[] {
                this.button1, this.button2, this.button3
            });
            this.Text = "owner drawn ToolTip example";
        }

        // Clean up any resources being used.        
        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                toolTip1.Dispose();
            }

            base.Dispose(disposing);
        }

        // The main entry point for the application.
        [STAThread]
        static void Main()
        {
            Application.Run(new ToolTipExampleForm());
        }

        // Determines the correct size for the button2 ToolTip.
        private void toolTip1_Popup(object sender, PopupEventArgs e)
        {
            if (e.AssociatedControl == button2)
            {
                using (Font f = new Font("Tahoma", 9))
                {
                    e.ToolTipSize = TextRenderer.MeasureText(
                        toolTip1.GetToolTip(e.AssociatedControl), f);
                }
            }
        }

        // Handles drawing the ToolTip.
        private void toolTip1_Draw(System.Object sender, 
            System.Windows.Forms.DrawToolTipEventArgs e)
        {
            // Draw the ToolTip differently depending on which 
            // control this ToolTip is for.
            // Draw a custom 3D border if the ToolTip is for button1.
            if (e.AssociatedControl == button1)
            {
                // Draw the standard background.
                e.DrawBackground();

                // Draw the custom border to appear 3-dimensional.
                e.Graphics.DrawLines(SystemPens.ControlLightLight, new Point[] {
                    new Point (0, e.Bounds.Height - 1), 
                    new Point (0, 0), 
                    new Point (e.Bounds.Width - 1, 0)
                });
                e.Graphics.DrawLines(SystemPens.ControlDarkDark, new Point[] {
                    new Point (0, e.Bounds.Height - 1), 
                    new Point (e.Bounds.Width - 1, e.Bounds.Height - 1), 
                    new Point (e.Bounds.Width - 1, 0)
                });

                // Specify custom text formatting flags.
                TextFormatFlags sf = TextFormatFlags.VerticalCenter |
                                     TextFormatFlags.HorizontalCenter |
                                     TextFormatFlags.NoFullWidthCharacterBreak;

                // Draw the standard text with customized formatting options.
                e.DrawText(sf);
            }
            // Draw a custom background and text if the ToolTip is for button2.
            else if (e.AssociatedControl == button2)
            {
                // Draw the custom background.
                e.Graphics.FillRectangle(SystemBrushes.ActiveCaption, e.Bounds);

                // Draw the standard border.
                e.DrawBorder();

                // Draw the custom text.
                // The using block will dispose the StringFormat automatically.
                using (StringFormat sf = new StringFormat())
                {
                    sf.Alignment = StringAlignment.Center;
                    sf.LineAlignment = StringAlignment.Center;
                    sf.HotkeyPrefix = System.Drawing.Text.HotkeyPrefix.None;
                    sf.FormatFlags = StringFormatFlags.NoWrap;
                    using (Font f = new Font("Tahoma", 9))
                    {
                        e.Graphics.DrawString(e.ToolTipText, f, 
                            SystemBrushes.ActiveCaptionText, e.Bounds, sf);
                    }
                }
            }
            // Draw the ToolTip using default values if the ToolTip is for button3.
            else if (e.AssociatedControl == button3)
            {
                e.DrawBackground();
                e.DrawBorder();
                e.DrawText();
            }
        }
    }
}
Imports System
Imports System.Drawing
Imports System.Windows.Forms
Imports System.Windows.Forms.VisualStyles

Public Module ToolTipExampleApp
    ' The main entry point for the application.
    <STAThread()> _
    Sub Main()
        Application.Run(New ToolTipExampleForm)
    End Sub
End Module

' Form for the ToolTip example.
Public Class ToolTipExampleForm
    Inherits System.Windows.Forms.Form

    Private WithEvents toolTip1 As System.Windows.Forms.ToolTip
    Private WithEvents button1 As System.Windows.Forms.Button
    Private WithEvents button2 As System.Windows.Forms.Button
    Private WithEvents button3 As System.Windows.Forms.Button

    Public Sub New()
        ' Create the ToolTip and set initial values.
        Me.toolTip1 = New System.Windows.Forms.ToolTip
        Me.toolTip1.AutoPopDelay = 5000
        Me.toolTip1.InitialDelay = 500
        Me.toolTip1.OwnerDraw = True
        Me.toolTip1.ReshowDelay = 10

        ' Create button1 and set initial values.
        Me.button1 = New System.Windows.Forms.Button
        Me.button1.Location = New System.Drawing.Point(8, 8)
        Me.button1.Text = "Button 1"
        Me.toolTip1.SetToolTip(Me.button1, "Button1 tip text")

        ' Create button2 and set initial values.
        Me.button2 = New System.Windows.Forms.Button
        Me.button2.Location = New System.Drawing.Point(8, 32)
        Me.button2.Text = "Button 2"
        Me.toolTip1.SetToolTip(Me.button2, "Button2 tip text")

        ' Create button3 and set initial values.
        Me.button3 = New System.Windows.Forms.Button
        Me.button3.Location = New System.Drawing.Point(8, 56)
        Me.button3.Text = "Button 3"
        Me.toolTip1.SetToolTip(Me.button3, "Button3 tip text")

        ' Set up the Form.
        Me.Controls.AddRange(New Control() {Me.button1, _
                                            Me.button2, _
                                            Me.button3})
        Me.Text = "owner drawn ToolTip example"
    End Sub

    ' Clean up any resources being used.        
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If (disposing) Then
            toolTip1.Dispose()
        End If

        MyBase.Dispose(disposing)
    End Sub

    ' Determines the correct size for the button2 ToolTip.
    Private Sub toolTip1_Popup(ByVal sender As System.Object, _
        ByVal e As PopupEventArgs) Handles toolTip1.Popup

        If e.AssociatedControl Is button2 Then

            Dim f As New Font("Tahoma", 9)
            Try
                e.ToolTipSize = TextRenderer.MeasureText( _
                    toolTip1.GetToolTip(e.AssociatedControl), f)
            Finally
                f.Dispose()
            End Try

        End If
    End Sub

    ' Handles drawing the ToolTip.
    Private Sub toolTip1_Draw(ByVal sender As System.Object, _
        ByVal e As DrawToolTipEventArgs) Handles toolTip1.Draw
        ' Draw the ToolTip differently depending on which 
        ' control this ToolTip is for.

        ' Draw a custom 3D border if the ToolTip is for button1.
        If (e.AssociatedControl Is button1) Then
            ' Draw the standard background.
            e.DrawBackground()

            ' Draw the custom border to appear 3-dimensional.
            e.Graphics.DrawLines( _
                SystemPens.ControlLightLight, New Point() { _
                New Point(0, e.Bounds.Height - 1), _
                New Point(0, 0), _
                New Point(e.Bounds.Width - 1, 0)})
            e.Graphics.DrawLines( _
                SystemPens.ControlDarkDark, New Point() { _
                New Point(0, e.Bounds.Height - 1), _
                New Point(e.Bounds.Width - 1, e.Bounds.Height - 1), _
                New Point(e.Bounds.Width - 1, 0)})

            ' Specify custom text formatting flags.
            Dim sf As TextFormatFlags = TextFormatFlags.VerticalCenter Or _
                                 TextFormatFlags.HorizontalCenter Or _
                                 TextFormatFlags.NoFullWidthCharacterBreak

            ' Draw standard text with customized formatting options.
            e.DrawText(sf)
        ElseIf (e.AssociatedControl Is button2) Then
            ' Draw a custom background and text if the ToolTip is for button2.

            ' Draw the custom background.
            e.Graphics.FillRectangle(SystemBrushes.ActiveCaption, e.Bounds)

            ' Draw the standard border.
            e.DrawBorder()

            ' Draw the custom text.
            Dim sf As StringFormat = New StringFormat
            Try
                sf.Alignment = StringAlignment.Center
                sf.LineAlignment = StringAlignment.Center
                sf.HotkeyPrefix = System.Drawing.Text.HotkeyPrefix.None
                sf.FormatFlags = StringFormatFlags.NoWrap

                Dim f As Font = New Font("Tahoma", 9)
                Try
                    e.Graphics.DrawString(e.ToolTipText, f, _
                        SystemBrushes.ActiveCaptionText, _
                        RectangleF.op_Implicit(e.Bounds), sf)
                Finally
                    f.Dispose()
                End Try
            Finally
                sf.Dispose()
            End Try
        ElseIf (e.AssociatedControl Is button3) Then
            ' Draw the ToolTip using default values if the ToolTip is for button3.
            e.DrawBackground()
            e.DrawBorder()
            e.DrawText()
        End If
    End Sub
End Class

注解

ToolTip.Draw引发事件ToolTip类时ToolTip绘制和ToolTip.OwnerDraw属性值是trueThe ToolTip.Draw event is raised by the ToolTip class when the ToolTip is drawn and the ToolTip.OwnerDraw property value is true. DrawToolTipEventArgs类包含要绘制所需的所有信息ToolTip,其中包括的工具提示文本, Rectangle,和Graphics上完成绘图对象中。The DrawToolTipEventArgs class contains all the information needed to paint the ToolTip, including the ToolTip text, the Rectangle, and the Graphics object on which the drawing should be done. 若要自定义工具提示的外观,请使用Rectangle来确定在工具提示的边界和Graphics对象以执行自定义的绘制。To customize the look of the ToolTip, use the Rectangle to determine the bounds of the ToolTip, and the Graphics object to perform your customized drawing. 您可以增加的边界ToolTip情况下处理显示之前Popup事件。You can increase the bounds of the ToolTip before it is shown by handling the Popup event.

创建 DrawToolTipEventHandler 委托时,需要标识将处理该事件的方法。When you create a DrawToolTipEventHandler delegate, you identify the method that will handle the event. 若要将事件与事件处理程序关联,请将该委托的一个实例添加到事件中。To associate the event with your event handler, add an instance of the delegate to the event. 除非移除了该委托,否则每当发生该事件时就会调用事件处理程序。The event handler is called whenever the event occurs, unless you remove the delegate. 有关事件处理程序委托的详细信息,请参阅处理和引发事件For more information about event handler delegates, see Handling and Raising Events.

扩展方法

GetMethodInfo(Delegate) GetMethodInfo(Delegate) GetMethodInfo(Delegate) GetMethodInfo(Delegate)

获取指示指定委托表示的方法的对象。Gets an object that represents the method represented by the specified delegate.

适用于