DrawToolTipEventHandler Делегат

Определение

Пространство имен:

System.Windows.Forms

Сборка:

System.Windows.Forms.dll

Представляет метод, обрабатывающий событие Draw объекта 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)

Параметры

sender

Object

Источник события.

e

DrawToolTipEventArgs

Объект DrawToolTipEventArgs, содержащий данные события.

Примеры

В следующем примере кода показано, как настроить рисование ToolTip. В этом примере создается ToolTip и связывается с тремя Button элементами управления, расположенными в Form. В примере свойству OwnerDraw присваивается значение true и обрабатывается Draw событие . В обработчике Draw событий настраиваемый ToolTip объект рисуется по-разному в зависимости от того, для какой кнопки ToolTip отображается , как указано в свойстве DrawToolTipEventArgs.AssociatedControl .

#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.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

Комментарии

Событие ToolTip.Draw вызывается классом , ToolTip когда ToolTip рисуется , а ToolTip.OwnerDraw значение свойства равно true. Класс DrawToolTipEventArgs содержит все сведения, необходимые для рисования ToolTip, включая текст всплывающей подсказки Rectangle, и объект, Graphics на котором должен быть выполнен рисунок. Чтобы настроить внешний вид всплывающей подсказки, используйте Rectangle , чтобы определить границы подсказки, и Graphics объект для выполнения настраиваемого документа. Вы можете увеличить границы ToolTip , прежде чем он будет отображен, обрабатывая Popup событие .

При создании делегата DrawToolTipEventHandler необходимо указать метод, обрабатывающий событие. Чтобы связать событие с обработчиком событий, нужно добавить в событие экземпляр делегата. Обработчик событий вызывается всякий раз, когда происходит событие, если делегат не удален. Дополнительные сведения о делегатах обработчиков событий см. в разделе Обработка и вызов событий.

Методы расширения