DrawToolTipEventArgs.AssociatedControl 属性

public:
 property System::Windows::Forms::Control ^ AssociatedControl { System::Windows::Forms::Control ^ get(); };

public System.Windows.Forms.Control AssociatedControl { get; }

public System.Windows.Forms.Control? AssociatedControl { get; }

member this.AssociatedControl : System.Windows.Forms.Control

Public ReadOnly Property AssociatedControl As Control

属性值

发生 Control 事件时与 ToolTip 关联的 Draw。 如果工具提示未与控件关联，则返回值为 null。

示例

下面的代码示例演示如何自定义绘制 ToolTip。 该示例创建 ，并将其关联到 位于 上的Form三Button个ToolTip控件。 该示例将 OwnerDraw 属性设置为 true 并处理 Draw 事件。 在事件处理程序中 Draw ， ToolTip 根据 显示的按钮 ToolTip ，以不同的方式自定义绘制，如 属性所示 DrawToolTipEventArgs.AssociatedControl 。

下面的代码示例摘录演示了如何使用 AssociatedControl 属性。 有关完整的代码示例， DrawToolTipEventArgs 请参阅类概述。

   // 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();
      }
   }

// 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();
    }
}

' 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

注解

ToolTip由于 可以通过 方法与多个控件ToolTip.SetToolTip相关联，AssociatedControl因此 可以使用 属性来确定与事件关联的控件Draw。 如果要根据关联的控件执行不同的工具提示自定义，这非常有用。

另请参阅

• SetToolTip(Control, String)
• AssociatedWindow
• Draw