Bewerken

Delen via


DrawToolTipEventArgs.AssociatedControl Property

Definition

Gets the control for which the ToolTip is being drawn.

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

Property Value

The Control that is associated with the ToolTip when the Draw event occurs. The return value will be null if the ToolTip is not associated with a control.

Examples

The following code example demonstrates how to custom draw the ToolTip. The example creates a ToolTip and associates it to three Button controls located on the Form. The example sets the OwnerDraw property to true and handles the Draw event. In the Draw event handler, the ToolTip is custom drawn differently depending on what button the ToolTip is being displayed for as indicated by the DrawToolTipEventArgs.AssociatedControl property.

The following code example excerpt demonstrates how to use the AssociatedControl property. See the DrawToolTipEventArgs class overview for the complete code example.

   // 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

Remarks

Because the ToolTip can be associated with multiple controls through the ToolTip.SetToolTip method, the AssociatedControl property can be used to determine which control the Draw event is associated with. This is helpful if you want to perform different ToolTip customization based on the associated control.

Applies to

See also