DrawToolTipEventArgs.AssociatedControl Proprietà

Definizione

Ottiene il controllo per cui viene disegnato l'oggetto ToolTip.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; }
member this.AssociatedControl : System.Windows.Forms.Control
Public ReadOnly Property AssociatedControl As Control

Valore della proprietà

Control

Oggetto Control associato all'oggetto ToolTip quando si verifica l'evento Draw.The Control that is associated with the ToolTip when the Draw event occurs. Il valore restituito è null se la descrizione comandi non è associata a un controllo.The return value will be null if the ToolTip is not associated with a control.

Esempio

Nell'esempio di codice riportato di seguito viene illustrato come creare un oggetto personalizzato ToolTip .The following code example demonstrates how to custom draw the ToolTip. Nell'esempio viene creato un oggetto ToolTip e lo si associa a tre Button controlli che si trovano in Form .The example creates a ToolTip and associates it to three Button controls located on the Form. Nell'esempio la proprietà viene impostata OwnerDraw su true e viene gestito l' Draw evento.The example sets the OwnerDraw property to true and handles the Draw event. Nel Draw gestore eventi, ToolTip è personalizzato disegnata in modo diverso a seconda del pulsante ToolTip visualizzato per come indicato dalla DrawToolTipEventArgs.AssociatedControl Proprietà.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.

Nell'esempio di codice seguente viene illustrato come utilizzare la AssociatedControl Proprietà.The following code example excerpt demonstrates how to use the AssociatedControl property. DrawToolTipEventArgsPer l'esempio di codice completo, vedere Cenni preliminari sulla classe.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

Commenti

Poiché ToolTip può essere associato a più controlli tramite il ToolTip.SetToolTip metodo, la AssociatedControl proprietà può essere utilizzata per determinare a quale controllo Draw è associato l'evento.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. Questa operazione è utile se si desidera eseguire una personalizzazione diversa della descrizione comando basata sul controllo associato.This is helpful if you want to perform different ToolTip customization based on the associated control.

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