ToolTip.Draw Event
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
public:
event System::Windows::Forms::DrawToolTipEventHandler ^ Draw;public event System.Windows.Forms.DrawToolTipEventHandler Draw;public event System.Windows.Forms.DrawToolTipEventHandler? Draw;member this.Draw : System.Windows.Forms.DrawToolTipEventHandler Public Custom Event Draw As DrawToolTipEventHandler Event Type
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.
#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
Remarks
With the Draw event, you can customize the appearance of the ToolTip.
The Draw event is raised by the ToolTip class when the ToolTip is drawn and the ToolTip.OwnerDraw property value is true and the IsBalloon property is false. 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. 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. You can increase the bounds of the ToolTip before it is shown by handling the Popup event.
For more information about handling events, see Handling and Raising Events.
Applies to
See also
Werk met ons samen op GitHub
De bron voor deze inhoud vindt u op GitHub, waar u ook problemen en pull-aanvragen kunt maken en bekijken. Raadpleeg onze gids voor inzenders voor meer informatie.
