DrawToolTipEventHandler Delegate
Assembly: System.Windows.Forms (in system.windows.forms.dll)
'Declaration Public Delegate Sub DrawToolTipEventHandler ( _ sender As Object, _ e As DrawToolTipEventArgs _ ) 'Usage Dim instance As New DrawToolTipEventHandler(AddressOf HandlerMethod)
/** @delegate */ public delegate void DrawToolTipEventHandler ( Object sender, DrawToolTipEventArgs e )
JScript supports the use of delegates, but not the declaration of new ones.
Parameters
- sender
The source of the event.
- e
A DrawToolTipEventArgs that contains the event data.
The ToolTip.Draw event is raised by the ToolTip class when the ToolTip is drawn and the ToolTip.OwnerDraw property value is true. 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.
When you create a DrawToolTipEventHandler delegate, you identify the method that will handle the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For more information about event handler delegates, see Events and Delegates.
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 upon what button the ToolTip is being displayed for as indicated by the DrawToolTipEventArgs.AssociatedControl property.
Imports System 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
package ToolTipExample;
import System.*;
import System.Drawing.*;
import System.Drawing.GDI.*;
import System.Windows.Forms.*;
import System.Windows.Forms.VisualStyles.*;
// Form for the ToolTip example.
public class ToolTipExampleForm extends 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.set_AutoPopDelay(5000);
this.toolTip1.set_InitialDelay(500);
this.toolTip1.set_OwnerDraw(true);
this.toolTip1.set_ReshowDelay(10);
this.toolTip1.add_Draw(new DrawToolTipEventHandler(this.toolTip1_Draw));
// Create button1 and set initial values.
this.button1 = new System.Windows.Forms.Button();
this.button1.set_Location(new System.Drawing.Point(8, 8));
this.button1.set_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.set_Location(new System.Drawing.Point(8, 32));
this.button2.set_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.set_Location(new System.Drawing.Point(8, 56));
this.button3.set_Text("Button 3");
this.toolTip1.SetToolTip(this.button3, "Button3 tip text");
// Set up the Form.
this.get_Controls().AddRange(new Control[]
{ this.button1, this.button2, this.button3 });
this.set_Text("owner drawn ToolTip example");
} //ToolTipExampleForm
// Clean up any resources being used.
protected void Dispose(boolean disposing)
{
if (disposing) {
toolTip1.Dispose();
}
super.Dispose(disposing);
} //Dispose
// The main entry point for the application.
/** @attribute STAThread()
*/
public static void main(String[] args)
{
Application.Run(new ToolTipExampleForm());
} //main
// Handles drawing the ToolTip.
private void toolTip1_Draw(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.get_AssociatedControl().Equals(button1)) {
// Draw the standard background.
e.DrawBackground();
// Draw the custom border to appear 3-dimensional.
e.get_Graphics().DrawLines(SystemPens.get_ControlLightLight(),
new Point[] { new Point(0, e.get_Bounds().get_Height() - 1),
new Point(0, 0), new Point(e.get_Bounds().get_Width() - 1, 0)});
e.get_Graphics().DrawLines(SystemPens.get_ControlDarkDark(),
new Point[] { new Point(0, e.get_Bounds().get_Height() - 1),
new Point(e.get_Bounds().get_Width() - 1,
e.get_Bounds().get_Height() - 1),
new Point(e.get_Bounds().get_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.get_AssociatedControl().Equals(button2)) {
// Draw the custom background.
e.get_Graphics().FillRectangle(SystemBrushes.get_ActiveCaption(),
e.get_Bounds());
// Draw the standard border.
e.DrawBorder();
// Draw the custom text.
// The using block will dispose the StringFormat automatically.
StringFormat sf = new StringFormat();
try {
sf.set_Alignment(StringAlignment.Center);
sf.set_LineAlignment(StringAlignment.Center);
sf.set_HotkeyPrefix(System.Drawing.Text.HotkeyPrefix.None);
sf.set_FormatFlags(StringFormatFlags.NoWrap);
Font f = new Font("Tahoma", 9);
try {
e.get_Graphics().DrawString(e.get_ToolTipText(), f,
SystemBrushes.get_ActiveCaptionText(),
RectangleF.op_Implicit(e.get_Bounds()), sf);
}
finally {
f.Dispose();
}
}
finally {
sf.Dispose();
}
}
// Draw the ToolTip using default values if the ToolTip is
// for button3.
else {
if (e.get_AssociatedControl().Equals(button3)) {
e.DrawBackground();
e.DrawBorder();
e.DrawText();
}
}
}
} //toolTip1_Draw
} //ToolTipExampleForm
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.