ToolTip.Draw 事件
定义
重要
一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。 对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。
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 事件类型
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 以不同的方式自定义绘制，具体取决于 显示的按钮 ToolTip ，如 属性所示 DrawToolTipEventArgs.AssociatedControl 。
#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
注解
当Draw绘制 且属性值true为 且 ToolTip.OwnerDraw 属性为 时ToolTip， IsBalloonfalse类将引发 ToolTip 事件。 类 DrawToolTipEventArgs 包含绘制 ToolTip所需的所有信息，包括工具提示文本、 Rectangle和 Graphics 应对其执行绘图的对象。 若要自定义工具提示的外观，请使用 Rectangle 确定工具提示的边界，并使用 Graphics 对象执行自定义绘图。 通过处理 Popup 事件，ToolTip可以在显示 之前增加 的边界。
有关处理事件的详细信息，请参阅 处理和引发事件。
