Control.MouseWheel 事件
定義
重要
部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。
當滑鼠滾輪移動時，控制器仍保持對焦。
public:
event System::Windows::Forms::MouseEventHandler ^ MouseWheel;[System.ComponentModel.Browsable(false)]
public event System.Windows.Forms.MouseEventHandler MouseWheel;[System.ComponentModel.Browsable(false)]
public event System.Windows.Forms.MouseEventHandler? MouseWheel;[<System.ComponentModel.Browsable(false)>]
member this.MouseWheel : System.Windows.Forms.MouseEventHandler Public Custom Event MouseWheel As MouseEventHandler 事件類型
- 屬性
範例
以下程式碼範例示範使用不同的滑鼠事件來繪製滑鼠在 Panel的路徑。 每個事件及發生的事件都會被加入 GraphicsPathMouseMoveMouseDown 一條線段。 要更新圖形，則 Invalidate 呼叫該方法對 Panel on each MouseDown 和 MouseUp 事件。 此外，當事件發生時 MouseWheel ，圖形路徑會向上或向下捲動。 螢幕上也會標示出其他滑鼠事件，如 MouseHover。 螢幕上還會顯示關於該職業滑鼠 SystemInformation 的額外資訊。
#using <System.dll>
#using <System.Windows.Forms.dll>
#using <System.Drawing.dll>
using namespace System;
using namespace System::Drawing;
using namespace System::Windows::Forms;
namespace MouseEvent
{
public ref class Form1: public System::Windows::Forms::Form
{
private:
System::Windows::Forms::Panel^ panel1;
System::Windows::Forms::Label ^ label1;
System::Windows::Forms::Label ^ label2;
System::Windows::Forms::Label ^ label3;
System::Windows::Forms::Label ^ label4;
System::Windows::Forms::Label ^ label5;
System::Windows::Forms::Label ^ label6;
System::Windows::Forms::Label ^ label7;
System::Windows::Forms::Label ^ label8;
System::Windows::Forms::Label ^ label9;
System::Windows::Forms::Button^ clearButton;
System::Drawing::Drawing2D::GraphicsPath^ mousePath;
System::Windows::Forms::GroupBox^ groupBox1;
int fontSize;
public:
Form1()
{
fontSize = 20;
mousePath = gcnew System::Drawing::Drawing2D::GraphicsPath;
this->panel1 = gcnew System::Windows::Forms::Panel;
this->label1 = gcnew System::Windows::Forms::Label;
this->clearButton = gcnew System::Windows::Forms::Button;
this->label2 = gcnew System::Windows::Forms::Label;
this->label3 = gcnew System::Windows::Forms::Label;
this->label4 = gcnew System::Windows::Forms::Label;
this->label5 = gcnew System::Windows::Forms::Label;
this->label6 = gcnew System::Windows::Forms::Label;
this->label7 = gcnew System::Windows::Forms::Label;
this->label8 = gcnew System::Windows::Forms::Label;
this->label9 = gcnew System::Windows::Forms::Label;
this->groupBox1 = gcnew System::Windows::Forms::GroupBox;
// Mouse Events Label
this->label1->Location = System::Drawing::Point( 24, 504 );
this->label1->Size = System::Drawing::Size( 392, 23 );
// DoubleClickSize Label
this->label2->AutoSize = true;
this->label2->Location = System::Drawing::Point( 24, 48 );
this->label2->Size = System::Drawing::Size( 35, 13 );
// DoubleClickTime Label
this->label3->AutoSize = true;
this->label3->Location = System::Drawing::Point( 24, 72 );
this->label3->Size = System::Drawing::Size( 35, 13 );
// MousePresent Label
this->label4->AutoSize = true;
this->label4->Location = System::Drawing::Point( 24, 96 );
this->label4->Size = System::Drawing::Size( 35, 13 );
// MouseButtons Label
this->label5->AutoSize = true;
this->label5->Location = System::Drawing::Point( 24, 120 );
this->label5->Size = System::Drawing::Size( 35, 13 );
// MouseButtonsSwapped Label
this->label6->AutoSize = true;
this->label6->Location = System::Drawing::Point( 320, 48 );
this->label6->Size = System::Drawing::Size( 35, 13 );
// MouseWheelPresent Label
this->label7->AutoSize = true;
this->label7->Location = System::Drawing::Point( 320, 72 );
this->label7->Size = System::Drawing::Size( 35, 13 );
// MouseWheelScrollLines Label
this->label8->AutoSize = true;
this->label8->Location = System::Drawing::Point( 320, 96 );
this->label8->Size = System::Drawing::Size( 35, 13 );
// NativeMouseWheelSupport Label
this->label9->AutoSize = true;
this->label9->Location = System::Drawing::Point( 320, 120 );
this->label9->Size = System::Drawing::Size( 35, 13 );
// Mouse Panel
this->panel1->Anchor = static_cast<System::Windows::Forms::AnchorStyles>(System::Windows::Forms::AnchorStyles::Top | System::Windows::Forms::AnchorStyles::Left | System::Windows::Forms::AnchorStyles::Right);
this->panel1->BackColor = System::Drawing::SystemColors::ControlDark;
this->panel1->Location = System::Drawing::Point( 16, 160 );
this->panel1->Size = System::Drawing::Size( 664, 320 );
this->panel1->MouseUp += gcnew System::Windows::Forms::MouseEventHandler( this, &Form1::panel1_MouseUp );
this->panel1->Paint += gcnew System::Windows::Forms::PaintEventHandler( this, &Form1::panel1_Paint );
this->panel1->MouseEnter += gcnew System::EventHandler( this, &Form1::panel1_MouseEnter );
this->panel1->MouseHover += gcnew System::EventHandler( this, &Form1::panel1_MouseHover );
this->panel1->MouseMove += gcnew System::Windows::Forms::MouseEventHandler( this, &Form1::panel1_MouseMove );
this->panel1->MouseLeave += gcnew System::EventHandler( this, &Form1::panel1_MouseLeave );
this->panel1->MouseDown += gcnew System::Windows::Forms::MouseEventHandler( this, &Form1::panel1_MouseDown );
this->panel1->MouseWheel += gcnew System::Windows::Forms::MouseEventHandler( this, &Form1::panel1_MouseWheel );
// Clear Button
this->clearButton->Anchor = static_cast<System::Windows::Forms::AnchorStyles>(System::Windows::Forms::AnchorStyles::Top | System::Windows::Forms::AnchorStyles::Right);
this->clearButton->Location = System::Drawing::Point( 592, 504 );
this->clearButton->TabIndex = 1;
this->clearButton->Text = "Clear";
this->clearButton->Click += gcnew System::EventHandler( this, &Form1::clearButton_Click );
// GroupBox
this->groupBox1->Anchor = static_cast<System::Windows::Forms::AnchorStyles>(System::Windows::Forms::AnchorStyles::Top | System::Windows::Forms::AnchorStyles::Left | System::Windows::Forms::AnchorStyles::Right);
this->groupBox1->Location = System::Drawing::Point( 16, 24 );
this->groupBox1->Size = System::Drawing::Size( 664, 128 );
this->groupBox1->Text = "System::Windows::Forms::SystemInformation";
// Set up how the form should be displayed and add the controls to the form.
this->ClientSize = System::Drawing::Size( 696, 534 );
array<System::Windows::Forms::Control^>^temp0 = {this->label9,this->label8,this->label7,this->label6,this->label5,this->label4,this->label3,this->label2,this->clearButton,this->panel1,this->label1,this->groupBox1};
this->Controls->AddRange( temp0 );
this->Text = "Mouse Event Example";
// Displays information about the system mouse.
label2->Text = "SystemInformation::DoubleClickSize: {0}",SystemInformation::DoubleClickSize;
label3->Text = "SystemInformation::DoubleClickTime: {0}",SystemInformation::DoubleClickTime;
label4->Text = "SystemInformation::MousePresent: {0}",SystemInformation::MousePresent;
label5->Text = "SystemInformation::MouseButtons: {0}",SystemInformation::MouseButtons;
label6->Text = "SystemInformation::MouseButtonsSwapped: {0}",SystemInformation::MouseButtonsSwapped;
label7->Text = "SystemInformation::MouseWheelPresent: {0}",SystemInformation::MouseWheelPresent;
label8->Text = "SystemInformation::MouseWheelScrollLines: {0}",SystemInformation::MouseWheelScrollLines;
label9->Text = "SystemInformation::NativeMouseWheelSupport: {0}",SystemInformation::NativeMouseWheelSupport;
}
private:
void panel1_MouseDown( Object^ /*sender*/, System::Windows::Forms::MouseEventArgs^ e )
{
// Update the mouse path with the mouse information
Point mouseDownLocation = Point(e->X,e->Y);
String^ eventString = nullptr;
switch ( e->Button )
{
case ::MouseButtons::Left:
eventString = "L";
break;
case ::MouseButtons::Right:
eventString = "R";
break;
case ::MouseButtons::Middle:
eventString = "M";
break;
case ::MouseButtons::XButton1:
eventString = "X1";
break;
case ::MouseButtons::XButton2:
eventString = "X2";
break;
case ::MouseButtons::None:
default:
break;
}
if ( eventString != nullptr )
{
mousePath->AddString( eventString, FontFamily::GenericSerif, (int)FontStyle::Bold, (float)fontSize, mouseDownLocation, StringFormat::GenericDefault );
}
else
{
mousePath->AddLine( mouseDownLocation, mouseDownLocation );
}
panel1->Focus();
panel1->Invalidate();
}
void panel1_MouseEnter( Object^ sender, System::EventArgs^ /*e*/ )
{
// Update the mouse event label to indicate the MouseEnter event occurred.
label1->Text = String::Concat( sender->GetType(), ": MouseEnter" );
}
void panel1_MouseHover( Object^ sender, System::EventArgs^ /*e*/ )
{
// Update the mouse event label to indicate the MouseHover event occurred.
label1->Text = String::Concat( sender->GetType(), ": MouseHover" );
}
void panel1_MouseLeave( Object^ sender, System::EventArgs^ /*e*/ )
{
// Update the mouse event label to indicate the MouseLeave event occurred.
label1->Text = String::Concat( sender->GetType(), ": MouseLeave" );
}
void panel1_MouseMove( Object^ /*sender*/, System::Windows::Forms::MouseEventArgs^ e )
{
// Update the mouse path that is drawn onto the Panel.
int mouseX = e->X;
int mouseY = e->Y;
mousePath->AddLine( mouseX, mouseY, mouseX, mouseY );
}
void panel1_MouseWheel( Object^ /*sender*/, System::Windows::Forms::MouseEventArgs^ e )
{
// Update the drawing based upon the mouse wheel scrolling.
int numberOfTextLinesToMove = e->Delta * SystemInformation::MouseWheelScrollLines / 120;
int numberOfPixelsToMove = numberOfTextLinesToMove * fontSize;
if ( numberOfPixelsToMove != 0 )
{
System::Drawing::Drawing2D::Matrix^ translateMatrix = gcnew System::Drawing::Drawing2D::Matrix;
translateMatrix->Translate( 0, (float)numberOfPixelsToMove );
mousePath->Transform(translateMatrix);
}
panel1->Invalidate();
}
void panel1_MouseUp( Object^ /*sender*/, System::Windows::Forms::MouseEventArgs^ e )
{
Point mouseUpLocation = System::Drawing::Point( e->X, e->Y );
// Show the number of clicks in the path graphic.
int numberOfClicks = e->Clicks;
mousePath->AddString( String::Format( " {0}", numberOfClicks ), FontFamily::GenericSerif, (int)FontStyle::Bold, (float)fontSize, mouseUpLocation, StringFormat::GenericDefault );
panel1->Invalidate();
}
void panel1_Paint( Object^ /*sender*/, System::Windows::Forms::PaintEventArgs^ e )
{
// Perform the painting of the Panel.
e->Graphics->DrawPath( System::Drawing::Pens::DarkRed, mousePath );
}
void clearButton_Click( Object^ /*sender*/, System::EventArgs^ /*e*/ )
{
// Clear the Panel display.
delete mousePath;
mousePath = gcnew System::Drawing::Drawing2D::GraphicsPath;
panel1->Invalidate();
}
};
}
[STAThread]
int main()
{
Application::Run( gcnew MouseEvent::Form1 );
}
using System;
using System.Drawing;
using System.Windows.Forms;
namespace MouseEvent
{
public class Form1 : System.Windows.Forms.Form
{
private System.Windows.Forms.Panel panel1;
private System.Windows.Forms.Label label1;
private System.Windows.Forms.Label label2;
private System.Windows.Forms.Label label3;
private System.Windows.Forms.Label label4;
private System.Windows.Forms.Label label5;
private System.Windows.Forms.Label label6;
private System.Windows.Forms.Label label7;
private System.Windows.Forms.Label label8;
private System.Windows.Forms.Label label9;
private System.Windows.Forms.Button clearButton;
private System.Drawing.Drawing2D.GraphicsPath mousePath;
private System.Windows.Forms.GroupBox groupBox1;
private int fontSize = 20;
[STAThread]
static void Main()
{
Application.Run(new Form1());
}
public Form1()
{
mousePath = new System.Drawing.Drawing2D.GraphicsPath();
this.panel1 = new System.Windows.Forms.Panel();
this.label1 = new System.Windows.Forms.Label();
this.clearButton = new System.Windows.Forms.Button();
this.label2 = new System.Windows.Forms.Label();
this.label3 = new System.Windows.Forms.Label();
this.label4 = new System.Windows.Forms.Label();
this.label5 = new System.Windows.Forms.Label();
this.label6 = new System.Windows.Forms.Label();
this.label7 = new System.Windows.Forms.Label();
this.label8 = new System.Windows.Forms.Label();
this.label9 = new System.Windows.Forms.Label();
this.groupBox1 = new System.Windows.Forms.GroupBox();
// Mouse Events Label
this.label1.Location = new System.Drawing.Point(24, 504);
this.label1.Size = new System.Drawing.Size(392, 23);
// DoubleClickSize Label
this.label2.AutoSize = true;
this.label2.Location = new System.Drawing.Point(24, 48);
this.label2.Size = new System.Drawing.Size(35, 13);
// DoubleClickTime Label
this.label3.AutoSize = true;
this.label3.Location = new System.Drawing.Point(24, 72);
this.label3.Size = new System.Drawing.Size(35, 13);
// MousePresent Label
this.label4.AutoSize = true;
this.label4.Location = new System.Drawing.Point(24, 96);
this.label4.Size = new System.Drawing.Size(35, 13);
// MouseButtons Label
this.label5.AutoSize = true;
this.label5.Location = new System.Drawing.Point(24, 120);
this.label5.Size = new System.Drawing.Size(35, 13);
// MouseButtonsSwapped Label
this.label6.AutoSize = true;
this.label6.Location = new System.Drawing.Point(320, 48);
this.label6.Size = new System.Drawing.Size(35, 13);
// MouseWheelPresent Label
this.label7.AutoSize = true;
this.label7.Location = new System.Drawing.Point(320, 72);
this.label7.Size = new System.Drawing.Size(35, 13);
// MouseWheelScrollLines Label
this.label8.AutoSize = true;
this.label8.Location = new System.Drawing.Point(320, 96);
this.label8.Size = new System.Drawing.Size(35, 13);
// NativeMouseWheelSupport Label
this.label9.AutoSize = true;
this.label9.Location = new System.Drawing.Point(320, 120);
this.label9.Size = new System.Drawing.Size(35, 13);
// Mouse Panel
this.panel1.Anchor = ((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left)
| System.Windows.Forms.AnchorStyles.Right);
this.panel1.BackColor = System.Drawing.SystemColors.ControlDark;
this.panel1.Location = new System.Drawing.Point(16, 160);
this.panel1.Size = new System.Drawing.Size(664, 320);
this.panel1.MouseUp += new System.Windows.Forms.MouseEventHandler(this.panel1_MouseUp);
this.panel1.Paint += new System.Windows.Forms.PaintEventHandler(this.panel1_Paint);
this.panel1.MouseEnter += new System.EventHandler(this.panel1_MouseEnter);
this.panel1.MouseHover += new System.EventHandler(this.panel1_MouseHover);
this.panel1.MouseMove += new System.Windows.Forms.MouseEventHandler(this.panel1_MouseMove);
this.panel1.MouseLeave += new System.EventHandler(this.panel1_MouseLeave);
this.panel1.MouseDown += new System.Windows.Forms.MouseEventHandler(this.panel1_MouseDown);
this.panel1.MouseWheel += new System.Windows.Forms.MouseEventHandler(this.panel1_MouseWheel);
// Clear Button
this.clearButton.Anchor = (System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Right);
this.clearButton.Location = new System.Drawing.Point(592, 504);
this.clearButton.TabIndex = 1;
this.clearButton.Text = "Clear";
this.clearButton.Click += new System.EventHandler(this.clearButton_Click);
// GroupBox
this.groupBox1.Anchor = ((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left)
| System.Windows.Forms.AnchorStyles.Right);
this.groupBox1.Location = new System.Drawing.Point(16, 24);
this.groupBox1.Size = new System.Drawing.Size(664, 128);
this.groupBox1.Text = "System.Windows.Forms.SystemInformation";
// Set up how the form should be displayed and add the controls to the form.
this.ClientSize = new System.Drawing.Size(696, 534);
this.Controls.AddRange(new System.Windows.Forms.Control[] {
this.label9,this.label8,this.label7,this.label6,
this.label5,this.label4,this.label3,this.label2,
this.clearButton,this.panel1,this.label1,this.groupBox1});
this.Text = "Mouse Event Example";
// Displays information about the system mouse.
label2.Text = "SystemInformation.DoubleClickSize: " + SystemInformation.DoubleClickSize.ToString();
label3.Text = "SystemInformation.DoubleClickTime: " + SystemInformation.DoubleClickTime.ToString();
label4.Text = "SystemInformation.MousePresent: " + SystemInformation.MousePresent.ToString();
label5.Text = "SystemInformation.MouseButtons: " + SystemInformation.MouseButtons.ToString();
label6.Text = "SystemInformation.MouseButtonsSwapped: " + SystemInformation.MouseButtonsSwapped.ToString();
label7.Text = "SystemInformation.MouseWheelPresent: " + SystemInformation.MouseWheelPresent.ToString();
label8.Text = "SystemInformation.MouseWheelScrollLines: " + SystemInformation.MouseWheelScrollLines.ToString();
label9.Text = "SystemInformation.NativeMouseWheelSupport: " + SystemInformation.NativeMouseWheelSupport.ToString();
}
private void panel1_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
{
// Update the mouse path with the mouse information
Point mouseDownLocation = new Point(e.X, e.Y);
string eventString = null;
switch (e.Button) {
case MouseButtons.Left:
eventString = "L";
break;
case MouseButtons.Right:
eventString = "R";
break;
case MouseButtons.Middle:
eventString = "M";
break;
case MouseButtons.XButton1:
eventString = "X1";
break;
case MouseButtons.XButton2:
eventString = "X2";
break;
case MouseButtons.None:
default:
break;
}
if (eventString != null)
{
mousePath.AddString(eventString, FontFamily.GenericSerif, (int)FontStyle.Bold, fontSize, mouseDownLocation, StringFormat.GenericDefault);
}
else
{
mousePath.AddLine(mouseDownLocation,mouseDownLocation);
}
panel1.Focus();
panel1.Invalidate();
}
private void panel1_MouseEnter(object sender, System.EventArgs e)
{
// Update the mouse event label to indicate the MouseEnter event occurred.
label1.Text = sender.GetType().ToString() + ": MouseEnter";
}
private void panel1_MouseHover(object sender, System.EventArgs e)
{
// Update the mouse event label to indicate the MouseHover event occurred.
label1.Text = sender.GetType().ToString() + ": MouseHover";
}
private void panel1_MouseLeave(object sender, System.EventArgs e)
{
// Update the mouse event label to indicate the MouseLeave event occurred.
label1.Text = sender.GetType().ToString() + ": MouseLeave";
}
private void panel1_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
{
// Update the mouse path that is drawn onto the Panel.
int mouseX = e.X;
int mouseY = e.Y;
mousePath.AddLine(mouseX,mouseY,mouseX,mouseY);
}
private void panel1_MouseWheel(object sender, System.Windows.Forms.MouseEventArgs e)
{
// Update the drawing based upon the mouse wheel scrolling.
int numberOfTextLinesToMove = e.Delta * SystemInformation.MouseWheelScrollLines / 120;
int numberOfPixelsToMove = numberOfTextLinesToMove * fontSize;
if (numberOfPixelsToMove != 0) {
System.Drawing.Drawing2D.Matrix translateMatrix = new System.Drawing.Drawing2D.Matrix();
translateMatrix.Translate(0, numberOfPixelsToMove);
mousePath.Transform(translateMatrix);
}
panel1.Invalidate();
}
private void panel1_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e)
{
Point mouseUpLocation = new System.Drawing.Point(e.X, e.Y);
// Show the number of clicks in the path graphic.
int numberOfClicks = e.Clicks;
mousePath.AddString(" " + numberOfClicks.ToString(),
FontFamily.GenericSerif, (int)FontStyle.Bold,
fontSize, mouseUpLocation, StringFormat.GenericDefault);
panel1.Invalidate();
}
private void panel1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{
// Perform the painting of the Panel.
e.Graphics.DrawPath(System.Drawing.Pens.DarkRed, mousePath);
}
private void clearButton_Click(object sender, System.EventArgs e)
{
// Clear the Panel display.
mousePath.Dispose();
mousePath = new System.Drawing.Drawing2D.GraphicsPath();
panel1.Invalidate();
}
}
}
Imports System.Drawing
Imports System.Windows.Forms
Namespace MouseEvent
' Summary description for Form1.
Public NotInheritable Class Form1
Inherits System.Windows.Forms.Form
Friend WithEvents panel1 As System.Windows.Forms.Panel
Private label1 As System.Windows.Forms.Label
Private label2 As System.Windows.Forms.Label
Private label3 As System.Windows.Forms.Label
Private label4 As System.Windows.Forms.Label
Private label5 As System.Windows.Forms.Label
Private label6 As System.Windows.Forms.Label
Private label7 As System.Windows.Forms.Label
Private label8 As System.Windows.Forms.Label
Private label9 As System.Windows.Forms.Label
Friend WithEvents clearButton As System.Windows.Forms.Button
Private mousePath As System.Drawing.Drawing2D.GraphicsPath
Private groupBox1 As System.Windows.Forms.GroupBox
Private fontSize As Integer = 20
<System.STAThread()> _
Public Shared Sub Main()
System.Windows.Forms.Application.Run(New Form1())
End Sub
Public Sub New()
mousePath = New System.Drawing.Drawing2D.GraphicsPath()
Me.panel1 = New System.Windows.Forms.Panel()
Me.label1 = New System.Windows.Forms.Label()
Me.clearButton = New System.Windows.Forms.Button()
Me.label2 = New System.Windows.Forms.Label()
Me.label3 = New System.Windows.Forms.Label()
Me.label4 = New System.Windows.Forms.Label()
Me.label5 = New System.Windows.Forms.Label()
Me.label6 = New System.Windows.Forms.Label()
Me.label7 = New System.Windows.Forms.Label()
Me.label8 = New System.Windows.Forms.Label()
Me.label9 = New System.Windows.Forms.Label()
Me.groupBox1 = New System.Windows.Forms.GroupBox()
' Mouse Events Label
Me.label1.Location = New System.Drawing.Point(24, 504)
Me.label1.Size = New System.Drawing.Size(392, 23)
' DoubleClickSize Label
Me.label2.AutoSize = True
Me.label2.Location = New System.Drawing.Point(24, 48)
Me.label2.Size = New System.Drawing.Size(35, 13)
' DoubleClickTime Label
Me.label3.AutoSize = True
Me.label3.Location = New System.Drawing.Point(24, 72)
Me.label3.Size = New System.Drawing.Size(35, 13)
' MousePresent Label
Me.label4.AutoSize = True
Me.label4.Location = New System.Drawing.Point(24, 96)
Me.label4.Size = New System.Drawing.Size(35, 13)
' MouseButtons Label
Me.label5.AutoSize = True
Me.label5.Location = New System.Drawing.Point(24, 120)
Me.label5.Size = New System.Drawing.Size(35, 13)
' MouseButtonsSwapped Label
Me.label6.AutoSize = True
Me.label6.Location = New System.Drawing.Point(320, 48)
Me.label6.Size = New System.Drawing.Size(35, 13)
' MouseWheelPresent Label
Me.label7.AutoSize = True
Me.label7.Location = New System.Drawing.Point(320, 72)
Me.label7.Size = New System.Drawing.Size(35, 13)
' MouseWheelScrollLines Label
Me.label8.AutoSize = True
Me.label8.Location = New System.Drawing.Point(320, 96)
Me.label8.Size = New System.Drawing.Size(35, 13)
' NativeMouseWheelSupport Label
Me.label9.AutoSize = True
Me.label9.Location = New System.Drawing.Point(320, 120)
Me.label9.Size = New System.Drawing.Size(35, 13)
' Mouse Panel
Me.panel1.Anchor = System.Windows.Forms.AnchorStyles.Top Or _
System.Windows.Forms.AnchorStyles.Left Or _
System.Windows.Forms.AnchorStyles.Right
Me.panel1.BackColor = System.Drawing.SystemColors.ControlDark
Me.panel1.Location = New System.Drawing.Point(16, 160)
Me.panel1.Size = New System.Drawing.Size(664, 320)
' Clear Button
Me.clearButton.Anchor = System.Windows.Forms.AnchorStyles.Top Or _
System.Windows.Forms.AnchorStyles.Right
Me.clearButton.Location = New System.Drawing.Point(592, 504)
Me.clearButton.TabIndex = 1
Me.clearButton.Text = "Clear"
' GroupBox
Me.groupBox1.Anchor = System.Windows.Forms.AnchorStyles.Top Or _
System.Windows.Forms.AnchorStyles.Left Or _
System.Windows.Forms.AnchorStyles.Right
Me.groupBox1.Location = New System.Drawing.Point(16, 24)
Me.groupBox1.Size = New System.Drawing.Size(664, 128)
Me.groupBox1.Text = "System.Windows.Forms.SystemInformation"
' Set up how the form should be displayed and add the controls to the form.
Me.ClientSize = New System.Drawing.Size(696, 534)
Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.label9, _
Me.label8, Me.label7, Me.label6, Me.label5, Me.label4, _
Me.label3, Me.label2, Me.clearButton, Me.panel1, Me.label1, Me.groupBox1})
Me.Text = "Mouse Event Example"
' Display information about the system mouse.
label2.Text = "SystemInformation.DoubleClickSize: " + SystemInformation.DoubleClickSize.ToString()
label3.Text = "SystemInformation.DoubleClickTime: " + SystemInformation.DoubleClickTime.ToString()
label4.Text = "SystemInformation.MousePresent: " + SystemInformation.MousePresent.ToString()
label5.Text = "SystemInformation.MouseButtons: " + SystemInformation.MouseButtons.ToString()
label6.Text = "SystemInformation.MouseButtonsSwapped: " + SystemInformation.MouseButtonsSwapped.ToString()
label7.Text = "SystemInformation.MouseWheelPresent: " + SystemInformation.MouseWheelPresent.ToString()
label8.Text = "SystemInformation.MouseWheelScrollLines: " + SystemInformation.MouseWheelScrollLines.ToString()
label9.Text = "SystemInformation.NativeMouseWheelSupport: " + SystemInformation.NativeMouseWheelSupport.ToString()
End Sub
Private Sub panel1_MouseDown(sender As Object, e As System.Windows.Forms.MouseEventArgs) Handles panel1.MouseDown
' Update the mouse path with the mouse information
Dim mouseDownLocation As New Point(e.X, e.Y)
Dim eventString As String = Nothing
Select Case e.Button
Case MouseButtons.Left
eventString = "L"
Case MouseButtons.Right
eventString = "R"
Case MouseButtons.Middle
eventString = "M"
Case MouseButtons.XButton1
eventString = "X1"
Case MouseButtons.XButton2
eventString = "X2"
Case MouseButtons.None:
eventString = Nothing
End Select
If (eventString IsNot Nothing) Then
mousePath.AddString(eventString, FontFamily.GenericSerif, CInt(FontStyle.Bold), fontSize, mouseDownLocation, StringFormat.GenericDefault)
Else
mousePath.AddLine(mouseDownLocation, mouseDownLocation)
End If
panel1.Focus()
panel1.Invalidate()
End Sub
Private Sub panel1_MouseEnter(sender As Object, e As System.EventArgs) Handles panel1.MouseEnter
' Update the mouse event label to indicate the MouseEnter event occurred.
label1.Text = sender.GetType().ToString() + ": MouseEnter"
End Sub
Private Sub panel1_MouseHover(sender As Object, e As System.EventArgs) Handles panel1.MouseHover
' Update the mouse event label to indicate the MouseHover event occurred.
label1.Text = sender.GetType().ToString() + ": MouseHover"
End Sub
Private Sub panel1_MouseLeave(sender As Object, e As System.EventArgs) Handles panel1.MouseLeave
' Update the mouse event label to indicate the MouseLeave event occurred.
label1.Text = sender.GetType().ToString() + ": MouseLeave"
End Sub
Private Sub panel1_MouseMove(sender As Object, e As System.Windows.Forms.MouseEventArgs) Handles panel1.MouseMove
' Update the mouse path that is drawn onto the Panel.
Dim mouseX As Integer = e.X
Dim mouseY As Integer = e.Y
mousePath.AddLine(mouseX, mouseY, mouseX, mouseY)
End Sub
Private Sub panel1_MouseWheel(sender As Object, e As System.Windows.Forms.MouseEventArgs) Handles panel1.MouseWheel
' Update the drawing based upon the mouse wheel scrolling.
Dim numberOfTextLinesToMove As Integer = CInt(e.Delta * SystemInformation.MouseWheelScrollLines / 120)
Dim numberOfPixelsToMove As Integer = numberOfTextLinesToMove * fontSize
If numberOfPixelsToMove <> 0 Then
Dim translateMatrix As New System.Drawing.Drawing2D.Matrix()
translateMatrix.Translate(0, numberOfPixelsToMove)
mousePath.Transform(translateMatrix)
End If
panel1.Invalidate()
End Sub
Private Sub panel1_MouseUp(sender As Object, e As System.Windows.Forms.MouseEventArgs) Handles panel1.MouseUp
Dim mouseUpLocation As New System.Drawing.Point(e.X, e.Y)
' Show the number of clicks in the path graphic.
Dim numberOfClicks As Integer = e.Clicks
mousePath.AddString(" " + numberOfClicks.ToString(), _
FontFamily.GenericSerif, CInt(FontStyle.Bold), _
fontSize, mouseUpLocation, StringFormat.GenericDefault)
panel1.Invalidate()
End Sub
Private Sub panel1_Paint(sender As Object, e As System.Windows.Forms.PaintEventArgs) Handles panel1.Paint
' Perform the painting of the Panel.
e.Graphics.DrawPath(System.Drawing.Pens.DarkRed, mousePath)
End Sub
Private Sub clearButton_Click(sender As Object, e As System.EventArgs) Handles clearButton.Click
' Clear the Panel display.
mousePath.Dispose()
mousePath = New System.Drawing.Drawing2D.GraphicsPath()
panel1.Invalidate()
End Sub
End Class
End Namespace
備註
處理 MouseWheel 事件時，遵循與滑鼠滾輪相關的使用者介面（UI）標準非常重要。 MouseEventArgs.Delta屬性值表示滑鼠滾輪被移動了多少。 當累積的 delta 正負 120 時，UI 應該會捲動。 UI 應該會捲動每個 delta 值時， SystemInformation.MouseWheelScrollLines 屬性回傳的邏輯行數。 你也可以在 120 單位以內的小幅度捲動更平滑，但比例應該保持不變，也就是 SystemInformation.MouseWheelScrollLines 每 120 個 delta 單位的輪子移動，捲動的線數就要保持不變。
如需更多關於處理滑鼠滾輪訊息的資訊，請參閱 WM_MOUSEWHEEL 主題。
老鼠事件發生順序如下：
如需處理事件的詳細資訊，請參閱 處理和引發事件。
