MouseEventHandler 委托

定义

表示将处理窗体、控件或其他组件的 MouseDownMouseUpMouseMove 事件的方法。

public delegate void MouseEventHandler(System::Object ^ sender, MouseEventArgs ^ e);
public delegate void MouseEventHandler(object sender, MouseEventArgs e);
public delegate void MouseEventHandler(object? sender, MouseEventArgs e);
type MouseEventHandler = delegate of obj * MouseEventArgs -> unit
Public Delegate Sub MouseEventHandler(sender As Object, e As MouseEventArgs)

参数

sender
Object

事件源。

e
MouseEventArgs

包含事件数据的 MouseEventArgs

示例

下面的代码示例演示如何使用不同的鼠标事件绘制鼠标在 a Panel上的路径。 将行段添加到 GraphicsPath 每个 MouseMove 行段以及 MouseDown 发生的事件。 若要更新图形,将Invalidate针对每个MouseDownMouseUp事件调用Panel该方法。 此外,事件发生时 MouseWheel ,图形路径将向上或向下滚动。 其他鼠标事件(如 MouseHover)也会在屏幕上标识。 屏幕上还显示有关类中的鼠标 SystemInformation 的其他信息。

#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

注解

创建 MouseEventHandler 委托时,需要标识将处理该事件的方法。 若要将事件与事件处理程序关联,请将该委托的一个实例添加到事件中。 除非移除了该委托,否则每当发生该事件时就会调用事件处理程序。 有关使用委托处理事件的详细信息,请参阅 处理和引发事件

扩展方法

GetMethodInfo(Delegate)

获取指示指定委托表示的方法的对象。

适用于

另请参阅