在 MouseDown 事件中区分单击和双击

区分鼠标单击和双击事件

处理 MouseDown 事件并确定单击位置和两次单击间的时间间隔，
方法是使用适当的 SystemInformation 属性和 Timer 组件。
根据发生的是单击还是双击，执行适当的操作。下面的代码示例阐释这是如何实现的。

 

  
   

    using
     System;

    using
     System.Drawing;

    using
     System.Windows.Forms;


    namespace
     SingleVersusDoubleClick
{
 
    class
     Form1 : Form
 {
 
    private
     Rectangle hitTestRectangle 
    =
     
    new
     Rectangle();
 
    private
     Rectangle doubleClickRectangle 
    =
     
    new
     Rectangle();
 
    private
     TextBox textBox1 
    =
     
    new
     TextBox();
 
    private
     Timer doubleClickTimer 
    =
     
    new
     Timer();
 
    private
     ProgressBar doubleClickBar 
    =
     
    new
     ProgressBar();
 
    private
     Label label1 
    =
     
    new
     Label();
 
    private
     Label label2 
    =
     
    new
     Label();
 
    private
     
    bool
     isFirstClick 
    =
     
    true
    ;
 
    private
     
    bool
     isDoubleClick 
    =
     
    false
    ;
 
    private
     
    int
     milliseconds 
    =
     
    0
    ;

 [STAThread]
 
    public
     
    static
     
    void
     Main()
 {
 Application.EnableVisualStyles();
 Application.Run(
    new
     Form1());
 }

 
    public
     Form1()
 {
 label1.Location 
    =
     
    new
     Point(
    30
    , 
    5
    );
 label1.Size 
    =
     
    new
     Size(
    100
    , 
    15
    );
 label1.Text 
    =
     
    "
    Hit test rectangle:
    "
    ;

 label2.Location 
    =
     
    new
     Point(
    30
    , 
    70
    );
 label2.Size 
    =
     
    new
     Size(
    100
    , 
    15
    );
 label2.Text 
    =
     
    "
    Double click timer:
    "
    ;

 hitTestRectangle.Location 
    =
     
    new
     Point(
    30
    , 
    20
    );
 hitTestRectangle.Size 
    =
     
    new
     Size(
    100
    , 
    40
    );

 doubleClickTimer.Interval 
    =
     
    100
    ;
 doubleClickTimer.Tick 
    +=
    
 
    new
     EventHandler(doubleClickTimer_Tick);

 doubleClickBar.Location 
    =
     
    new
     Point(
    30
    , 
    85
    );
 doubleClickBar.Minimum 
    =
     
    0
    ;
 doubleClickBar.Maximum 
    =
     SystemInformation.DoubleClickTime;

 textBox1.Location 
    =
     
    new
     Point(
    30
    , 
    120
    );
 textBox1.Size 
    =
     
    new
     Size(
    200
    , 
    100
    );
 textBox1.AutoSize 
    =
     
    false
    ;
 textBox1.Multiline 
    =
     
    true
    ;

 
    this
    .Paint 
    +=
     
    new
     PaintEventHandler(Form1_Paint);
 
    this
    .MouseDown 
    +=
     
    new
     MouseEventHandler(Form1_MouseDown);
 
    this
    .Controls.AddRange(
    new
     Control[] { doubleClickBar, textBox1, 
 label1, label2 });
 }

 
    //
     Detect a valid single click or double click.
    

     
    void
     Form1_MouseDown(
    object
     sender, MouseEventArgs e)
 {
 
    //
     Verify that the mouse click is in the main hit
 
    //
     test rectangle.
    

     
    if
     (
    !
    hitTestRectangle.Contains(e.Location))
 {
 
    return
    ;
 }

 
    //
     This is the first mouse click.
    

     
    if
     (isFirstClick)
 {
 isFirstClick 
    =
     
    false
    ;

 
    //
     Determine the location and size of the double click 
 
    //
     rectangle area to draw around the cursor point.
    

     doubleClickRectangle 
    =
     
    new
     Rectangle(
 e.X 
    -
     (SystemInformation.DoubleClickSize.Width 
    /
     
    2
    ),
 e.Y 
    -
     (SystemInformation.DoubleClickSize.Height 
    /
     
    2
    ),
 SystemInformation.DoubleClickSize.Width,
 SystemInformation.DoubleClickSize.Height);
 Invalidate();

 
    //
     Start the double click timer.
    

     doubleClickTimer.Start();
 }

 
    //
     This is the second mouse click.
    

     
    else
    
 {
 
    //
     Verify that the mouse click is within the double click
 
    //
     rectangle and is within the system-defined double 
 
    //
     click period.
    

     
    if
     (doubleClickRectangle.Contains(e.Location) 
    &&
    
 milliseconds 
    <
     SystemInformation.DoubleClickTime)
 {
 isDoubleClick 
    =
     
    true
    ;
 }
 }
 }

 
    void
     doubleClickTimer_Tick(
    object
     sender, EventArgs e)
 {
 milliseconds 
    +=
     
    100
    ;
 doubleClickBar.Increment(
    100
    );

 
    //
     The timer has reached the double click time limit.
    

     
    if
     (milliseconds 
    >=
     SystemInformation.DoubleClickTime)
 {
 doubleClickTimer.Stop();

 
    if
     (isDoubleClick)
 {
 textBox1.AppendText(
    "
    Perform double click action
    "
    );
 textBox1.AppendText(Environment.NewLine);
 }
 
    else
    
 {
 textBox1.AppendText(
    "
    Perform single click action
    "
    );
 textBox1.AppendText(Environment.NewLine);
 }

 
    //
     Allow the MouseDown event handler to process clicks again.
    

     isFirstClick 
    =
     
    true
    ;
 isDoubleClick 
    =
     
    false
    ;
 milliseconds 
    =
     
    0
    ;
 doubleClickBar.Value 
    =
     
    0
    ;
 }
 }

 
    //
     Paint the hit test and double click rectangles.
    

     
    void
     Form1_Paint(
    object
     sender, PaintEventArgs e)
 {
 
    //
     Draw the border of the main hit test rectangle.
    

     e.Graphics.DrawRectangle(Pens.Black, hitTestRectangle);

 
    //
     Fill in the double click rectangle.
    

     e.Graphics.FillRectangle(Brushes.Blue, doubleClickRectangle);
 }
 }
}
   

 
 

代码源于MSDN