C#-創建自定義雙擊事件

.NET Compact Framework 不支持按鈕的 Windows 窗體 DoubleClick 事件。但是您可以創建一個從 Button 類派生的控件來實現該事件。

創建自定義雙擊事件

1. 創建一個從 System.Windows.Forms.Button 類派生的類。

2. 聲明一個 DoubleClick 事件。

3. 使用代碼重寫 OnClick 方法，以在指定時間內單擊按鈕時引發 DoubleClick 事件。

示例：

此示例創建一個 DoubleClickButton 自定義控件並在一個窗體上實現該控件。

using System;
using System.Windows.Forms;
using System.Drawing;

namespace ButtonDClick
{
    public class Form1 : System.Windows.Forms.Form
    {
        // Track the number of 
        // double-clicks with the count variable.
        int count = 0;

        public Form1()
        {
            InitializeComponent();

            // Display OK button for closing.
            this.MinimizeBox = false;

            // Create an instance of the DoubleClickButton class.
            DoubleClickButton dClickB = new DoubleClickButton();

            dClickB.Bounds = new Rectangle(10,10,200,30);
            dClickB.Text = "Double-click me!";
            Controls.Add(dClickB);

            // Add the DClick event hander to the DoubleClick event.
            dClickB.DoubleClick += new EventHandler(DClick);
        }

        protected override void Dispose( bool disposing )
        {
            base.Dispose( disposing );
        }

        private void InitializeComponent()
        {
            this.Text = "Form1";
        }

        private void DClick(object o, EventArgs e)
        {
            // Display the number of double-clicks.
            MessageBox.Show("Double-click count = " + ++count);
        }

        static void Main() 
        {
            Application.Run(new Form1());
        }

        // Derive a button with extended funtionality
        // from the Button class.
        public class DoubleClickButton : System.Windows.Forms.Button 
        { 
            // Note that the DoubleClickTime property gets 
            // the maximum number of milliseconds allowed between 
            // mouse clicks for a double-click to be valid.
            int previousClick = SystemInformation.DoubleClickTime;

            public new event EventHandler DoubleClick;

            protected override void OnClick(EventArgs e)
            {
                int now = System.Environment.TickCount;

                // A double-click is detected if the the time elapsed
                // since the last click is within DoubleClickTime.
                if ( now - previousClick <= SystemInformation.DoubleClickTime)
                {
                    // Raise the DoubleClick event.
                    if (DoubleClick != null)
                        DoubleClick(this,EventArgs.Empty);
                }

                // Set previousClick to now so that 
                // subsequent double-clicks can be detected.
                previousClick = now;

                // Allow the base class to raise the regular Click event.
                base.OnClick(e);
            }

            // Event handling code for the DoubleClick event.
            protected new virtual void OnDoubleClick(EventArgs e)
            {
                if (this.DoubleClick != null)
                    this.DoubleClick(this, e);
            }
        }
    }
}