C#-创建自定义双击事件

.NET Compact Framework 不支持按钮的 Windows 窗体 DoubleClick 事件。但是您可以创建一个从 Button 类派生的控件来实现该事件。

创建自定义双击事件

1. 创建一个从 System.Windows.Forms.Button 类派生的类。

2. 声明一个 DoubleClick 事件。

3. 使用代码重写 OnClick 方法，以在指定时间内单击按钮时引发 DoubleClick 事件。

示例：

此示例创建一个 DoubleClickButton 自定义控件并在一个窗体上实现该控件。

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);
            }
        }
    }
}