TextBoxButton点击事件

Question

我使用流代码来创建TextBoxButton控件。当我在主类的“TextBoxButton_Click”void中编写代码时，它工作得很好。但是，当我在窗体上拖动此自定义控件时，如何管理双击此控件时的单击事件？如何确定用户点击了文本框内的文本框或按钮？

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace CustomControl
{
    public class TextBoxButton : TextBox
    {
        [System.Runtime.InteropServices.DllImport("user32.dll")]
        private static extern IntPtr SendMessage(IntPtr hWnd, int msg, IntPtr wp, IntPtr lp);

        public Button mbutton;
        public Button button
        {
            get { return mbutton; }
            set { this.mbutton = value; }
        }
        protected override void OnCreateControl()
        {
            this.Controls.Add(this.mbutton);
            SetRightToLeft();
            base.OnCreateControl();
        }
        private void SetRightToLeft()
        {
            if (RightToLeft == RightToLeft.Yes)
            {
                mbutton.Dock = DockStyle.Left;
            }
            else
            {
                mbutton.Dock = DockStyle.Right;
            }
        }
        protected override void OnRightToLeftChanged(EventArgs e)
        {
            SetRightToLeft();
            base.OnRightToLeftChanged(e);
        }
        public TextBoxButton()
        {
            mbutton = new Button();
            mbutton.Width = 20;
            mbutton.Cursor = Cursors.Hand;
            mbutton.Click += TextBoxButton_Click;
            // Send EM_SETMARGINS to prevent text from disappearing underneath the button
            SendMessage(Handle, 0xd3, (IntPtr)2, (IntPtr)(mbutton.Width << 16));

        }

        private void TextBoxButton_Click(object sender, EventArgs e)
        {
                      }
    }
}

Answer 1

您可以在自定义控件中创建新事件，在将控件放到窗体上后可以访问这些事件。

public EventHandler TextBoxClick;
public EventHandler ButtonClick;

// Attach this handler to your TextBox.Click event
private void TextBox_Click(object sender, EventArgs e)
{
    if (TextBoxClick != null)
        TextBoxClick(sender, e);
}

// Attach this handler to your Button.Click event
private void Button_Click(object sender, EventArgs e)
{
    if (ButtonClick != null)
        ButtonClick(sender, e);
}

另一种方法是让你的TextBox和按钮成为public，但这看起来有点花招。

Answer 2

如果希望Windows窗体设计器在程序员双击窗体设计器中的TextBoxButton时默认情况下为控件创建Click事件，请使用DefaultEvent属性。

下面的代码还演示了如何创建您自己的Click事件，该事件在单击按钮时引发。

[DefaultEvent("Click")]
public class TextBoxButton : TextBox
{
    public TextBoxButton()
    {
        mbutton = new Button();
        mbutton.Width = 20;
        mbutton.Cursor = Cursors.Hand;
        mbutton.Click += TextBoxButton_Click;
        // Send EM_SETMARGINS to prevent text from disappearing underneath the button
        SendMessage(Handle, 0xd3, (IntPtr)2, (IntPtr)(mbutton.Width << 16));
    }

    private void TextBoxButton_Click(object sender, EventArgs e)
    {
        //  Raise our own Click event
        OnClick();
    }

    public event EventHandler Click;

    protected void OnClick() {
        var handler = Click;
        if (handler != null)
        {
            handler(this, EventArgs.Empty);
        }
    }

Answer 3

不如在构造函数中添加一个事件处理程序：

public TextBoxButton(){
//...
//...
 mbutton.Click += Mbutton_Click;
}

private void Mbutton_Click(object sender, EventArgs e) {
    MessageBox.Show("StackOverFlow");
}