c# 检测鼠标在任何地方的点击（表单内部和外部）

Question

这是否可以在 if 语句中的任何位置（表单内部和外部）检测鼠标单击（左/右）？如果可能，怎么做？

if(MouseButtons.LeftButton == MouseButtonState.Pressed){

...

}

Answer 1

当用户在表单控件外单击时，它会失去焦点，您可以使用它。这意味着您必须使用_Deactivate(object sender, EventArgs e)表单控件的事件来完成这项工作。因为 which 将在表单失去焦点并且不再是活动表单时触发。让Form1是形式，那么事件将如下所示：

private void Form1_Deactivate(object sender, EventArgs e)
{
    // Your code here to handle this event
}

Answer 2

这是一个初学者，如果我理解您对“从窗口外点击”的需求，而 Hans Passant 的建议不符合您的需求。您可能需要为Form1_Click.

注意：提供此代码是为了说明该概念。此示例中的线程同步不是 100% 正确的。检查此答案的历史，以尝试更“线程正确”的答案，该答案有时会引发异常。作为替代方案，要摆脱所有线程问题，您可以让 StartWaitingForClickFromOutside 中的任务始终运行（也就是始终处于“侦听”模式），而不是尝试检测“表单内”或“表单外” " 状态并相应地开始/停止循环。

using System;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApp1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();

            this.MouseLeave += Form1_MouseLeave;
            this.Leave += Form1_Leave;
            this.Deactivate += Form1_Deactivate;
            this.MouseEnter += Form1_MouseEnter;
            this.Activated += Form1_Activated;
            this.Enter += Form1_Enter;
            this.VisibleChanged += Form1_VisibleChanged;
        }

        private AutoResetEvent are = new AutoResetEvent(false);

        // You could create just one handler, but this is to show what you need to link to
        private void Form1_MouseLeave(object sender, EventArgs e) => StartWaitingForClickFromOutside();
        private void Form1_Leave(object sender, EventArgs e) => StartWaitingForClickFromOutside();
        private void Form1_Deactivate(object sender, EventArgs e) => StartWaitingForClickFromOutside();
        private void StartWaitingForClickFromOutside()
        {
            are.Reset();
            var ctx = new SynchronizationContext();

            var task = Task.Run(() =>
            {
                while (true)
                {
                    if (are.WaitOne(1)) break;
                    if (MouseButtons == MouseButtons.Left)
                    {
                        ctx.Send(CLickFromOutside, null);
                        // You might need to put in a delay here and not break depending on what you want to accomplish
                        break;
                    }
                }
            });
        }

        private void CLickFromOutside(object state) => MessageBox.Show("Clicked from outside of the window");
        private void Form1_MouseEnter(object sender, EventArgs e) => are.Set();
        private void Form1_Activated(object sender, EventArgs e) => are.Set();
        private void Form1_Enter(object sender, EventArgs e) => are.Set();
        private void Form1_VisibleChanged(object sender, EventArgs e)
        {
            if (Visible) are.Set();
            else StartWaitingForClickFromOutside();
        }
    }
}

如果我对您的理解有误，您可能会发现这很有用：将子控件的点击事件传递给父控件