C# Winform - 保持 MouseDown 并加入其他对象，对象 MouseMove 不起作用

Question

当对象A上的MouseDown然后mousemove到objectB时，objectB(mousemove handle)无法调用。

如何让其他对象检测到mousemovehandle，当mousedown进入对象区域之前。

    public Test()
    {
        InitializeComponent();
        this.Size = new Size(500, 500);
        Panel pl = new Panel();
        pl.Size = new Size(200, 200);
        pl.Location = new Point(0, 0);
        pl.BackColor = Color.Pink;

        Label lb = new Label();
        lb.Text = "Keep MouseDown and move to Panel2 , Panel2 MouseMoveHandler not work";
        lb.Dock = DockStyle.Fill;
        pl.Controls.Add(lb);

        TextBox tb = new TextBox();
        tb.Multiline = true;
        tb.Size = new Size(400, 100);
        tb.Location = new Point(0,300);

        Panel pl2 = new Panel();
        pl2.Size = new Size(100, 100);
        pl2.Location = new Point(0, 0);
        pl2.BackColor = Color.Red;
        pl2.Location = new Point(300, 0);
        pl2.MouseMove += new MouseEventHandler(delegate (object o, MouseEventArgs a)
        {
            tb.AppendText(a.X + "," + a.Y);
        });

        this.Controls.Add(pl);
        this.Controls.Add(pl2);
        this.Controls.Add(tb);
    }

Answer 1

您看到的是标准行为。如果您将鼠标移到该对象之外，这是在按住鼠标的同时获取该对象的 MouseMove 事件的唯一方法。

如果您想在任何时间点找出光标下的控件（如果需要，您可以在 MouseMove 事件中进行），您可以使用此代码：

[System.Runtime.InteropServices.DllImport("user32.dll")]
private static extern IntPtr WindowFromPoint(Point pnt);

public static Control GetControlUnderCursor() {
  var handle = WindowFromPoint(Control.MousePosition);
  if (handle != IntPtr.Zero)
    return Control.FromHandle(handle);
  return null;
}

如果您将表单的 Capture property to true (that's what is happening on your control when you hold the mouse button down) also and you can check Control.MouseButtons 设置为在需要时找出按下了哪些鼠标按钮，则可以在表单的 MouseMove 事件中使用此代码..

C# Winform - 保持 MouseDown 并加入其他对象，对象 MouseMove 不起作用

C# Winform - Keep MouseDown and join to other object the object MouseMove not work

c#

mousemove

winforms

mousedown