使用C#将点击发送到面板中的背景窗口相对位置

Question

我使用 C#，我有一个带有 button1、button2 和 panel1 的应用程序，如果我点击 button1，它会打开一个到 panel1 的外部程序，然后如果我点击 button2，它会向窗口发送背景点击，工作正常. 但问题是这个点击位置不是相对于面板，也不是去正确的地方。它发送点击实际光标在哪里。

我使用的代码片段：

PerformRightClick(proc.MainWindowHandle, new Point(54, 42));

void PerformRightClick(IntPtr hwnd, Point point)
{
     var pointPtr = MakeLParam(point.X, point.Y);
     SendMessage(hwnd, WM_MOUSEMOVE, IntPtr.Zero, pointPtr);
     SendMessage(hwnd, WM_RBUTTONDOWN, IntPtr.Zero, pointPtr);
     SendMessage(hwnd, WM_RBUTTONUP, IntPtr.Zero, pointPtr);
}

[System.Runtime.InteropServices.DllImport("user32.dll")]
static extern int SendMessage(IntPtr hWnd, int Msg, IntPtr wParam, IntPtr lParam);
IntPtr MakeLParam(int x, int y) => (IntPtr)((y << 16) | (x & 0xFFFF));

Answer 1

根据我的测试，当我们想要发送点击到面板时，我们需要使用panel.Handle。

这是一个代码示例，您可以参考。

private const Int32 WM_MOUSEMOVE = 0x0200;

        private const Int32 WM_RBUTTONDOWN = 0x0204;
        private const Int32 WM_RBUTTONUP = 0x0205;
        [System.Runtime.InteropServices.DllImport("user32.dll")]
        static extern int SendMessage(IntPtr hWnd, int Msg, IntPtr wParam, IntPtr lParam);
        IntPtr MakeLParam(int x, int y) => (IntPtr)((y << 16) | (x & 0xFFFF));

        private void button1_Click(object sender, EventArgs e)
        {
            PerformRightClick(panel1.Handle, new Point(20, 30));
        }

        void PerformRightClick(IntPtr hwnd, Point point)
        {
            var pointPtr = MakeLParam(point.X, point.Y);
            SendMessage(hwnd, WM_MOUSEMOVE, IntPtr.Zero, pointPtr);
            SendMessage(hwnd, WM_RBUTTONDOWN, IntPtr.Zero, pointPtr);
            SendMessage(hwnd, WM_RBUTTONUP, IntPtr.Zero, pointPtr);
        }

        private void panel1_Click(object sender, EventArgs e)
        {
            MessageBox.Show("Panel is clicked");
        }

        private void button2_Click(object sender, EventArgs e)
        {
            PerformRightClick(this.Handle, new Point(20, 30));
        }

        private void Form1_Click(object sender, EventArgs e)
        {
            MessageBox.Show("Form is clicked");
        }

图片：

如上图，当我们点击button1时，点击panel，点击button2时点击Form。