WinForm 重载窗体移动功能

代码均是写在partial class Form1 : Form{}代码块之间

[DllImport("user32.dll ")]
public static extern bool ReleaseCapture();
[DllImport("user32.dll ")]
public static extern bool SendMessage(IntPtr hwnd, int wMsg, int wParam, int lParam);
public const int WM_SYSCOMMAND = 0x0112;
public const int SC_MOVE = 0xF010;
public const int HTCAPTION = 0x0002;

private void Form1_MouseDown(object sender, MouseEventArgs e)
{
    ReleaseCapture();
    SendMessage(this.Handle, WM_SYSCOMMAND, SC_MOVE + HTCAPTION, 0);
}