C# winform 无边框 窗体的拖动

当船体设置为FormborderStyle='none'

[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;

  this.MouseDown += new System.Windows.Forms.MouseEventHandler(this.Form1_MouseDown);

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