一个登录窗体，FormBorderStyle属性设置为None,打开后不能挪动位置，有时候会妨碍使用，有点恶心。网上找了段内容，实现拖动效果：

 #region 无边框拖动效果,Form被PictureBox覆盖，Form事件不会被触发 [System.Runtime.InteropServices.DllImport("user32.dll")]//拖动无窗体的控件 public static extern bool ReleaseCapture(); [System.Runtime.InteropServices.DllImport("user32.dll")] public static extern bool SendMessage(IntPtr hwnd, int wMsg, int wParam, int lParam); [System.Runtime.InteropServices.DllImportAttribute("user32.dll")] internal static extern int SendMessage(IntPtr hWnd, int Msg, IntPtr wParam, IntPtr lParam); public const int WM_SYSCOMMAND = 0x0112; public const int SC_MOVE = 0xF010; public const int HTCAPTION = 0x0002; private void pictureBoxBackground_MouseDown(object sender, MouseEventArgs e) { if (e.Button == MouseButtons.Left) { ReleaseCapture(); SendMessage(this.Handle, WM_SYSCOMMAND, SC_MOVE + HTCAPTION, 0); } } public const int WM_NCLBUTTONDOWN = 0xA1; public const int HT_CAPTION = 0x2; public const int MOUSEWHEEL = 0x020A; private void pictureBoxBackground_MouseMove(object sender, MouseEventArgs e) { if (e.Button == MouseButtons.Left) { ReleaseCapture(); SendMessage(Handle, WM_NCLBUTTONDOWN, HT_CAPTION, 0); } } #endregion