//窗体移动API[DllImport("user32.dll")]public static extern bool ReleaseCapture();[DllImport("user32.dll")]public static extern bool SendMessage(IntPtr hwnd, int wMsg, int wParam, int IParam);public const int WM_SYSCOMMAND = 0x0112;public const int SC_MOVE = 0xF010;public const int HTCAPTION = 0x0002;[DllImport("user32")]private static extern int SendMessage(IntPtr hwnd, int wMsg, int wParam, IntPtr lParam);private const int WM_SETREDRAW = 0xB;private void Form1_MouseDown(object sender, MouseEventArgs e){ if (this.WindowState == FormWindowState.Normal) { ReleaseCapture(); SendMessage(this.Handle, WM_SYSCOMMAND, SC_MOVE + HTCAPTION, 0); }}

1、添加命名空间：using System.Runtime.InteropServices; 2、定义常量值及函数：private const int CS_DropSHADOW = 0x20000; private const int GCL_STYLE = (-26); [DllImport("user32.dll", CharSet = CharSet.Auto)] public static extern int SetClassLong(IntPtr hwnd, int nIndex, int dwNewLong); [DllImport("user32.dll", CharSet = CharSet.Auto)] public static extern int GetClassLong(IntPtr hwnd, int nIndex);3、构造方法下引用：SetClassLong(this.Handle, GCL_STYLE, GetClassLong(this.Handle, GCL_STYLE) | CS_DropSHADOW);