控件阴影

 #region 窗体边框阴影效果变量申明 const int CS_DropSHADOW = 0x20000; const int GCL_STYLE = (-26); //声明Win32 API 
[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); 
#endregion 
public Form1() {
 InitializeComponent(); 
SetClassLong(this.Handle, GCL_STYLE, GetClassLong(this.Handle, GCL_STYLE) | CS_DropSHADOW); //API函数加载，实现窗体边框阴影效果 
}