public class ApiCopyFile        {            private const int FO_COPY = 0x0002;            private const int FOF_ALLOWUNDO = 0x00044;            //显示进度条  0x00044 // 不显示一个进度对话框 0x0100 显示进度对话框单不显示进度条  0x0002显示进度条和对话框              private const int FOF_SILENT = 0x0002;//0x0100;              //              [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto, Pack = 0)]            public struct SHFILEOPSTRUCT            {                public IntPtr hwnd;                [MarshalAs(UnmanagedType.U4)]                public int wFunc;                public string pFrom;                public string pTo;                public short fFlags;                [MarshalAs(UnmanagedType.Bool)]                public bool fAnyOperationsAborted;                public IntPtr hNameMappings;                public string lpszProgressTitle;            }            [DllImport("shell32.dll", CharSet = CharSet.Auto)]            static extern int SHFileOperation(ref SHFILEOPSTRUCT FileOp);            public static bool DoCopy(string strSource, string strTarget)            {                SHFILEOPSTRUCT fileop = new SHFILEOPSTRUCT();                fileop.wFunc = FO_COPY;                fileop.pFrom = strSource;                fileop.lpszProgressTitle = "复制大文件";                fileop.pTo = strTarget;                //fileop.fFlags = FOF_ALLOWUNDO;                  fileop.fFlags = FOF_SILENT;                return SHFileOperation(ref  fileop) == 0;            }        }