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 = )]

            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) == ;

            }

        }