C#FileStream复制大文件

        /// <summary>

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        /// 复制文件 网管网www_bitscn_com

        /// </summary> 网管联盟bitsCN@com

        /// <param name="fromFile">要复制的文件</param>

        /// <param name="toFile">要保存的位置</param>

        /// <param name="lengthEachTime">每次复制的长度</param>

        private void CopyFile(string fromFile, string toFile, int lengthEachTime) 网管bitscn_com

        {

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            FileStream fileToCopy = new FileStream(fromFile, FileMode.Open, FileAccess.Read);

            FileStream copyToFile = new FileStream(toFile, FileMode.Append, FileAccess.Write); 网管下载dl.bitscn.com

            int lengthToCopy; 网管u家u.bitscn@com

            if (lengthEachTime < fileToCopy.Length)//如果分段拷贝，即每次拷贝内容小于文件总长度

            { 网管网www_bitscn_com

                byte[] buffer = new byte[lengthEachTime];

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                int copied = 0;

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                while (copied <= ((int)fileToCopy.Length - lengthEachTime))//拷贝主体部分

                { 网管论坛bbs_bitsCN_com

                    lengthToCopy = fileToCopy.Read(buffer, 0, lengthEachTime);

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                    fileToCopy.Flush(); 网管网www.bitscn.com

                    copyToFile.Write(buffer, 0, lengthEachTime);

                    copyToFile.Flush(); 网管联盟bitsCN_com

                    copyToFile.Position = fileToCopy.Position; 中国网管论坛bbs.bitsCN.com

                    copied += lengthToCopy;

                }

                int left = (int)fileToCopy.Length - copied;//拷贝剩余部分 网管联盟bitsCN_com

                lengthToCopy = fileToCopy.Read(buffer, 0, left);

                fileToCopy.Flush();

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                copyToFile.Write(buffer, 0, left);

                copyToFile.Flush();

            }

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            else//如果整体拷贝，即每次拷贝内容大于文件总长度 网管u家u.bitscn@com

            { 网管下载dl.bitscn.com

                byte[] buffer = new byte[fileToCopy.Length]; 网管u家u.bitsCN.com

                fileToCopy.Read(buffer,0,(int)fileToCopy.Length);

                fileToCopy.Flush();

                copyToFile.Write(buffer, 0, (int)fileToCopy.Length);

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                copyToFile.Flush(); 网管u家u.bitscn@com

            }

            fileToCopy.Close(); 网管联盟bitsCN_com

            copyToFile.Close();

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        } 网管论坛bbs_bitsCN_com