net读取文件字节流要注意的小细节

            var bytes = new byte[fileLenght+];
            var numBytesToRead = (int)fileLenght;
            var numBytesRead = ;
            using (fs)
            {
                do
                {
                    int n = fs.Read(bytes, numBytesRead, );
                    numBytesRead += n;
                    numBytesToRead -= n;

                } while (numBytesToRead > );

                fs.Close();
            }

https://docs.microsoft.com/zh-cn/dotnet/api/system.io.stream.read?redirectedfrom=MSDN&view=netframework-4.7.2#System_IO_Stream_Read_System_Byte___System_Int32_System_Int32_

http://www.cnblogs.com/JimmyZheng/archive/2012/03/17/2402814.html