c# - 如何将内存流下载到文件？

Question

我正在使用下面的示例代码在 C# 中写入内存流并将其下载到文件中。

MemoryStream memoryStream = new MemoryStream();
TextWriter textWriter = new StreamWriter(memoryStream);
textWriter.WriteLine("Something");           
byte[] bytesInStream = new byte[memoryStream.Length];
memoryStream.Write(bytesInStream, 0, bytesInStream.Length);
memoryStream.Close();          
Response.Clear();
Response.ContentType = "application/force-download";
Response.AddHeader("content-disposition",
                   "attachment; filename=name_you_file.xls");
Response.BinaryWrite(bytesInStream);
Response.End();

我收到以下错误:

Specified argument was out of the range of valid values.
Parameter name: offset

可能是什么原因？

Answer 1

在您将数据复制到数组的代码中，TextWriter 可能尚未刷新数据。这将在您 Flush() 或 Close() 时发生。

看看这是否有效:

MemoryStream memoryStream = new MemoryStream();
TextWriter textWriter = new StreamWriter(memoryStream);
textWriter.WriteLine("Something");   
textWriter.Flush(); // added this line
byte[] bytesInStream = memoryStream.ToArray(); // simpler way of converting to array
memoryStream.Close(); 

Response.Clear();
Response.ContentType = "application/force-download";
Response.AddHeader("content-disposition", "attachment;    filename=name_you_file.xls");
Response.BinaryWrite(bytesInStream);
Response.End();