Asp.net-Mvc

如何在不使用太多 RAM 的情況下正確地從 MVC3 流式傳輸大數據?

  • October 15, 2012

我想HttpResponse.OutputStream一起使用,ContentResult這樣我就可以Flush不時避免.Net使用過多的RAM。

但是所有使用 MVC 的範例都FileStreamResult, EmptyResult, FileResult, ActionResult, ContentResult顯示了將所有數據放入記憶體並傳遞給其中之一的程式碼。還有一篇文章建議EmptyResult與使用一起返回HttpResponse.OutputStream是個壞主意。我還能如何在 MVC 中做到這一點?

從 MVC 伺服器組織大數據(html 或二進制)的可刷新輸出的正確方法是什麼?

為什麼返回EmptyResultor ContentResultorFileStreamResult是個壞主意?

如果您已經有一個流可以使用,您會想要使用 FileStreamResult。很多時候,您可能只能訪問該文件,需要建構一個流,然後將其輸出到客戶端。

System.IO.Stream iStream = null;

// Buffer to read 10K bytes in chunk:
byte[] buffer = new Byte[10000];

// Length of the file:
int length;

// Total bytes to read:
long dataToRead;

// Identify the file to download including its path.
string filepath  = "DownloadFileName";

// Identify the file name.
string  filename  = System.IO.Path.GetFileName(filepath);

try
{
   // Open the file.
   iStream = new System.IO.FileStream(filepath, System.IO.FileMode.Open, 
               System.IO.FileAccess.Read,System.IO.FileShare.Read);


   // Total bytes to read:
   dataToRead = iStream.Length;

   Response.ContentType = "application/octet-stream";
   Response.AddHeader("Content-Disposition", "attachment; filename=" + filename);

   // Read the bytes.
   while (dataToRead > 0)
   {
       // Verify that the client is connected.
       if (Response.IsClientConnected) 
       {
           // Read the data in buffer.
           length = iStream.Read(buffer, 0, 10000);

           // Write the data to the current output stream.
           Response.OutputStream.Write(buffer, 0, length);

           // Flush the data to the HTML output.
           Response.Flush();

           buffer= new Byte[10000];
           dataToRead = dataToRead - length;
       }
       else
       {
           //prevent infinite loop if user disconnects
           dataToRead = -1;
       }
   }
}
catch (Exception ex) 
{
   // Trap the error, if any.
   Response.Write("Error : " + ex.Message);
}
finally
{
   if (iStream != null) 
   {
       //Close the file.
       iStream.Close();
   }
   Response.Close();
}

是解釋上述程式碼的微軟文章。

引用自:https://stackoverflow.com/questions/12433132