c# - Download with chunks. Need to stop page loading in order to start download with Internet Download Manager -

i using following code download huge (around 2 gb) files.

view code

<a href="/checkdownload/index">download</a> 

controller-action method code

code download file in chunks.

public actionresult index()     {         system.io.stream istream = null;         // buffer read 10k bytes in chunk:         byte[] buffer = new byte[10000];         int length;         long datatoread;              //creates whole path clicked file resides.             string finalpath = @"e:\builds\sharepoint\fileabc.csv";             string filename = system.io.path.getfilename(finalpath);             try             {             istream = new system.io.filestream(finalpath, system.io.filemode.open,                         system.io.fileaccess.read, system.io.fileshare.read);             // total bytes read:             datatoread = istream.length;             response.contenttype = "application/octet-stream";             response.addheader("content-disposition", "attachment; filename=" + filename);             //response.addheader("connection", "keep-alive");             // read bytes.             while (datatoread > 0)             {                 // verify client connected.                 if (response.isclientconnected)                 {                     // read data in buffer.                     length = istream.read(buffer, 0, 10000);                      // write data current output stream.                     response.outputstream.write(buffer, 0, length);                      // flush data html output.                     response.flush();                     buffer = new byte[10000];                     datatoread = datatoread - length;                 }                 else                 {                     //prevent infinite loop if user disconnects                     datatoread = -1;                 }             }         }         catch (exception e)         {             //return view();         }                 {             if (istream != null)             {                 //close file.                 istream.close();             }             response.close();         }         return view();      } 

when try use internet download manager(idm) in order download, opens new tab , until stop loading page, download not start , idm shows connecting. when stop page load, download starts idm.

while in normal download via browser, starts download.

what reason it? new framework, appreciated.

update

i noticed happening in chrome , not internet explorer.