c# - Server Error in '/WebSite8' Application. Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index -

description:

an exception occurred during execution of current web request. please review stack trace more information error , originated in code.

exception details:

system.argument out of range exception: index out of range. must non-negative , less size of collection. parameter name: index 

code:

  protected void imagebutton1_click (object sender, eventargs e)      {         imagebutton lnkbtn = sender imagebutton;         gridviewrow gvrow = lnkbtn.namingcontainer gridviewrow;              string filepath = gridview2.datakeys[gvrow.rowindex].value.tostring();              response.contenttype = "image/jpg";             response.addheader("content-disposition", "attachment;filename=\"" + filepath + "\"");             response.transmitfile(server.mappath(filepath));             response.end();      } 

it looks me facing issue @ point

string filepath = gridview2.datakeys[gvrow.rowindex].value.tostring(); 

when trying pull out value of datakey gvrow.rowindex having value greater element count.

try debug , see count of element , gvrow.rowindex setting up.