c# - Why doesn't row command properly work? -

i have download function getting called in rowcommand of gridview. works when click stops working if click(call) function in rowcommand. doesn't throw exception. tried debugging every step no luck.

why ?

download function:

public void downloadfile(string filename) {     try     {         string filepath = filename;         string fullfilepath = server.mappath("../../siteimages/bpa/" + filepath);         response.clear();         response.clearheaders();         response.clearcontent();         response.addheader("content-disposition", "attachment; filename=\"" + path.getfilename(fullfilepath) + "\"");         response.contenttype = contenttype;         response.transmitfile(fullfilepath);     } 

rowcommand:

protected void grdviewuploadedmaterialother_rowcommand(object sender, gridviewcommandeventargs e) {     try     {          if (e.commandname == "download")         {             mdlimgpreview.hide();              string filename = convert.tostring(e.commandargument);              downloadfile(filename);              return;         }          if (e.commandname == "view")         {             imgpreviewed.imageurl = "../../siteimages/bpa/" + e.commandargument.tostring();             mdlimgpreview.show();         }      }     catch (exception ex)     {         resultlabel.resultlabelattributes(ex.message, projectusercontrols.enums.resultlabel_color.red);     }         {         resultpanel.controls.add(resultlabel);     } 

rowdatabound: register button

protected void grdviewuploadedmaterialother_rowdatabound(object sender, gridviewroweventargs e)     {         try         {             linkbutton lb = e.row.findcontrol("btnlinkdownload") linkbutton;             registerdownloadbutton(lb);         }         catch (exception ex)         {             resultlabel.resultlabelattributes(ex.message, projectusercontrols.enums.resultlabel_color.red);         }                 {             resultpanel.controls.add(resultlabel);         }     } 

registration function:

public void registerdownloadbutton(linkbutton lb)     {         try         {              if (lb != null)                 scriptmanager.getcurrent(this).registerpostbackcontrol(lb);           }         catch (exception ex)         {             resultlabel.resultlabelattributes(ex.message, projectusercontrols.enums.resultlabel_color.red);         }                 {             resultpanel.controls.add(resultlabel);         }     } 

gridview:

<asp:gridview runat="server" id="grdviewuploadedmaterialother" width="100%" onrowdatabound="grdviewuploadedmaterialother_rowdatabound"     onrowcommand="grdviewuploadedmaterialother_rowcommand" headerstyle-backcolor="#99cc99"     datakeynames="pk_uploadedmaterialother_id"     autogeneratecolumns="false"     cssclass="table table-condensed table-bordered table-striped table-responsive">     <pagersettings mode="numeric" />     <pagerstyle horizontalalign="center" cssclass="gvwcasespager" />     <columns>          <asp:templatefield headertext="view attachment">             <itemtemplate>                 <asp:linkbutton id="btnlnkviewattachment" runat="server" text="view" commandargument='<%# eval("materialpath") %>' commandname="view"></asp:linkbutton>             </itemtemplate>         </asp:templatefield>         <asp:templatefield headertext="download">             <itemtemplate>                 <asp:linkbutton id="btnlinkdownload" runat="server" text='<%# eval("materialpath") %>'                     commandargument='<%# eval("materialpath") %>' commandname="download"></asp:linkbutton>             </itemtemplate>         </asp:templatefield>         <asp:templatefield headertext="delete">             <itemtemplate>                 <asp:imagebutton id="btndelete" runat="server" imageurl="~/assets/global/images/delete.png"                     commandname="cmddelete" commandargument='<%# container.dataitemindex %>'                     controlstyle-width="20px"                     controlstyle-height="20px" />             </itemtemplate>         </asp:templatefield>     </columns> </asp:gridview> 

try add updatepanel control gridview solve problem.

refere following code, may you.

<asp:templatefield headertext="download">         <itemtemplate>           <asp:updatepanel runat="server" updatemode="conditional" id="fileuploadpanel">         <contenttemplate>                     <asp:linkbutton id="btnlinkdownload" runat="server" text='<%# eval("materialpath") %>'                             commandargument='<%# eval("materialpath") %>' commandname="download"></asp:linkbutton>         </contenttemplate>                       <triggers>                         <asp:postbacktrigger controlid="btnlinkdownload" />                      </triggers>     </asp:updatepanel>          </itemtemplate>     </asp:templatefield>