c# - Casting error in my form -

i have combobox in datagridview. error when run it:

unable cast object of type 'system.windows.forms.datagridview' type 'system.windows.forms.combobox'.

what can resolve error?

 combobox combobox;     private void datagridview1_editingcontrolshowing(object sender, datagridvieweditingcontrolshowingeventargs e)     {         if (e.control combobox)         {             combobox = e.control combobox;              if (datagridview1.currentcell.columnindex >= 0)             {                 system.diagnostics.debug.writeline("edit control showing");                 combobox.selectedindexchanged -= new eventhandler(comboboxitems_selectedindexchanged);                 combobox.selectedindexchanged += new eventhandler(comboboxitems_selectedindexchanged);              }         }     }      void comboboxitems_selectedindexchanged(object sender, eventargs e)     {         try         {              int comboboxselectedindex = ((combobox)sender).selectedindex;             string comboboxselectedvalue = ((combobox)sender).selectedtext;             int gridviewselectedrow = datagridview1.currentrow.index;             if (comboboxselectedindex >= 0 && gridviewselectedrow >= 0)             {                 system.diagnostics.debug.writeline("combobox index - " + comboboxselectedindex);                 system.diagnostics.debug.writeline("gridview index - " + gridviewselectedrow);                 if (combobox != null)                 {                     combobox.selectedindexchanged -= new eventhandler(comboboxitems_selectedindexchanged);                    }             }         }         catch(exception e)         {          }     } 

i recommend checking sender object before attempting cast (would confirm decyclone mentioned in answer in addition preventing casting errors):

if(sender comboxbox) {       //cast }