datagrid itemrender instance in flex

I have a itemrenderer in datagrid and I am trying to get the instance of itemrender in datagrid keyp开发者_如何学JAVAressevent as follows

var col:DataGridColumn = _datagrid.columns[_datagrid.selectedCells[0].columnIndex];
var myItemrend:MyItemrender = col.itemRenderer as MyItemrender;

But the above myItemrend instance is null. How can I get the itemrenderer instance.

Please help.

Thanks, Rejeev.

I have an itemrenderer in Datagrid and it is used as itemeditor also by rendererIsEditor=true. My itemrenderer has a textinput and a list, where I open the list, for editing, when a focusin event is occurred in textinput, this happens while clicking the cell.

I need the same editing to happen while I enter using the keyboard(Enter), so I am trying to get the instance of the itemrender in Keyboard.ENTER and using this I can dispatch the textinput focusin event.

Thanks, Rejeev.