Gridview Combobox database value not displaying

Sir,

 

I am  in a windows mini project.

 

My work is to fetch data into gridview comboBox from database.

 

I have did the whole work for this, but data is coming to comboBox cell but not shows in the comboBox. Data showing only shows during Gridview_CellClick event. 

 

I need your help for show the data in GridView CombBoxCell.