My combo Box column in Grid control doesn''t show any items

i filled my combo Box column with a collection object.Indeed my datasource is a colection .the object is full but it does't show any items in my grid column when I drop down the combo.
Why:
Form_Load()
{
\\collectionObj had been filled before
Mygrid[1,3].datasource = collectionObj;
Mygrid[1,3].DisplayMember = "Name";
Mygrid[1,3].ValueMember = "Id";
}

Hi Shayesteh,

Thanks for your interest in Syncfusion products.

Please try the following sample for this issue.

http://websamples.syncfusion.com//samples/Grid.Windows/F77191/main.htm

Please let me know if this helps.

Regards,
Rajadurai