I've tried several times to create a dropdown list inside a grid by following this
link. But I still cannot create a dropdown list inside a grid. It always shows error when I run the program. It says ""An exception of type 'System.ArgumentException' occurred in mscorlib.dll but was not handled in user code. Additional information: Object of type 'POSF.Models.ProductViewModel' cannot be converted to type 'System.String'." I don't know how to do, I have done all like the link said.
Please help me
Here I attach my grid, controller, model, and error message