You may receive the error "Cannot have multiple items selected in a DropDownList." when trying to set a value selected in an ASP.NET Dropdownlist.
This error specifically occurs if you are trying to execute a similar code as follows:-
DropDownList1.Items.FindByValue("3").Selected = true;
(or)
DropDownList1.Items.FindByText("Sports").Selected = true;
This error doesnt occur if you try to use
DropDownList1.SelectedIndex = 3;
or
DropDownList1.SelectedItem.Value = "3"; (Wrong way of implementation. But people use this)
The resolution is that, you just have to mention DropDownList1.ClearSelection(); before using DropDownList1.Items.FindByValue("3").Selected = true;
The correct step is as below:-
DropDownList1.ClearSelection();
DropDownList1.Items.FindByValue("3").Selected = true;
or
DropDownList1.ClearSelection();
DropDownList1.Items.FindByText("Sports").Selected = true;
In my next article I will discuss on the common misconception in making a particular Dropdownlist value selected.
Cheers and Happy Programming !!!