Auto ComboBox Index Change on TabControl

[stewarts]

I have a TabControl with 2 TabPages on my form. TabPage1 contains a ComboBox (dropdownstyle = dropdownlist) that is bound to a database table. I want the ComboBox to be blank upon form initialization, so I set the ComboBox.SelectedIndex equal to -1. The ComboBox is blank when the form is initialized, but when I click over to TabPage2 and back to TabPage1, the SelectedIndex on the ComboBox is reset to 0. If I actually choose a value in the ComboBox via the dropdown list and then switch to TabPage2 and back, the selected value remains unchanged. How can I get the ComboBox.SelectedIndex to remain at -1 until a selection is made? Thanks in advance for your assistance!!!!

[Nerseus]

I'd check your code - sounds like you're doing something that's changing the index. If it's bound, it may be the data that it's bound to. Normally, when you use bound controls you *never* change the control properties - you change the dataset. To deselect something in your combobox, you'd set the corresponding value in your dataset to System.DBNull.Value (or 0, or whatever indicates a bad/unknown value for you).

 

-ners

[stuart]

Did you ever get a resolution to this.

 

I'm having a similar problem. I have a combobox (dropdownlist) bound to a datatable. In the form load event I set the selectedindex = -1. But when the form appears on the screen the selectedindex = 0 and the first item is selected.

 

I have a button that set the selectedindex = -1. However this only works if an item has NOT been selected from the dropdown. If an item has been selected from the dropdown then clicking the button causes selectedindex = 0 and the first item in the list is selected again.

 

Any ideas on how to:

a) have the form load with no item selected in the combobox (ie. selectedindex = -1 and

b) clear the combobox (ie set selectedindex back to -1) no matter the current selection of the combobox.

 

Thanks in advance.