WinForms – Loop through a form’s controls

Forms also have a collection of controls (Controls property) that you can loop through. This is useful for when you want to do something to multiple controls and don’t want to have to manually type out code to deal with individual controls. Here’s an example of looping through a form’s top-level controls: Note: In the … Read more

WinForms – ComboBox with enum description

By default, when you load enum values into a ComboBox, it’ll show the enum names. If you want to show the enum descriptions (from the [Description] attribute) instead, and still be able to get the selected enum value, you can do the following: Generate a list of objects containing the enum value/description pairs. Set ComboBox.DataSource … Read more

System.ArgumentException: Complex DataBinding accepts as a data source either an IList or an IListSource

If you try to set a list control’s DataSource to a type it can’t handle, then you’ll get the following exception: System.ArgumentException: Complex DataBinding accepts as a data source either an IList or an IListSource. (Parameter ‘value’)at System.Windows.Forms.ListControl.set_DataSource(Object value) Note: This applies to all controls that subclass ListControl, such as ComboBox and ListBox. This is … Read more

ArgumentOutOfRangeException: InvalidArgument=Value of 0 is not valid for SelectedIndex

Problem Let’s say you’re initializing a ComboBox like this: And you get the following exception: System.ArgumentOutOfRangeException: ‘InvalidArgument=Value of ‘0’ is not valid for ‘SelectedIndex’. (Parameter ‘value’)Actual value was 0.’ You’re getting this exception because the DataSource is empty. Solution Are you expecting there to always be data? If you’re expecting there to always be data, … Read more