Set Default WinForms ComboBox Selection

There are two ways to set a default selected item in a WinForm dropdown list.

1. Set the default selected item when the form is loaded:
   When the form is loaded, you can use code to set the SelectedIndex property of a dropdown list to choose the default selected item. For example, if you want to default select the first item, you can use the following code:

comboBox1.SelectedIndex = 0;

1. When designing, set the default selected item:
   When designing, you can use the interface designer to set the SelectedItem property of the dropdown list to choose the default selected item. Find the SelectedItem property in the property panel and select the item you want to be default.

The default selected item in a WinForm drop-down list can be achieved using the above two methods.