In many applications, the image that is displayed is not determined statically like it is in this example. For example, the image to display might be determined by something that the user clicks.
If you need to be able to choose the image to display programmatically, you can write your own custom code to access and display resources. The IDE prevents you from writing code directly in the Source view’s “guarded blocks” that contain code generated by the GUI Builder. However, you can insert code in the guarded blocks through property editors that you can access through the Properties window. Using the property editors in this manner ensures that your custom code is not lost when you make design changes in the GUI Builder.