An application must use the .NET event loop when there is a chance it might use GUI for .NET. Incorporating the .NET event loop into your ABL application is Step 4 in the following list of steps that are required to create and manage a .NET form:

1. Instantiate the form and its controls using the NEW function for classes

2. Initialize the form, together with its controls

3. Subscribe handlers to appropriate .NET events

4. Execute a .NET WAIT-FOR statement, which calls an appropriate .NET input-blocking method for the form

5. After the form closes and the WAIT-FOR statement returns, do any post-form-closing tasks, such as resource clean-up, that your application might require

For more information about blocking on .NET forms, see Use .NET classes in ABL Applications.