CreateCustomForm

function CreateCustomForm: TSetupForm;

Creates a form. The form is empty by default; you have to create your own controls afterward and place them on the form (by setting their Parent properties to the TSetupForm instance returned by this function).

You should call this function instead of creating TForm or TSetupForm instances directly. This function automatically initializes the font and other properties of the created form to be like Setup's other dialogs.

The [LangOptions] section's DialogFontName and DialogFontSize directives determine the font used by the form and, by default, any child controls created on the form.

See CodeClasses.iss for an example.