12 - QtDesigner - Provides classes to create your own custom widget plugins for Qt Designer and classes to access Qt Designer components
QAbstractExtensionFactory - Interface for extension factories in Qt Designer
QAbstractExtensionManager - Interface for extension managers in Qt Designer
QAbstractFormBuilder - Default implementation for classes that create user interfaces at run-time
QDesignerActionEditorInterface - Allows you to change the focus of Qt Designer‘s action editor
QDesignerContainerExtension - Allows you to add pages to a custom multi-page container in Qt Designer‘s workspace
QDesignerCustomWidgetCollectionInterface - Allows you to include several custom widgets in one single library
QDesignerCustomWidgetInterface - Enables Qt Designer to access and construct custom widgets
QDesignerDynamicPropertySheetExtension - Allows you to manipulate a widget‘s dynamic properties in Qt Designer‘s property editor
QDesignerFormEditorInterface - Allows you to access Qt Designer‘s various components
QDesignerFormWindowCursorInterface - Allows you to query and modify a form window‘s widget selection, and in addition modify the properties of all the form‘s widgets
QDesignerFormWindowInterface - Allows you to query and manipulate form windows appearing in Qt Designer‘s workspace
QDesignerFormWindowManagerInterface - Allows you to manipulate the collection of form windows in Qt Designer, and control Qt Designer‘s form editing actions
QDesignerMemberSheetExtension - Allows you to manipulate a widget‘s member functions which is displayed when configuring connections using Qt Designer‘s mode for editing signals and slots
QDesignerObjectInspectorInterface - Allows you to change the focus of Qt Designer‘s object inspector
QDesignerPropertyEditorInterface - Allows you to query and manipulate the current state of Qt Designer‘s property editor
QDesignerPropertySheetExtension - Allows you to manipulate a widget‘s properties which is displayed in Qt Designer‘s property editor
QDesignerTaskMenuExtension - Allows you to add custom menu entries to Qt Designer‘s task menu
QDesignerWidgetBoxInterface - Allows you to control the contents of Qt Designer‘s widget box
QExtensionFactory - Allows you to create a factory that is able to make instances of custom extensions in Qt Designer
QExtensionManager - Extension management facilities for Qt Designer
QFormBuilder - Used to dynamically construct user interfaces from UI files at run-time
原文：http://www.cnblogs.com/stycpp-2016/p/6382198.html