Android UI Framework Usage Guide

The main steps for using the Android UI framework include:

1. Define UI components in the layout file: Use an XML file to define the layout structure and UI components, including various view components (such as TextView, Button, EditText, etc.) and layout containers (such as LinearLayout, RelativeLayout, etc.).
2. Load layout file in Activity or Fragment: Use the setContentView method in the corresponding Activity or Fragment to load the layout file and display UI components on the interface.
3. Manipulating UI components using Java code: In an Activity or Fragment, obtain references to UI components defined in XML files using the findViewById method, and interact with the UI components by calling appropriate methods such as setting text content, setting click event listeners, etc.
4. Responding to user actions: By setting event listeners for UI components (such as OnClickListener, OnLongClickListener, etc.), we can handle user actions accordingly, such as displaying a Toast message when a button is clicked or verifying text input formats when entering text.
5. Adapt to different screens: By using the adaptation mechanisms provided by Android (such as using dp and sp units instead of px units, using ConstraintLayout layout, etc.), the application can display properly on different screen sizes and densities.

In general, the utilization of the Android UI framework primarily involves defining, loading, and manipulating layout files, as well as responding to user interactions. By designing layouts effectively and manipulating UI components, it is possible to create visually appealing and user-friendly Android application interfaces.