android mvvm模板代码

以下是一个简单的Android MVVM模板代码：

Model类：

public class User {
    private String name;
    private String email;

    public User(String name, String email) {
        this.name = name;
        this.email = email;
    }

    public String getName() {
        return name;
    }

    public String getEmail() {
        return email;
    }
}

ViewModel类：

public class UserViewModel extends ViewModel {
    private MutableLiveData<User> userLiveData;

    public LiveData<User> getUserLiveData() {
        if (userLiveData == null) {
            userLiveData = new MutableLiveData<>();
            loadUser();
        }
        return userLiveData;
    }

    private void loadUser() {
        // 从网络或数据库中获取User信息
        User user = new User("Tom", "tom@example.com");
        userLiveData.setValue(user);
    }
}

View类：

public class MainActivity extends AppCompatActivity {
    private TextView nameTextView;
    private TextView emailTextView;
    private ProgressBar progressBar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        nameTextView = findViewById(R.id.nameTextView);
        emailTextView = findViewById(R.id.emailTextView);
        progressBar = findViewById(R.id.progressBar);

        UserViewModel userViewModel = new ViewModelProvider(this).get(UserViewModel.class);
        userViewModel.getUserLiveData().observe(this, user -> {
            // 更新UI显示
            nameTextView.setText(user.getName());
            emailTextView.setText(user.getEmail());
            progressBar.setVisibility(View.GONE);
        });
    }
}

此模板代码展示了一个简单的MVVM架构，其中Model类为User，ViewModel类为UserViewModel，View类为MainActivity。通过ViewModel的getUserLiveData()方法获取LiveData对象，当数据更新时，LiveData会自动通知View更新UI显示。