旋转时保留TextView中的文本

@Override
protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    outState.putString("textViewText", textView.getText().toString());
}

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
    super.onRestoreInstanceState(savedInstanceState);
    String savedText = savedInstanceState.getString("textViewText");
    textView.setText(savedText);
}

implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:2.5.1"

public class MyViewModel extends ViewModel {
    private MutableLiveData<String> text = new MutableLiveData<>();

    public LiveData<String> getText() {
        return text;
    }

    public void setText(String value) {
        text.setValue(value);
    }
}

public class MainActivity extends AppCompatActivity {
    private MyViewModel viewModel;
    private TextView textView;

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

        textView = findViewById(R.id.textView);
        viewModel = new ViewModelProvider(this).get(MyViewModel.class);

        viewModel.getText().observe(this, new Observer<String>() {
            @Override
            public void onChanged(String text) {
                textView.setText(text);
            }
        });
    }

    // 在需要更新文本的地方调用
    private void updateText(String newText) {
        viewModel.setText(newText);
    }
}