如何在activites中停止循环，同时处理默认的屏幕导航返回？

public class MyActivity extends AppCompatActivity {
    private boolean isRunning = true;

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

        // 主循环
        while (isRunning) {
            // 执行需要重复执行的代码块
            // ...
        }
    }

    @Override
    public void onBackPressed() {
        // 处理默认的屏幕导航返回
        isRunning = false;
        super.onBackPressed();
    }
}