java - 改进 Java 代码，使其在 Android 上执行得更快

Question

我的 Java 代码在 Android 设备中执行速度非常慢。我想这是因为我在一个类上完成了这一切。我需要一些关于如何改进我的代码的建议，也许可以通过将其划分为不同的类来实现。你会怎么做？

public class MainActivity extends AppCompatActivity {
    View white;
    Animation downtoup;

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

        //Remove notification bar
        View decorView = getWindow().getDecorView();
        int uiOptions = View.SYSTEM_UI_FLAG_FULLSCREEN;
        decorView.setSystemUiVisibility(uiOptions);

        //MovingScanSquare
        white = findViewById(R.id.white);
        downtoup = AnimationUtils.loadAnimation(this, R.anim.downtoup);

        white.setVisibility(View.VISIBLE);
        downtoup = new TranslateAnimation(
                TranslateAnimation.ABSOLUTE, 0f,
                TranslateAnimation.ABSOLUTE, 0f,
                TranslateAnimation.RELATIVE_TO_PARENT, 1.1f,
                TranslateAnimation.RELATIVE_TO_PARENT, 0.f);
        downtoup.setDuration(2200);
        downtoup.setRepeatCount(-1);
        downtoup.setRepeatMode(Animation.REVERSE);
        downtoup.setInterpolator(new LinearInterpolator());
        white.setAnimation(downtoup);


        //movingscreen
        final ImageView backgroundOne =  findViewById(R.id.background_one);
        final ImageView backgroundTwo =  findViewById(R.id.background_two);

        final ValueAnimator animator = ValueAnimator.ofFloat(0.0f, -1.0f);
        animator.setRepeatCount(ValueAnimator.INFINITE);
        animator.setInterpolator(new LinearInterpolator());
        animator.setDuration(3000L);
        animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
            @Override
            public void onAnimationUpdate(ValueAnimator animation) {
                final float progress = (float) animation.getAnimatedValue();
                final float width = backgroundOne.getWidth();
                final float translationX = width * progress;
                backgroundOne.setTranslationX(translationX);
                backgroundTwo.setTranslationX(translationX + width);
            }
        });
        animator.start();
    }
}

Answer 1

将代码拆分为不同的类不会让您走得太远。如果不对其进行分析，就很难说出那里发生了什么。使用分析工具之一，VisualVM例如，这样做。

监视您的应用程序，找出哪一行代码花费了太多时间并尝试对其进行优化。