android - 第二个动画从屏幕顶部开始，而不是前一个动画的位置

Question

我有两个动画一个接一个地发生。第一个按预期工作，但是，第二个动画在第一个动画onAnimationEnd()调用时跳转到屏幕的最顶部。一个气球 ImageView “浮动”到屏幕的中心，它应该展开（其余部分将在稍后实现。我只是想让这部分工作）。第一个动画是纯Java，不是xml。

第二个动画的 xml (bounce.xml)：

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <scale
        android:duration="2000"
        android:fromXScale="1.0"
        android:toXScale="2.0"
        android:fromYScale="1.0"
        android:toYScale="2.0"
        android:pivotX="50%"
        android:pivotY="50%"/>
</set>    

我的 BounceInterpolator 类：

public class BounceInterpolator implements Interpolator {
    private double mAmplitude = 1;
    private double mFrequency = 10;

    BounceInterpolator(double amplitude, double frequency) {
        mAmplitude = amplitude;
        mFrequency = frequency;
    }
    public float getInterpolation(float time) {
        return (float) (-1 * Math.pow(Math.E, -time/ mAmplitude) * Math.cos(mFrequency * time) + 1);
    }
}

最后是发生这一切的课程：

public class CelebrateActivity extends AppCompatActivity {

    ImageView purple_balloon_1;
    Animation anim;
    Animation bounceAnim;
    RelativeLayout layout;
    MediaPlayer mediaPlayer;
    DisplayMetrics displayMetrics;
    static int height;

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

        displayMetrics = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
        height = displayMetrics.heightPixels;

        mediaPlayer = MediaPlayer.create(this, R.raw.first_love);
        mediaPlayer.start();

        layout = findViewById(R.id.relativeLayout);
        purple_balloon_1 = findViewById(R.id.purple_balloon_1);
        slideUp();
    }

    public void slideUp() {
        Animation slide = null;
        slide = new TranslateAnimation(0, 0, height, height / 2 - 100);
        slide.setDuration(15000);
        slide.setFillAfter(true);
        slide.setFillEnabled(true);
        purple_balloon_1.startAnimation(slide);

        bounceAnim = AnimationUtils.loadAnimation(CelebrateActivity.this, R.anim.bounce);
        BounceInterpolator interpolator = new BounceInterpolator(0.2, 20);
        bounceAnim.setInterpolator(interpolator);

        slide.setAnimationListener(new Animation.AnimationListener() {
            @Override
            public void onAnimationStart(Animation animation) {

            }

            @Override
            public void onAnimationEnd(Animation animation) {
                purple_balloon_1.startAnimation(bounceAnim); //Where the 2nd animation is supposed to start. It works, but it jumps to the top of the screen.
            }
            @Override
            public void onAnimationRepeat(Animation animation) {

            }
        });
    }
}

为什么它会跳到屏幕顶部，如何将 Y 坐标设置为 ImageView 的位置以防止说跳跃？

标签： androidandroid-animation

Answer 1

@pskink - 谢谢你的提示。我选择了 ObjectAnimator 和 AnimatorSet。我摆脱了我的 xml 文件和 BounceInterpolator 类，它在这个过程中节省了很多代码。动画现在完美运行。

再次谢谢你。

public class CelebrateActivity extends AppCompatActivity {

    ImageView purple_balloon_1;
    //Animation slide;
    //Animation grow;
    AnimatorSet animatorSet;
    RelativeLayout layout;
    MediaPlayer mediaPlayer;
    DisplayMetrics displayMetrics;
    static int height;

    public static final String TAG = "CelebrateActivity.this";

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

        displayMetrics = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
        height = displayMetrics.heightPixels;

        mediaPlayer = MediaPlayer.create(this, R.raw.first_love);
        mediaPlayer.start();

        layout = findViewById(R.id.relativeLayout);
        purple_balloon_1 = findViewById(R.id.purple_balloon_1);

        animatorSet = new AnimatorSet();
        ObjectAnimator slide = ObjectAnimator.ofFloat(purple_balloon_1, "translationY", height, height / 2);
        slide.setDuration(15000);
        ObjectAnimator growX = ObjectAnimator.ofFloat(purple_balloon_1, "scaleX", 1.5f);
        growX.setDuration(500);
        ObjectAnimator growY = ObjectAnimator.ofFloat(purple_balloon_1, "scaleY", 1.5f);
        growY.setDuration(500);

        animatorSet.playTogether(growX, growY);
        animatorSet.playSequentially(slide, growX);
        animatorSet.start();
    }
}