Question

我正在尝试使用AnimationDrawable为一组图像设置动画。用户应该能够通过单击按钮暂停/恢复动画。我正在使用setVisible(boolean visible, boolean restart)这样做。不完全确定我是否正确理解文档，但每次按下暂停时，动画都从头开始。

有没有办法从同一帧恢复动画？

来自AnimationDrawable API：

...如果重启为false，则drawable将从最近的帧恢复

要明确：

activityAnimation.setVisible(false, false);应该停止动画。

activityAnimation.setVisible(true, false);应该从同一帧恢复动画（它没有）。

这是我的代码：

动画start()在onWindowFocusChanged中调用。

动画和按钮在onCreate：

中创建

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

    ImageView activityImage = (ImageView) findViewById(R.id.activity_image);
    activityImage.setBackgroundResource(R.drawable.anim);
    activityAnimation = (AnimationDrawable) activityImage.getBackground();

    ....
    b.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            ImageButton b = (ImageButton) v;
            if ((Integer)b.getTag() == R.drawable.pause) {
                b.setImageResource(R.drawable.play);
                b.setTag(R.drawable.play);
                activityAnimation.setVisible(false, false);
            } else {
                b.setImageResource(R.drawable.pause);
                b.setTag(R.drawable.pause);
                activityAnimation.setVisible(true, false);
            }
        }
    });...
}

这是XML文件的内容

<?xml version="1.0" encoding="utf-8"?>
<animation-list xmlns:android="http://schemas.android.com/apk/res/android"
    android:oneshot="false">

    <item android:drawable="@drawable/one" android:duration="1000" />
    <item android:drawable="@drawable/two" android:duration="1000" />
    <item android:drawable="@drawable/three" android:duration="1000" />
    <item android:drawable="@drawable/four" android:duration="1000" />

</animation-list>

我已经注意到其中一些旧帖子，但没有答案。

How to reset AnimationDrawable（本期的另一面）

How do I pause frame animation using AnimationDrawable? [Closed]

Answer 1

由于我在屏幕上也需要一个计时器，我的答案就是创建一个runnable每秒替换ImageView背景。

以下是一般概念：

创建runnable，ImageView和少数助手：

ImageView exImage = null;

long startTime = 0;
long pauseTime = 0;
long pauseStartTime = 0;

List<Integer> animList = new ArrayList<>();
int animIt = 0;        

Handler timerHandler = new Handler();
Runnable timerRunnable = new Runnable() {
    @Override
    public void run() {

        long millis = System.currentTimeMillis() - startTime - pauseTime;
        double dSecs = (double) (millis / 100);
        int pace = 10;

        if (dSecs % pace == 0.0 && !animList.isEmpty()) {
            animIt = (animIt == animList.size() - 1) ? 0 : animIt + 1;
            exImage.setBackgroundResource(animList.get(animIt));
        }
        timerHandler.postDelayed(this, 100);
    }
};

在OnCreate绑定暂停和播放按钮，触发计时器并设置第一个ImageView

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

    // Set the image view
    exImage = (ImageView) findViewById(R.id.image_zero);
    exImage.setBackgroundResource(R.drawable.fe_0);

    // Start the timer
    timerHandler.postDelayed(timerRunnable, 0);

    // Bind the buttons
    ImageButton pp = (ImageButton) findViewById(R.id.button_play_pause_toggle);
    pp.setImageResource(R.drawable.pause);
    pp.setTag(R.drawable.pause);

    pp.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            ImageButton pp = (ImageButton) v;
            //Pause
            if ((Integer) pp.getTag() == R.drawable.pause) {
                pauseStartTime = System.currentTimeMillis();
                timerHandler.removeCallbacks(timerRunnable);
            } else { // Resume
                pauseTime += System.currentTimeMillis() - pauseStartTime;
                timerHandler.postDelayed(timerRunnable, 0);
            }
        }
    });
}

Answer 2

要暂停和恢复AnimationDrawable，只需对其进行自定义并仅使用一个变量即可处理。

class CustomAnimationDrawable1() : AnimationDrawable() {

private var finished = false
private var animationFinishListener: AnimationFinishListener? = null
private var isPause = false
private var currentFrame = 0

fun setFinishListener(animationFinishListener: AnimationFinishListener?) {
    this.animationFinishListener = animationFinishListener
}

interface AnimationFinishListener {
    fun onAnimationFinished()
}


override fun selectDrawable(index: Int): Boolean {
    val ret = if (isPause) {
        super.selectDrawable(currentFrame)
    } else {
        super.selectDrawable(index)
    }

    if (!isPause) {
        currentFrame = index
        if (index == numberOfFrames - 1) {
            if (!finished && ret && !isOneShot) {
                finished = true
                if (animationFinishListener != null) animationFinishListener!!.onAnimationFinished()
            }
        }
    }
    return ret
}

fun pause() {
    isPause = true
}

fun resume() {
    isPause = false
}

}

暂停AnimationDrawable并从同一帧

2 个答案: