Android AnimationDrawable 并知道动画何时结束

Android AnimationDrawable and knowing when animation ends

提问by LostDroid

I want to do an animation with several image-files, and for this the AnimationDrawable works very well. However, I need to know when the animation starts and when it ends (i.e add a listener like the Animation.AnimationListener). After having searched for answers, I'm having a bad feeling the AnimationDrawable does not support listeners..

我想用几个图像文件制作动画，为此 AnimationDrawable 效果很好。但是，我需要知道动画何时开始和何时结束（即添加一个像 Animation.AnimationListener 这样的监听器）。搜索答案后，我有一种不好的感觉 AnimationDrawable 不支持听众..

Does anyone know how to create a frame-by-frame image animation with a listener on Android?

有谁知道如何使用 Android 上的侦听器创建逐帧图像动画？

回答by Ricky

After doing some reading, I came up with this solution. I'm still surprised there isn't a listener as part of the AnimationDrawableobject, but I didn't want to pass callbacks back and forward so instead I created an abstract class which raises an onAnimationFinish()method. I hope this helps someone.

在做了一些阅读之后，我想出了这个解决方案。我仍然很惊讶没有侦听器作为AnimationDrawable对象的一部分，但我不想来回传递回调，所以我创建了一个抽象类，它引发了一个onAnimationFinish()方法。我希望这可以帮助别人。

The custom animation drawable class:

自定义动画可绘制类：

public abstract class CustomAnimationDrawableNew extends AnimationDrawable {

    /** Handles the animation callback. */
    Handler mAnimationHandler;

    public CustomAnimationDrawableNew(AnimationDrawable aniDrawable) {
        /* Add each frame to our animation drawable */
        for (int i = 0; i < aniDrawable.getNumberOfFrames(); i++) {
            this.addFrame(aniDrawable.getFrame(i), aniDrawable.getDuration(i));
        }
    }

    @Override
    public void start() {
        super.start();
        /*
         * Call super.start() to call the base class start animation method.
         * Then add a handler to call onAnimationFinish() when the total
         * duration for the animation has passed
         */
        mAnimationHandler = new Handler();
        mAnimationHandler.post(new Runnable() {
            @Override
            public void run() {
                onAnimationStart();
            }  
        };
        mAnimationHandler.postDelayed(new Runnable() {
            @Override
            public void run() {
                onAnimationFinish();
            }
        }, getTotalDuration());

    }

    /**
     * Gets the total duration of all frames.
     * 
     * @return The total duration.
     */
    public int getTotalDuration() {

        int iDuration = 0;

        for (int i = 0; i < this.getNumberOfFrames(); i++) {
            iDuration += this.getDuration(i);
        }

        return iDuration;
    }

    /**
     * Called when the animation finishes.
     */
    public abstract void onAnimationFinish();
   /**
     * Called when the animation starts.
     */
    public abstract void onAnimationStart();
}

To use this class:

要使用这个类：

    ImageView iv = (ImageView) findViewById(R.id.iv_testing_testani);

    iv.setOnClickListener(new OnClickListener() {
        public void onClick(final View v) {

            // Pass our animation drawable to our custom drawable class
            CustomAnimationDrawableNew cad = new CustomAnimationDrawableNew(
                    (AnimationDrawable) getResources().getDrawable(
                            R.drawable.anim_test)) {
                @Override
                void onAnimationStart() {
                    // Animation has started...
                }

                @Override
                void onAnimationFinish() {
                    // Animation has finished...
                }
            };

            // Set the views drawable to our custom drawable
            v.setBackgroundDrawable(cad);

            // Start the animation
            cad.start();
        }
    });

回答by benhylau

I needed to know when my one-shot AnimationDrawable completes, without having to subclass AnimationDrawable since I must set the animation-list in XML. I wrote this class and tested it on Gingerbread and ICS. It can easily be extended to give a callback on each frame.

我需要知道我的一次性 AnimationDrawable 何时完成，而不必子类化 AnimationDrawable，因为我必须在 XML 中设置动画列表。我编写了这个类并在 Gingerbread 和 ICS 上对其进行了测试。它可以很容易地扩展为在每一帧上进行回调。

/**
 * Provides a callback when a non-looping {@link AnimationDrawable} completes its animation sequence. More precisely,
 * {@link #onAnimationComplete()} is triggered when {@link View#invalidateDrawable(Drawable)} has been called on the
 * last frame.
 * 
 * @author Benedict Lau
 */
public abstract class AnimationDrawableCallback implements Callback {

    /**
     * The last frame of {@link Drawable} in the {@link AnimationDrawable}.
     */
    private Drawable mLastFrame;

    /**
     * The client's {@link Callback} implementation. All calls are proxied to this wrapped {@link Callback}
     * implementation after intercepting the events we need.
     */
    private Callback mWrappedCallback;

    /**
     * Flag to ensure that {@link #onAnimationComplete()} is called only once, since
     * {@link #invalidateDrawable(Drawable)} may be called multiple times.
     */
    private boolean mIsCallbackTriggered = false;

    /**
     * 
     * @param animationDrawable
     *            the {@link AnimationDrawable}.
     * @param callback
     *            the client's {@link Callback} implementation. This is usually the {@link View} the has the
     *            {@link AnimationDrawable} as background.
     */
    public AnimationDrawableCallback(AnimationDrawable animationDrawable, Callback callback) {
        mLastFrame = animationDrawable.getFrame(animationDrawable.getNumberOfFrames() - 1);
        mWrappedCallback = callback;
    }

    @Override
    public void invalidateDrawable(Drawable who) {
        if (mWrappedCallback != null) {
            mWrappedCallback.invalidateDrawable(who);
        }

        if (!mIsCallbackTriggered && mLastFrame != null && mLastFrame.equals(who.getCurrent())) {
            mIsCallbackTriggered = true;
            onAnimationComplete();
        }
    }

    @Override
    public void scheduleDrawable(Drawable who, Runnable what, long when) {
        if (mWrappedCallback != null) {
            mWrappedCallback.scheduleDrawable(who, what, when);
        }
    }

    @Override
    public void unscheduleDrawable(Drawable who, Runnable what) {
        if (mWrappedCallback != null) {
            mWrappedCallback.unscheduleDrawable(who, what);
        }
    }

    //
    // Public methods.
    //

    /**
     * Callback triggered when {@link View#invalidateDrawable(Drawable)} has been called on the last frame, which marks
     * the end of a non-looping animation sequence.
     */
    public abstract void onAnimationComplete();
}

Here is how to use it.

这是如何使用它。

AnimationDrawable countdownAnimation = (AnimationDrawable) mStartButton.getBackground();
countdownAnimation.setCallback(new AnimationDrawableCallback(countdownAnimation, mStartButton) {
    @Override
    public void onAnimationComplete() {
        // TODO Do something.
    }
});
countdownAnimation.start();

回答by Ruslan Yanchyshyn

Animation end can be easily tracked by overriding selectDrawable method in AnimationDrawable class. Complete code is the following:

通过覆盖 AnimationDrawable 类中的 selectDrawable 方法，可以轻松跟踪动画结束。完整代码如下：

public class AnimationDrawable2 extends AnimationDrawable
{
    public interface IAnimationFinishListener
    {
        void onAnimationFinished();
    }

    private boolean finished = false;
    private IAnimationFinishListener animationFinishListener;

    public IAnimationFinishListener getAnimationFinishListener()
    {
        return animationFinishListener;
    }

    public void setAnimationFinishListener(IAnimationFinishListener animationFinishListener)
    {
        this.animationFinishListener = animationFinishListener;
    }

    @Override
    public boolean selectDrawable(int idx)
    {
        boolean ret = super.selectDrawable(idx);

        if ((idx != 0) && (idx == getNumberOfFrames() - 1))
        {
            if (!finished)
            {
                finished = true;
                if (animationFinishListener != null) animationFinishListener.onAnimationFinished();
            }
        }

        return ret;
    }
}

回答by hitch45

I used a recursive function that checks to see if the current frame is the last frame every timeBetweenChecksmilliseconds.

我使用了一个递归函数来检查当前帧是否是每timeBetweenChecks毫秒的最后一帧。

private void checkIfAnimationDone(AnimationDrawable anim){
    final AnimationDrawable a = anim;
    int timeBetweenChecks = 300;
    Handler h = new Handler();
    h.postDelayed(new Runnable(){
        public void run(){
            if (a.getCurrent() != a.getFrame(a.getNumberOfFrames() - 1)){
                checkIfAnimationDone(a);
            } else{
                Toast.makeText(getApplicationContext(), "ANIMATION DONE!", Toast.LENGTH_SHORT).show();
            }
        }
    }, timeBetweenChecks);
}

回答by Kingpin

A timer is a bad choice for this because you will get stuck trying to execute in a non UI thread like HowsItStack said. For simple tasks you can just use a handler to call a method at a certain interval. Like this:

计时器是一个糟糕的选择，因为你会像 HowsItStack 所说的那样尝试在非 UI 线程中执行。对于简单的任务，您可以仅使用处理程序以特定时间间隔调用方法。像这样：

handler.postDelayed(runnable, duration of your animation); //Put this where you start your animation

private Handler handler = new Handler();

private Runnable runnable = new Runnable() {

    public void run() {
        handler.removeCallbacks(runnable)
        DoSomethingWhenAnimationEnds();

    }

};

removeCallbacks assures this only executes once.

removeCallbacks 确保这只执行一次。

回答by kazimad

if you want to impliment your animation in adapter - should use next public class CustomAnimationDrawable extends AnimationDrawable {

如果你想在适配器中实现你的动画 - 应该使用下一个公共类 CustomAnimationDrawable extends AnimationDrawable {

/**
 * Handles the animation callback.
 */
Handler mAnimationHandler;
private OnAnimationFinish onAnimationFinish;

public void setAnimationDrawable(AnimationDrawable aniDrawable) {
    for (int i = 0; i < aniDrawable.getNumberOfFrames(); i++) {
        this.addFrame(aniDrawable.getFrame(i), aniDrawable.getDuration(i));
    }
}

public void setOnFinishListener(OnAnimationFinish onAnimationFinishListener) {
    onAnimationFinish = onAnimationFinishListener;
}


@Override
public void stop() {
    super.stop();
}

@Override
public void start() {
    super.start();
    mAnimationHandler = new Handler();
    mAnimationHandler.postDelayed(new Runnable() {

        public void run() {
            if (onAnimationFinish != null)
                onAnimationFinish.onFinish();
        }
    }, getTotalDuration());

}

/**
 * Gets the total duration of all frames.
 *
 * @return The total duration.
 */
public int getTotalDuration() {
    int iDuration = 0;
    for (int i = 0; i < this.getNumberOfFrames(); i++) {
        iDuration += this.getDuration(i);
    }
    return iDuration;
}

/**
 * Called when the animation finishes.
 */
public interface OnAnimationFinish {
    void onFinish();
}

}

}

and implementation in RecycleView Adapter

并在 RecycleView Adapter 中实现

@Override
public void onBindViewHolder(PlayGridAdapter.ViewHolder holder, int position) {
    final Button mButton = holder.button;
    mButton.setBackgroundResource(R.drawable.animation_overturn);
    final CustomAnimationDrawable mOverturnAnimation = new CustomAnimationDrawable();
    mOverturnAnimation.setAnimationDrawable((AnimationDrawable) mContext.getResources().getDrawable(R.drawable.animation_overturn));
    mOverturnAnimation.setOnFinishListener(new CustomAnimationDrawable.OnAnimationFinish() {
        @Override
        public void onFinish() {
           // your perform
        }
    });

    mButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(final View v) {
                mOverturnAnimation.start();
        }
    });
}

回答by ban-geoengineering

I also like Ruslan's answer, but I had to make a couple of changes in order to get it to do what I required.

我也喜欢 Ruslan 的回答，但我必须进行一些更改才能使其达到我的要求。

In my code, I have got rid of Ruslan's finishedflag, and I have also utilised the boolean returned by super.selectDrawable().

在我的代码中，我摆脱了 Ruslan 的finished标志，并且我还使用了super.selectDrawable().

Here's my code:

这是我的代码：

class AnimationDrawableWithCallback extends AnimationDrawable {

    interface IAnimationFinishListener {
        void onAnimationChanged(int index, boolean finished);
    }

    private IAnimationFinishListener animationFinishListener;

    public IAnimationFinishListener getAnimationFinishListener() {
        return animationFinishListener;
    }

    void setAnimationFinishListener(IAnimationFinishListener animationFinishListener) {
        this.animationFinishListener = animationFinishListener;
    }

    @Override
    public boolean selectDrawable(int index) {

        boolean drawableChanged = super.selectDrawable(index);

        if (drawableChanged && animationFinishListener != null) {
            boolean animationFinished = (index == getNumberOfFrames() - 1);
            animationFinishListener.onAnimationChanged(index, animationFinished);
        }

        return drawableChanged;

    }

}

And here is an example of how to implement it...

这是一个如何实现它的例子......

public class MyFragment extends Fragment implements AnimationDrawableWithCallback.IAnimationFinishListener {

    @Override
    public void onAnimationChanged(int index, boolean finished) {

        // Do whatever you need here

    }

}

If you only want to know when the first cycle of animation has completed, then you can set a boolean flag in your fragment/activity.

如果您只想知道动画的第一个循环何时完成，那么您可以在片段/活动中设置一个布尔标志。

回答by mochadwi

You can use registerAnimationCallbackto check your animation start and end.

您可以使用registerAnimationCallback来检查动画的开始和结束。

Here's the snippet code:

这是片段代码：

// ImageExt.kt
fun ImageView.startAnim(block: () -> Unit) {
    (drawable as Animatable).apply {
        registerAnimationCallback(
                drawable,
                object : Animatable2Compat.AnimationCallback() {
                    override fun onAnimationStart(drawable: Drawable?) {
                        block.invoke()
                        isClickable = false
                        isEnabled = false
                    }

                    override fun onAnimationEnd(drawable: Drawable?) {
                        isClickable = true
                        isEnabled = true
                    }
        })
    }.run { start() }
}

// Fragment.kt
imageView.startAnim {
    // do something after the animation ends here
}

The purpose of the ImageExt was to disable after animation start (on progress) to prevent user spamming the animation and resulting in the broken / wrong vector shown.

ImageExt 的目的是在动画开始（进行中）后禁用，以防止用户向动画发送垃圾邮件并导致显示的矢量损坏/错误。

With frame-by-frame, you might want to trigger another ImageView like this.

对于逐帧，您可能想要触发另一个这样的 ImageView。

// Animation.kt
iv1.startAnim {
    iv2.startAnim {
        // iv3, etc
    }
}

But the above solutions looks ugly. If anyone has a better approach, please comment below, or edit this answer directly.

但上述解决方案看起来很难看。如果有人有更好的方法，请在下面发表评论，或直接编辑此答案。

回答by lalalei

I guess your Code does not work, because you try to modify a View from a non-UI-Thread. Try to call runOnUiThread(Runnable) from your Activity. I used it to fade out a menu after an animation for this menu finishes. This code works for me:

我猜您的代码不起作用，因为您尝试从非 UI 线程修改视图。尝试从您的活动中调用 runOnUiThread(Runnable)。在此菜单的动画完成后，我用它来淡出菜单。这段代码对我有用：

Animation ani =  AnimationUtils.loadAnimation(YourActivityNameHere.this, R.anim.fadeout_animation);
menuView.startAnimation(ani);

// Use Timer to set visibility to GONE after the animation finishes.            
TimerTask timerTask = new TimerTask(){
    @Override
    public void run() {
        YourActivityNameHere.this.runOnUiThread(new Runnable(){
            @Override
            public void run() {
                menuView.setVisibility(View.GONE);
            }
        });}};
timer.schedule(timerTask, ani.getDuration());

回答by Illegal Argument

I had the same problem when I had to implement a button click after animation stopped. I checked the current frame and the lastframe of animation drawable to know when an animation is stopped. Note that it is not a listener but just a way to know it animation has stopped.

当我不得不在动画停止后实现按钮点击时，我遇到了同样的问题。我检查了可绘制动画的当前帧和最后一帧，以了解动画何时停止。请注意，它不是侦听器，而只是一种知道动画已停止的方法。

if (spinAnimation.getCurrent().equals(
                    spinAnimation.getFrame(spinAnimation
                            .getNumberOfFrames() - 1))) {
                Toast.makeText(MainActivity.this, "finished",
                        Toast.LENGTH_SHORT).show();
            } else {
                Toast.makeText(MainActivity.this, "Not finished",
                        Toast.LENGTH_SHORT).show();
            }