android - 暂停时自定义循环显示转换结果为 "java.lang.UnsupportedOperationException"？

Question

我创建了一个自定义循环显示过渡，用作 Activity 进入过渡的一部分(具体来说，我通过调用 Window#setEnterTransition() 将过渡设置为窗口的进入过渡):

public class CircularRevealTransition extends Visibility {
    private final Rect mStartBounds = new Rect();

    /**
     * Use the view's location as the circular reveal's starting position.
     */
    public CircularRevealTransition(View v) {
        int[] loc = new int[2];
        v.getLocationInWindow(loc);
        mStartBounds.set(loc[0], loc[1], loc[0] + v.getWidth(), loc[1] + v.getHeight());
    }

    @Override
    public Animator onAppear(ViewGroup sceneRoot, final View v, TransitionValues startValues, TransitionValues endValues) {
        if (endValues == null) {
            return null;
        }
        int halfWidth = v.getWidth() / 2;
        int halfHeight = v.getHeight() / 2;
        float startX = mStartBounds.left + mStartBounds.width() / 2 - halfWidth;
        float startY = mStartBounds.top + mStartBounds.height() / 2 - halfHeight;
        float endX = v.getTranslationX();
        float endY = v.getTranslationY();
        v.setTranslationX(startX);
        v.setTranslationY(startY);

        // Create a circular reveal animator to play behind a shared
        // element during the Activity Transition.
        Animator revealAnimator = ViewAnimationUtils.createCircularReveal(v, halfWidth, halfHeight, 0f,
                FloatMath.sqrt(halfWidth * halfHeight + halfHeight * halfHeight));
        revealAnimator.addListener(new AnimatorListenerAdapter() {
            @Override
            public void onAnimationEnd(Animator animation) {
                // Set the view's visibility to VISIBLE to prevent the
                // reveal from "blinking" at the end of the animation.
                v.setVisibility(View.VISIBLE);
            }
        });

        // Translate the circular reveal into place as it animates.
        PropertyValuesHolder pvhX = PropertyValuesHolder.ofFloat("translationX", startX, endX);
        PropertyValuesHolder pvhY = PropertyValuesHolder.ofFloat("translationY", startY, endY);
        Animator translationAnimator = ObjectAnimator.ofPropertyValuesHolder(v, pvhX, pvhY);

        AnimatorSet anim = new AnimatorSet();
        anim.setInterpolator(getInterpolator());
        anim.playTogether(revealAnimator, translationAnimator);
        return anim;
    }
}

这正常工作。但是，当我在转换过程中单击“后退按钮”时，出现以下异常:

Process: com.adp.activity.transitions, PID: 13800
java.lang.UnsupportedOperationException
        at android.view.RenderNodeAnimator.pause(RenderNodeAnimator.java:251)
        at android.animation.AnimatorSet.pause(AnimatorSet.java:472)
        at android.transition.Transition.pause(Transition.java:1671)
        at android.transition.TransitionSet.pause(TransitionSet.java:483)
        at android.app.ActivityTransitionState.startExitBackTransition(ActivityTransitionState.java:269)
        at android.app.Activity.finishAfterTransition(Activity.java:4672)
        at com.adp.activity.transitions.DetailsActivity.finishAfterTransition(DetailsActivity.java:167)
        at android.app.Activity.onBackPressed(Activity.java:2480)

我收到此错误有任何具体原因吗？应该如何避免？

Answer 1

您将需要创建一个 Animator 的子类来忽略对 pause() 和 resume() 的调用以避免此异常.

有关更多详细信息，我刚刚在下面完成了有关此主题的帖子:

• 第 1 部分: http://halfthought.wordpress.com/2014/11/07/reveal-transition/
• 第 2 部分: https://halfthought.wordpress.com/2014/12/02/reveal-activity-transitions/