popwindow 动画取消奔溃报错java.lang.NullPointerException ViewRootImpl.drawAccessibilityFocusedDrawable

现在APP中用到popwindow的地方很多，为了美化体验效果，很多动画的展示和取消都加上了动画效果；下面我就来说下我遇到的问题以及解决的方法；

cancelAnimation.addAnimation(new AlphaAnimation(1.0f, 0.0f));cancelAnimation.addAnimation(new ScaleAnimation(1, 1, 1, -1));cancelAnimation.setDuration(executeTime);cancelAnimation.setAnimationListener(new Animation.AnimationListener() {    @Override    public void onAnimationStart(Animation animation) {        mScrollView.setVisibility(View.VISIBLE);    }    @Override    public void onAnimationEnd(Animation animation) {        mScrollView.setVisibility(View.GONE);
        dismiss();
    }    @Override    public void onAnimationRepeat(Animation animation) {    }});

上面我是实现了动画延伸和渐变来取消popwindow，在动画结束回调dismiss();

在Android 4.4以上是不会出现任何问题；但是在Android 4.1左右的版本就会在取消是奔溃：

java.lang.NullPointerException
#5367 09-20 03:38:07.99917478 ECrashReport         at android.view.ViewRootImpl.drawAccessibilityFocusedDrawableIfNeeded(ViewRootImpl.java:2596)
#5368 09-20 03:38:07.99917478 ECrashReport         at android.view.ViewRootImpl.onHardwarePostDraw(ViewRootImpl.java:2183)
#5369 09-20 03:38:07.99917478 ECrashReport         at android.view.HardwareRenderer$GlRenderer.draw(HardwareRenderer.java:1233)
#5370 09-20 03:38:07.99917478 ECrashReport         at android.view.ViewRootImpl.draw(ViewRootImpl.java:2420)
#5371 09-20 03:38:07.99917478 ECrashReport         at android.view.ViewRootImpl.performDraw(ViewRootImpl.java:2274)

查看网上说的是popwindow调用dismiss()方法时报错；我理解为时在动画结束回调时Android4.1版本的是在子线程回调；

所以在调用dismiss();时我们加上handle试下让它在主线程执行；

cancelAnimation.addAnimation(new AlphaAnimation(1.0f, 0.0f));cancelAnimation.addAnimation(new ScaleAnimation(1, 1, 1, -1));cancelAnimation.setDuration(executeTime);cancelAnimation.setAnimationListener(new Animation.AnimationListener() {    @Override    public void onAnimationStart(Animation animation) {        mScrollView.setVisibility(View.VISIBLE);    }    @Override    public void onAnimationEnd(Animation animation) {        mScrollView.setVisibility(View.GONE);        new Handler().post(new Runnable() {            @Override            public void run() {                dismiss();            }        });    }    @Override    public void onAnimationRepeat(Animation animation) {    }});

果真加了之后再Android 4.1的手机上就不在出现奔溃了