小编Tje*_*rkW的帖子

我想在从一个Activity转到另一个Activity时设置共享元素转换.

第一个Activity有一个包含项目的RecyclerView.单击某个项目时,该项目应为新活动设置动画.

所以我在最终活动视图上设置了android:transitionName ="item",以及recycleler-view项目视图.

我还在进行下一个活动时使用此代码:

this.startActivity(intent, ActivityOptions.makeSceneTransitionAnimation(this, itemView, "boomrang_item").toBundle());

单击某个项目时,它会正确转换并显示新视图.真的很好.但是当我点击后退按钮时.有时它工作正常,但大多数时候我的活动崩溃与下面的堆栈跟踪:

   java.lang.NullPointerException: Attempt to invoke virtual method 'void android.view.ViewGroup.transformMatrixToGlobal(android.graphics.Matrix)' on a null object reference
            at android.view.GhostView.calculateMatrix(GhostView.java:95)
            at android.app.ActivityTransitionCoordinator$GhostViewListeners.onPreDraw(ActivityTransitionCoordinator.java:845)
            at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:847)
            at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1956)
            at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1054)
            at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5779)
            at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767)
            at android.view.Choreographer.doCallbacks(Choreographer.java:580)
            at android.view.Choreographer.doFrame(Choreographer.java:550)
            at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753)
            at android.os.Handler.handleCallback(Handler.java:739)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)

我究竟做错了什么？它看起来像android 5中的一个bug

我有一个带有WebView的应用程序.当Activity暂停(onPause)时,我调用适当的webview.onPause和webview.stopTimers,这些与Activity.onResume方法中的webview.onResume和webview.resumeTimers平衡.

现在,当我在webview中加载www.google.com,然后将应用程序放在后台时,它仍将使用高达30%的CPU!这太过分了.

我执行了方法分析,发现WebViewCoreThread每隔100ms运行一次MessageQueue.nativePollOnce - > WebViewCore.nativeSetScrollOffset,这导致重新绘制webview(在bakground中)(WebViewCore.nativeDrawContent).

这是一般的WebView问题还是我的应用程序中的问题？

我只是尝试将我的应用程序部署5次,并且每次都会永久挂起:

08:02 PM Starting deployment.
08:02 PM Checking if deployment succeeded.
08:02 PM Will check again in 1 seconds.
08:02 PM Checking if deployment succeeded.
08:02 PM Will check again in 2 seconds.
08:02 PM Checking if deployment succeeded.
08:02 PM Will check again in 4 seconds.
08:02 PM Checking if deployment succeeded.
08:02 PM Will check again in 8 seconds.
08:02 PM Checking if deployment succeeded.
08:02 PM Will check again in 16 seconds.
08:02 PM Checking if deployment …