Android 打开xx应用，点击home键，出现黑屏

问题描述

测试同学在测试过程中，打开了xx应用，然后点击home键，发生黑屏现象。

解决方案

从视频现象来看，桌面是处于黑屏的，但是statusBar以及dock栏是可以正常现实的，其实这种问题一般都是属于应用问题了。

下面我们继续从log解读：

启动com.xx.xx时间17:54:32，从log看，com.xx.xx这个应用一直处于前台，也就是说按home键之后，xx应用并没有回退到后台（以下log关于此应用信息全部用xx代替）：

12-21 17:54:32.975  1539  2049 I ActivityTaskManager: START u10 {act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10000000 pkg=com.xx.xx cmp=com.xx.xx/.xx(has extras)} from uid 1010018

12-21 17:54:32.979  1539  2049 I wm_set_resumed_activity: [10,com.xx.xx/.xx,bringingFoundTaskToFront]

12-21 17:54:32.979  1539  2049 I WindowManager: onActivityStackWindowModeChange toFont=true,launchedFromPackage=com.xx.xx,packageName=com.xx.xx

12-21 17:54:32.979  1539  2049 I wm_new_intent: [10,141496873,1001707,com.xx.xx/.xx,android.intent.action.MAIN,NULL,NULL,270548992]

12-21 17:54:32.985  1539  2077 I wm_resume_activity: [10,141496873,1001707,com.xx.xx/.xx]

12-21 17:54:32.986  4838  4838 I wm_on_restart_called: [141496873,com.xx.xx,performRestartActivity]

12-21 17:54:32.986  4838  4838 I wm_on_start_called: [141496873,com.xx.xx,handleStartActivity]

12-21 17:54:32.988  4838  4838 I wm_on_resume_called: [141496873,com.xx.xx,RESUME_ACTIVITY]

12-21 17:54:33.024  4838  4838 I wm_on_top_resumed_gained_called: [141496873,com.xx.xx,topStateChangedWhenResumed]

12-21 17:54:33.024  4838  4838 I wm_on_top_resumed_lost_called: [141496873,com.xx.xx,topStateChangedWhenResumed]

黑屏原因应该是surface未同步更新导致，图形渲染出现问题，这一步的流程是处于ViewRootImpl.java跟

SurfaceSyncer之间，如果流程正常在提交给wms处理，surface未同步更新也就导致对应的图形没有绘制出来。并且从下面log可以看出刚好问题发生的进程就是com.xx.xx，而且黑屏现象是statusBar以及dock栏可见。

12-21 17:54:33.006  4838 22487 E OpenGLRenderer: Unable to match the desired swap behavior.
12-21 17:54:33.007  2101 19425 I xx  : onForegroundActivitiesChanged uid 1010048 pid 4838 fg true
12-21 17:54:33.008  4838  4838 E SurfaceSyncer: Failed to find sync for id=0
12-21 17:54:33.008  4838  4838 E SurfaceSyncer: Failed to find sync for id=1
12-21 17:54:33.008  4838  4838 E SurfaceSyncer: Failed to find sync for id=2
12-21 17:54:33.008  4838  4838 E SurfaceSyncer: Failed to find sync for id=3

Android 打开xx应用，点击home键，出现黑屏