1.问题 进入百度地图，开启导航，按home键回到桌面，此时在桌面出现一个百度地图的悬浮窗，点击小窗口进入百度地图；进入到百度地图主界面用时较长。
2.log及分析 按home键回到桌面，在桌面出现一个百度地图的悬浮窗：表示APP在后台运行； 按Home键回到桌面，在桌面点击百度地图图标进入，不会延时启动； //点击悬浮窗 10-22 09:01:10.040 6357 6357 I View : performClick --this:android.widget.LinearLayout{403ca7b VFE...C.. ...P..I. 0,0-392,104}--mContext:com.baidu.baidumaps.MapsActivity@69b06dc--packageName:com.baidu.BaiduMap--getCall:android.view.View.performClickInternal:7249 android.view.View.access$3600:808 android.view.View$PerformClick.run:27932 android.os.Handler.handleCallback:883 android.os.Handler.dispatchMessage:100 android.os.Looper.loop:221 android.app.ActivityThread.main:7552 java.lang.reflect.Method.invoke:-2 com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run:492 com.android.internal.os.ZygoteInit.main:935 //走到ActivityStarter中的startActivity(在这个方法中会调用checkAppSwitchAllowedLocked) 10-22 09:01:10.042 820 2866 I ActivityTaskManager: START u0 {flg=0x10200000 pkg=com.baidu.BaiduMap cmp=com.baidu.BaiduMap/com.baidu.baidumaps.MapsActivity} from uid 10144 of 6357 //请求被拒 10-22 09:01:10.047 820 2866 W ActivityTaskManager: Activity start request from 10144 stopped Activity start request from 10144 stopped是在ActivityTaskManagerService的checkAppSwitchAllowedLocked方法中输出：
boolean checkAppSwitchAllowedLocked(int sourcePid, int sourceUid, int callingPid, int callingUid, String name) { if (mAppSwitchesAllowedTime < SystemClock.uptimeMillis()) { return true; } if (getRecentTasks().isCallerRecents(sourceUid)) { return true; } int perm = checkComponentPermission(STOP_APP_SWITCHES, sourcePid, sourceUid, -1, true); if (perm == PackageManager.PERMISSION_GRANTED) { return true; } if (checkAllowAppSwitchUid(sourceUid)) { return true; } // If the actual IPC caller is different from the logical source, then // also see if they are allowed to control app switches. if (callingUid != -1 && callingUid != sourceUid) { perm = checkComponentPermission(STOP_APP_SWITCHES, callingPid, callingUid, -1, true); if (perm == PackageManager.PERMISSION_GRANTED) { return true; } if (checkAllowAppSwitchUid(callingUid)) { return true; } } Slog.w(TAG, name + " request from " + sourceUid + " stopped"); return false; }checkAppSwitchAllowedLocked是在ActivityStarter的startActivity中被调用：
// If we are starting an activity that is not from the same uid as the currently resumed // one, check whether app switches are allowed. if (voiceSession == null && (stack.getResumedActivity() == null || stack.getResumedActivity().info.applicationInfo.uid != realCallingUid)) { if (!mService.checkAppSwitchAllowedLocked(callingPid, callingUid, realCallingPid, realCallingUid, "Activity start")) { if (!(restrictedBgActivity && handleBackgroundActivityAbort(r))) { mController.addPendingActivityLaunch(new PendingActivityLaunch(r, sourceRecord, startFlags, stack, callerApp)); } ActivityOptions.abort(checkedOptions); return ActivityManager.START_SWITCHES_CANCELED; } }当通过home键将当前activity置于后台时，任何在后台startActivity的操作都将会延迟5秒，除非该应用获取了"android.permission.STOP_APP_SWITCHES"权限。 <!-- 按了home键再点击悬浮窗startactivity不用等5s的权限,系统层 --> <uses-permission android:name="android.permission.STOP_APP_SWITCHES" />
3.解决方式 (1)增加android.permission.STOP_APP_SWITCHES权限 <uses-permission android:name="android.permission.STOP_APP_SWITCHES" /> (2)使用以下方式启动Activity Intent intent = new Intent(this, xxx.class); intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); PendingIntent pi = PendingIntent.getActivity(context, 0, intent, 0); pi.send();
