当遇到
E/AndroidRuntime(27033): android.view.WindowManager$BadTokenException: Unable to add window android.view.ViewRoot$W@40545a28 -- permission denied for this window type
类似错误时,可以尝试加上下面的权限
<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>
<uses-permission android:name="android.permission.SYSTEM_OVERLAY_WINDOW" />