Android判断程序是否在前台运行

public Boolean isBackground(Context context)
{

ActivityManager activityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
List<RunningAppProcessInfo> appProcesses = activityManager.getRunningAppProcesses();
for (RunningAppProcessInfo appProcess : appProcesses)
{
if (appProcess.processName.equals(context.getPackageName()))
{
if (appProcess.importance == RunningAppProcessInfo.IMPORTANCE_BACKGROUND)
{
// Log.i(String.format("Background App:",appProcess.processName));
return false;
} else
{
// Log.i(String.format("Foreground App:",appProcess.processName));
return true;
}
}
}
return true;
}