Android 5.0（包含5.0以下版本）获取栈顶应用程序包名

/**
* 获取程序包名(本程序包名5.0版本上下都可获取)
*
* @return
*/
public String getTaskPackname() {
ActivityManager.RunningAppProcessInfo currentInfo = null;
Field field = null;
int START_TASK_TO_FRONT = 2;
String currentApp = "CurrentNULL";
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) {
try {
field = ActivityManager.RunningAppProcessInfo.class.getDeclaredField("processState");
} catch (Exception e) {
e.printStackTrace();
}
ActivityManager am = (ActivityManager) mContext.getSystemService(Context.ACTIVITY_SERVICE);
List<RunningAppProcessInfo> appList = am.getRunningAppProcesses();
for (ActivityManager.RunningAppProcessInfo app : appList) {
if (app.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND) {
Integer state = null;
try {
state = field.getInt(app);
} catch (Exception e) {
e.printStackTrace();
}
if (state != null && state == START_TASK_TO_FRONT) {
currentInfo = app;
break;
}
}
}
if (currentInfo != null) {
currentApp = currentInfo.processName;
}
} else {
ActivityManager am = (ActivityManager) mContext.getSystemService(Context.ACTIVITY_SERVICE);
List<ActivityManager.RunningAppProcessInfo> tasks = am.getRunningAppProcesses();
currentApp = tasks.get(0).processName;
}
Log.e("TAG", "Current App in foreground is: " + currentApp);
return currentApp;
}