前言:
应用场景:很多时候我们需要去监听用户有没有将APPs放置在后台,比如常用的银行类APP、音视频播放类APP,那么这些APP为什么要去监听应用程序在不在前台?
银行当然是为了安全,必须保证一些数据的传输一定是在前台,音视频播放APP呢,是为了更好的用户体验,用户按下home键切换到其他页面,期望是想让正在播放的电影暂停下来,而不是看不到视频页面而APP还在不停的播放,鉴于此种目的,我们需要做监听APP前后台应用。现在找到两种方法来实现:
一:BaseActivity基类+ActivityManager.RunningAppProcessInfo
首先,创建所有activity的基类,项目中所有Activity去继承BaseActivity,这样就可以统一管理,BaseActivity当然会有各种生命周期,onResume()和onStop()中去判断执行逻辑代码,也就是说进入一个Activity页面 它的onResume肯定会执行,home键退出应用程序肯定会走onStop,逻辑伪代码综上所述,下面来看代码
public class BaseActivity extends Activity {
public static boolean isActive; //全局变量
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_base);
}
@Override
protected void onResume() {
if (!isActive) {
//app 从后台唤醒,进入前台
isActive = true;
Log.i("ACTIVITY", "程序从后台唤醒");
}
super.onResume();
}
@Override
protected void onStart() {
super.onStart();
}
@Override
protected void onPause() {
super.onPause();
}
@Override
protected void onStop() {
if (!isAppOnForeground()) {
//app 进入后台
isActive = false;//记录当前已经进入后台
Log.i("ACTIVITY", "程序进入后台");
}
super.onStop();
}
@Override
protected void onDestroy() {
super.onDestroy();
}
/**
* APP是否处于前台唤醒状态
*
* @return
*/
public boolean isAppOnForeground() {
ActivityManager activityManager = (ActivityManager) getApplicationContext().getSystemService(Context.ACTIVITY_SERVICE);
String packageName = getApplicationContext().getPackageName();
List appProcesses = activityManager
.getRunningAppProcesses();
if (appProcesses == null)
return false;
for (ActivityManager.RunningAppProcessInfo appProcess : appProcesses) {
// The name of the process that this object is associated with.
if (appProcess.processName.equals(packageName)
&& appProcess.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND) {
return true;
}
}
return false;
}
}
二:Application中注册声明周期监听回调
首先,创建当前项目的Application去继承系统的Application,在Application中实现onCreate()方法,方法中注册reginsterActivitylifecycleCallBacks回调,来看代码实现
public class TheApplication extends Application {
private int mFinalCount;
@Override
public void onCreate() {
super.onCreate();
registerActivityLifecycleCallbacks(new ActivityLifecycleCallbacks() {
@Override
public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
}
@Override
public void onActivityStarted(Activity activity) {
mFinalCount++;
//如果mFinalCount ==1,说明是从后台到前台
Log.e("onActivityStarted", mFinalCount +"");
if (mFinalCount == 1){
//说明从后台回到了前台
}
}
@Override
public void onActivityResumed(Activity activity) {
}
@Override
public void onActivityPaused(Activity activity) {
}
@Override
public void onActivityStopped(Activity activity) {
mFinalCount--;
//如果mFinalCount ==0,说明是前台到后台
Log.i("onActivityStopped", mFinalCount +"");
if (mFinalCount == 0){
//说明从前台回到了后台
}
}
@Override
public void onActivitySaveInstanceState(Activity activity, Bundle outState) {
}
@Override
public void onActivityDestroyed(Activity activity) {
}
});
}
}
这样基本上实现了app前后台切换的动态监听。