Android Activity回收与操作超时处理

本文实例为大家分享了Android Activity回收与操作超时的处理，供大家参考，具体内容如下

1、Activity的回收

针对多个activity退出的处理

关键代码：

1）、新建活动管理类：

public class ActivityCollector {
  private static List activityList = new ArrayList();
  public static void addActivity(Activity activity){
    activityList.add(activity);
  }
  public static void removeActivity(Activity activity){
    activityList.remove(activity);
  }

  public static void finishAllButLast(){
    Activity activity = activityList.get(activityList.size()-1);
    removeActivity(activity);

    for (Activity activityItem: activityList){
      if (!activityItem.isFinishing()){
 activityItem.finish();
      }
    }

    activityList.clear();
    activityList.add(activity);
  }

  public static void finishAll(){
    for (Activity activity: activityList){
      if (!activity.isFinishing()){
 activity.finish();
      }
    }

    activityList.clear();
  }
}

2）、创建基类baseActivity，并使所有的activity继承自该基类 。在创建时，添加到活动管理器，销毁时，从活动管理器中移除。

public class baseActivity extends Activity {
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    ActivityCollector.addActivity(this);
  }

  @Override
  protected void onDestroy() {
    super.onDestroy();
    ActivityCollector.removeActivity(this);
  }
}

如果需要销毁所有activity，只需调用finishAll()即可

2、操作超时处理

原理：

1）、在activity的stop函数中，根据app进程importANCE_FOREGROUND判断app在前台或后台
2）、在activity的onResume函数中，做超时检查。

关键代码：

abstract public class TimeOutCheckActivity extends baseActivity {
  private boolean isLeave = false;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    pref = getSharedPreferences(Constant.CONFIG_NAME, Context.MODE_PRIVATE);
  }

  
  abstract protected String getTag();

  ......省略号......

  
  @Override
  protected void onResume() {
//    Log.i("Back",getTag() + "，onResume，是否在前台：" + isonForeground());
    super.onResume();
    if (isLeave) {
      isLeave = false;
      timeOutCheck();
    }
  }

  @Override 
  protected void onStop() {
    super.onStop();
    if (!isonForeground()){
      if (!isLeave && isOpenALP()) {
 isLeave = true;
 saveStartTime();
      }
    }
  }

  public void timeOutCheck() {
    long endtime = System.currentTimeMillis();
    if (endtime - getStartTime() >= Constant.TIMEOUT_ALP * 1000) {
      Util.toast(this, "超时了,请重新验证");
      String alp = pref.getString(Constant.ALP, null);
      if (alp == null || alp == "") {
      } else {
 Intent intent = new Intent(this, UnlockGesturePasswordActivity.class);
 intent.putExtra("pattern", alp);
 intent.putExtra("login",false); //手势验证，不进行登录验证
 intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
 // 打开新的Activity
 startActivityForResult(intent, Constant.REQ_COMPARE_PATTERN_TIMEOUT_CHECK);
      }
    }
  }

  public void saveStartTime() {
    pref.edit().putLong(Constant.START_TIME, System.currentTimeMillis()).commit();
  }

  public long getStartTime() {
    long startTime = 0;
    try {
      startTime = pref.getLong(Constant.START_TIME, 0);
    }catch (Exception e){
      startTime = 0;
    }
    return startTime;
  }

  
  public boolean isonForeground() {
    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) {
      if (appProcess.processName.equals(packageName)
   && appProcess.importance == ActivityManager.RunningAppProcessInfo.importANCE_FOREGROUND) { 
 return true;
      }
    }

    return false;
  }
}

补充说明：

可以根据importance的不同来判断前台或后台，RunningAppProcessInfo 里面的常量IMTANCE就是上面所说的前台后台，其实IMOPORTANCE是表示这个app进程的重要性，因为系统回收时候，会根据IMOPORTANCE来回收进程的。具体可以去看文档。

public static final int importANCE_BACKGROUND = 400//后台 
public static final int importANCE_EMPTY = 500//空进程 
public static final int importANCE_FOREGROUND = 100//在屏幕最前端、可获取到焦点 可理解为Activity生命周期的onResume(); 
public static final int importANCE_SERVICE = 300//在服务中 
public static final int importANCE_VISIBLE = 200//在屏幕前端、获取不到焦点可理解为Activity生命周期的onStart();