判断Android程序是否在前台运行的两种方法

@override 
protected void onstop() { 
  if (!isapponforeground()) { 
    debug.i("dwy", "enter background"); 
    misbackground = true; 
  } else { 
    debug.i("dwy", "foreground"); 
    misbackground = false; 
  } 

judge is app in background when onstop() get called.

public boolean isapponforeground() { 
    // returns a list of application processes that are running on the 
    // device 
 
    activitymanager activitymanager = (activitymanager) getapplicationcontext().getsystemservice(context.activity_service); 
    string packagename = getapplicationcontext().getpackagename(); 
 
    list<activitymanager.runningappprocessinfo> 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; 
  } 

方法二：

/** 
  * 需要权限:android.permission.get_tasks 
  * 
  * @param context 
  * @return 
  */ 
  public boolean isapplicationbroughttobackground(context context) { 
    activitymanager am = (activitymanager) context 
            .getsystemservice(context.activity_service); 
    list<runningtaskinfo> tasks = am.getrunningtasks(1); 
    if (tasks != null && !tasks.isempty()) { 
      componentname topactivity = tasks.get(0).topactivity; 
      debug.i(tag, "topactivity:" + topactivity.flattentostring()); 
      debug.f(tag, "topactivity:" + topactivity.flattentostring()); 
      if (!topactivity.getpackagename().equals(context.getpackagename())) { 
        return true; 
      } 
    } 
    return false; 
  }