监听应用是否切到后台

/**
 * 文件名：BaseActivity.java
 * 版本号：
 * 日期：2012-6-20
 * 创建人：
 * Copyright wadata 版权所有
 * 变更：
 */

packagecom.wadata.mobilefollowup.view.base;

importjava.util.List;
importandroid.app.Activity;
importandroid.app.ActivityManager;
importandroid.app.ActivityManager.RunningAppProcessInfo;
importandroid.content.Context;

/**
 * 名称：BaseActivity
 * 描述：
 * 创建人：
 * 日期：2012-6-20 下午5:53:35
 * 变更：
 */

publicclassBaseActivityextendsActivity {
      @Override
      protectedvoidonStop() {
              // TODO Auto-generated method stub
              super.onStop();

              if(!isAppOnForeground()) {
                      //app 进入后台

                      //全局变量isActive = false 记录当前已经进入后台
              }
      }

      @Override
      protectedvoidonResume() {
              // TODO Auto-generated method stub
              super.onResume();


              //if (!isActive) {
                      //app 从后台唤醒，进入前台

                      //isActive = true;
              //}
      }

      /**
        * 程序是否在前台运行
        *
        * @return
        */
      publicbooleanisAppOnForeground() {
              // 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<RunningAppProcessInfo> appProcesses = activityManager
                              .getRunningAppProcesses();
              if(appProcesses ==null)
                      returnfalse;

              for(RunningAppProcessInfo appProcess : appProcesses) {
                      // The name of the process that this object is associated with.
                      if(appProcess.processName.equals(packageName)
                                      && appProcess.importance == RunningAppProcessInfo.IMPORTANCE_FOREGROUND) {
                              returntrue;
                      }
              }

              returnfalse;
      }
}