Android开发中，有时候需要判断App是否在前台运行。

代码实现如下：

private boolean isRunningForeground (Context context)
{
    ActivityManager am = (ActivityManager)context.getSystemService(Context.ACTIVITY_SERVICE);
    ComponentName cn = am.getRunningTasks(1).get(0).topActivity;
    String currentPackageName = cn.getPackageName();
    if(!TextUtils.isEmpty(currentPackageName) && currentPackageName.equals(getPackageName()))
    {
        return true ;
    }
 
    return false ;
}

1. protected static boolean isTopActivity(Activity activity){
           String packageName = "xxxxx";
           ActivityManager activityManager = (ActivityManager) activity.getSystemService(Context.ACTIVITY_SERVICE);
           List<RunningTaskInfo>  tasksInfo = activityManager.getRunningTasks(1);  
           if(tasksInfo.size() > 0){  
               System.out.println("---------------包名-----------"+tasksInfo.get(0).topActivity.getPackageName());
               //应用程序位于堆栈的顶层  
               if(packageName.equals(tasksInfo.get(0).topActivity.getPackageName())){  
                   return true;  
               }  
           }  
           return false;
       }
2. 需要添加android.permission.GET_TASKS权限