是否可以显示列表框的第一个元素，而不是为 xaml 创建数据模板

>以下绑定位于 IEnumerable 调用的活动上。问题是，在我的xaml...我只想输出数组中的第一个元素。你能按照这些思路做点什么吗：

<Run Text="{Binding activity[0].created_by.name}"></Run>

还是必须为活动 IEnumerable 数组链接另一个数据模板？

这是 ActivityStream 类的属性（我现在注意到它是一个列表。嗯。

...
    [DataMember]
    public List<object> activity { get; set; }
...

这是我做的地方 财产改变了 yada yada 的东西

    public IEnumerable<JamesStream> activityStream;
...
    private async void LoadActivityStreamSection()
    {
        activityStreamRepository = new JamesStreamRepository();
        var tempActivityStream = await activityStreamRepository.GetAllBySpaceId(space.space_id);
        activityStream = tempActivityStream;
        ActivityStream = null;
        //The Activitiy Stream has a property which is of type List<object> called activity
        // In my xaml I just want to be outputting the 1st entry of the List<object> property .created_by_name
    }
    public event PropertyChangedEventHandler PropertyChanged;
    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChangedEventHandler tempEvent = PropertyChanged;
        if (tempEvent != null)
        {
            // property changed
            tempEvent(this, new PropertyChangedEventArgs(propertyName));
        }
    }
    public IEnumerable<JamesStream> ActivityStream
    {
        get
        {
            return activityStream;
        }
        set
        {
            if (activityStream != value)
            {
                OnPropertyChanged();
            }
        }
    }