如何在不使用分页的情况下实现延迟加载的Silverlight数据网格

为了展示它的易用性,以下是样本中的一些片段.首先,这是你如何使用VirtualCollection,这是一个坐标获取数据的类：

public class Mainviewmodel : viewmodel
{
    private Netflixtitlessource _source;

    public VirtualCollection<title> Items { get; private set; }

    public Mainviewmodel()
    {
        _source = new Netflixtitlessource();
        Items = new VirtualCollection<title>(_source,pageSize: 20,cachedPages: 5);
    }

    protected override void OnViewLoaded()
    {
        Items.refresh();
    }
}

在XAML中,您只需将Items属性绑定到ListBox或DataGrid的Itemssource属性

对于每个数据源,您必须实现VirtualCollectionsource.以下是NetflixTitlesSource的两个关键方法：

public class Netflixtitlessource : VirtualCollectionsource<title>
{
    protected override Task<int> GetCount()
    {
        return GetQueryResults(0,1,null)
            .ConTinueWith(t => (int)t.Result.@R_589_10586@lCount,TaskConTinuationOptions.ExecuteSynchronously);
    }

    protected override Task<IList<title>> GetPageAsyncOverride(int start,int pageSize,IList<SortDescription> sortDescriptions)
    {
        return GetQueryResults(start,pageSize,sortDescriptions)
            .ConTinueWith(t => (IList<title>)((IEnumerable<title>)t.Result).ToList(),TaskConTinuationOptions.ExecuteSynchronously);
    }

    private Task<QueryOperationResponse<title>> GetQueryResults(int start,IList<SortDescription> sortDescriptions)
    {
        // code to query the Netflix OData API
    }
}