如何制作分页ListView?

时间:2012-08-07 16:27:40

标签: c# mvvm microsoft-metro

我有很长的项目列表,我需要在ListView中显示它们。然后我需要使用计时器自动旋转页面。怎么办?

1 个答案:

答案 0 :(得分:0)

(Windows 8风格的UI / Metro应用)

在您的视图中:将{Binding PagedItems}添加到ListView的ItemSource属性中。

在ViewModel中:

public class ViewModel : INotifyPropertyChanged {

    public ObservableCollection<Item> PagedItems {get;set;}
    private DispatcherTimer _timer;

    private ObservableCollection<Item> _itemsToPage;
    private int _itemsPerPage;
    private int _currentPage;

    public ViewModel() {
        _itemsToPage = new ObservableCollection<Item>(); // replace this with whatever your items are

        _timer = new DispatcherTimer {Interval = new TimeSpan(0,0,0,10)};
        _timer.Tick += NextPage;
        _timer.Start();
    }

    private void NextPage(object sender, object e) {
        if (_itemsToPage < _itemsPerPage) return;

        if (_currentPage * _itemsPerPage >= _itemsToPage) _currentPage = 1;
        else _currentPage++;

        // the key line
        PagedItems = new ObservableCollection<Item>(
            _itemsToPage.Skip((_currentPage-1) * _itemsPerPage)
                .Take(_itemsPerPage));

        OnPropertyChanged("PagedItems") // you need to implement INotifyPropertyChanged
    }
}

基本思路:每x秒根据您要分页的列表中的项目子集创建新列表。您会注意到(_currentPage-1) * _itemsPerPage是每页上第一个项目的元素编号。