Question

所以我有一个基本的视图模型，其功能如下：

// The ICollectionVIew is what my ListBox binds to.
public ICollectionView UserView { get; set; }

// <signup> is a model that's populated from a database representing a signup table
private ObservableCollection<signup> _signup;

    public ObservableCollection<signup> Signup
    {
        get
        {

            return _signup;
        }
        set
        {
            if (_signup != value)
            {
                value = _signup;
            }

            OnPropertyChanged("Signup");
        }
    }

    // This is the constructor for the ViewModel
    public registrationVM()
    {
        // entity context Fills up the Model 
        context.signups.Load();
        // The below code fills up the ObservableCollection
        var query = context.signups;
        _signup = new ObservableCollection<signup>(query);

        // And the below code fills up the ICollectionView using the ObservableCollection
        UserView = CollectionViewSource.GetDefaultView(_signup);

    }

所以现在不是绑定到ObservableCollection，而是绑定到ICollection。

<ListBox ItemsSource="{Binding UserView}" DisplayMemberPath="firstName" SelectedItem="{Binding SelectedUser}"/>

这在加载我的信息方面非常有效。但现在出现了导航问题。我将我的按钮命令绑定到ViewModel，

<Button x:Name="next" Command="{Binding Next}"/>

并执行它的方法：

    private object Next_CommandExecute(object param)
    {
        // 'UserView' Is the ICollectionView I declared earlier
        return UserView.MoveCurrentToNext();
    }

问题是按钮的功能没有做任何事情。 “前一个”按钮也是如此。屏幕上选择的记录没有改变所以我猜我有些错误。究竟是什么我一直未能弄明白。有谁看到我哪里出错？

Answer 1

正如my comment中所述，您需要在IsSynchronizedWithCurrentItem = true上设置ListBox

ListBox ItemsSource="{Binding UserView}" 
        DisplayMemberPath="firstName"
        IsSynchronizedWithCurrentItem = true 
        SelectedItem="{Binding SelectedUser}"/>

如何浏览ICollectionView？

1 个答案: