ItemsSource绑定不更新值

Question

我需要列出项目.我将用户集合绑定到列表框.一切都很好,但列表框中的项目不会实时更新.它们根本没有更新.因此,当我从列表中删除任何用户时,即使其源已正确更改,列表框也不会更新.

Source位于路径DataViewModel.Instance.AllUsers的数据视图模型中; 每当我向此列表添加新项目或删除一项时,布局都不会更新.其他绑定工作得很好.我试图更新列表框布局,提出源更新事件,添加/删除项目的其他方式,但没有任何工作.

我试图调试绑定,但我有太多的绑定来找到错误.

提前感谢任何有用的建议.

列表框:

<ListBox x:Name="ListboxUsers" ItemsSource="{Binding Path=AllUsers, Mode=OneWay}" Grid.Column="1" Margin="0" Grid.Row="5" Background="DimGray" BorderThickness="0" Visibility="Hidden" SelectionChanged="ListboxUsers_SelectionChanged"/>

代码隐藏:

CatalogueGrid.DataContext = DataViewModel.Instance;    //whole view model added as datacontext

DataViewModel类:

public class DataViewModel : INotifyPropertyChanged
{
    private static DataViewModel _dataViewModel;

    private Collection<UserModel> allUsers;
    public Collection<UserModel> AllUsers
    {
        get
        {
            return allUsers;
        }
        set
        {
            allUsers = value;
            NotifyPropertyChanged("AllUsers");
        }
    }


    private DataViewModel()
    {
        AllUsers = new Collection<UserModel>();
    }    

    public event PropertyChangedEventHandler PropertyChanged;
    private void NotifyPropertyChanged(string info)
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (handler != null)
        {
            handler(this, new PropertyChangedEventArgs(info));
        }
    }
    .
    .
    .

}

Answer 1

用ObservableColLection,而是如果Collection至极实现的INotifyCollectionChanged接口:

private ObservableCollection<UserModel> allUsers;
public ObservableCollection<UserModel> AllUsers
{
    get
    {
        return allUsers;
    }
    set
    {
        allUsers = value;
        NotifyPropertyChanged("AllUsers");
    }
}

Answer 2

对于要传播到UI的集合的更改,集合类需要实现INotifyCollectionChanged.

一个非常有用的类已经实现了这个ObservableCollection<T>(MSDN).用它代替Collection<T>.