将嵌套的ListBox中的选定项目与SelectionMode =“Multiple”和BindableSelection扩展 [英] Binding selected items in nested ListBox with SelectionMode="Multiple" and BindableSelection extension

问题描述

我正在开发具有MVVM模式的Windows Phone 8.1应用程序（我使用Prism作为框架）

I'm developing a Windows Phone 8.1 app with MVVM pattern (I'm using Prism as a framework)

目标是将所选项目很少有这样的列表：

The goal is to get the selected items in a few lists, like that:

< img src =https://i.stack.imgur.com/kD4JA.jpgalt =enter image description here>

我有以下XAML：

    <ListView 
    x:Name="abc"
    ItemsSource="{Binding Symbols}">
    <ListView.ItemTemplate>
        <DataTemplate>
            <StackPanel>
                <ListBox
                    SelectionMode="Multiple"
                    ItemsSource="{Binding List}"
Extensions:ListViewExtensions.BindableSelection="{Binding SelectedItems, ElementName=abc, Mode=TwoWay}">
                    ...

在ViewModel中：

and in the ViewModel:

    public List<SymbolsGroupViewModel> Symbols {
        get { return _symbols ?? (_symbols = _dataService.Symbols.GetGroupViewModels()); }
        set { _symbols = value; }
    }

其中class SymbolsGroupViewModel 看起来像：

where class SymbolsGroupViewModel looks like that:

public class SymbolsGroupViewModel : ViewModel
{
    private readonly INavigationService _navigationService;
    private readonly DataService _dataService;

    private ObservableCollection<Symbol> _selectedItems = new ObservableCollection<Symbol>();

    public SymbolsGroupViewModel(INavigationService navigationService, DataService dataService)
    {
        _navigationService = navigationService;
        _dataService = dataService;
    }

    public SymbolsGroupViewModel() { }

    public Symbol Header { get; set; }

    public List<Symbol> List { get; set; }

    public ObservableCollection<Symbol> SelectedItems
    {
        get { return _selectedItems; }
        set { SetProperty(ref _selectedItems, value); }
    }
}

应该使用 BntableSelection 从WinRT XAML Toolkit的扩展名，如下所示：
http://stackoverflow.com / a / 25430935/5194338

It is supposed to use the BindableSelection extension from WinRT XAML Toolkit, like here: http://stackoverflow.com/a/25430935/5194338

它适用于没有嵌套列表的我，但是当我将解决方案调整为嵌套列表时， SelectedItems 列表包含0个元素。

It works for me with NOT nested lists, however when I adapt the solution to nested list, the SelectedItems lists contain 0 elements.

有人知道是否可以在嵌套列表中使用此扩展名，如果是，我做错了什么？

感谢您的帮助。

推荐答案

我发现错误在哪里，所以我会离开答案，以防有人有类似的问题...

I've found where the mistake was so I'll leave the answer in case someone had similar problem...

在嵌套列表绑定应该写成如下：

In the nested list the binding should have been written as below:

Extensions:ListBoxExtensions.BindableSelection="{Binding SelectedItems, Mode=TwoWay}"

• 给予 ElementName 是一个坏主意


• 我以前没有注意到，那里是各种列表的单独扩展。在我的情况下，我应该使用 ListBoxExtensions 。


• Giving there ElementName was a bad idea
• I haven't noticed before, that there are separate extensions for each kind of list. In my case I should have used ListBoxExtensions.

希望这将有助于某人将来。

Hope this will help someone in the future.

这篇关于将嵌套的ListBox中的选定项目与SelectionMode =“Multiple”和BindableSelection扩展的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！