Question

通常，我们不能将多个控件绑定到一个ObservableCollection

在以下情况下可以这样做吗？

一次只能看到一个部分

在这种情况下，同一集合两次出现参考错误

它实际上如何在内部工作？它不应该包含不可见的代码吗？

<Grid Visibility="{Binding B1Visible, Converter={StaticResource BooleanToVisibilityConverter}}">
    <ItemsControl ItemsSource="{Binding Elements, UpdateSourceTrigger=PropertyChanged}">
        <ItemsControl.ItemsPanel>
            <ItemsPanelTemplate>
                <Grid />
            </ItemsPanelTemplate>
        </ItemsControl.ItemsPanel>
    </ItemsControl>
    <!--Another code for B1-->
</Grid>

<Grid Visibility="{Binding B2Visible, Converter={StaticResource BooleanToVisibilityConverter}}">
    <ItemsControl ItemsSource="{Binding Elements, UpdateSourceTrigger=PropertyChanged}">
        <ItemsControl.ItemsPanel>
            <ItemsPanelTemplate>
                <Grid />
            </ItemsPanelTemplate>
        </ItemsControl.ItemsPanel>
    </ItemsControl>
    <!--Another code for B2 -->
</Grid>

Answer 1

我不知道什么是元素，也不知道您要使用itemscontrol的itempanel的网格到哪里去。

但是。

您可以多次绑定到同一可观察的集合。

在下面的代码中，两个可见性属性为Boolean，转换器将true转换为Visibility.Visible，将false转换为Visibility.Collapsed。

public class MainWindowViewModel : BaseViewModel
{
    private ObservableCollection<Person> people = new ObservableCollection<Person>();

    public ObservableCollection<Person> People
    {
        get { return people; }
        set { people = value;  RaisePropertyChanged();}
    }
    private bool b1Visible = true;

    public bool B1Visible
    {
        get { return b1Visible; }
        set { b1Visible = value; RaisePropertyChanged(); }
    }
    private bool b2Visible = true;

    public bool B2Visible
    {
        get { return b2Visible; }
        set { b2Visible = value; RaisePropertyChanged(); }
    }
    public MainWindowViewModel()
    {
        People.Add(new Person { FirstName = "Chesney", LastName = "Brown" });
        People.Add(new Person { FirstName = "Gary", LastName = "Windass" });
        People.Add(new Person { FirstName = "Liz", LastName = "McDonald" });
        People.Add(new Person { FirstName = "Carla", LastName = "Connor" });
    }
}

我的标记：

<Window.Resources>
    <BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter"/>
</Window.Resources>
<Window.DataContext>
    <local:MainWindowViewModel/>
</Window.DataContext>
<StackPanel>
    <Grid Visibility="{Binding B1Visible, Converter={StaticResource BooleanToVisibilityConverter}}">
        <ItemsControl ItemsSource="{Binding People}">
            <ItemsControl.ItemTemplate>
                <DataTemplate>
                    <TextBlock Text="{Binding LastName}" />
                </DataTemplate>
            </ItemsControl.ItemTemplate>
        </ItemsControl>
        <!--Another code for B1-->
    </Grid>
    <Grid Visibility="{Binding B2Visible, Converter={StaticResource BooleanToVisibilityConverter}}">
        <ItemsControl ItemsSource="{Binding People}">
            <ItemsControl.ItemTemplate>
                <DataTemplate>
                    <TextBlock Text="{Binding LastName}" />
                </DataTemplate>
            </ItemsControl.ItemTemplate>
        </ItemsControl>
    </Grid>
</StackPanel>

两个项目控件都是可见的，因此我看到了两次名称列表。

将多个ItemsControl绑定到一个包含可见性的ObservableCollection

1 个答案: