Question

我有一个public class User { private final SetProperty<Certificate> certificates = new SimpleSetProperty<>(FXCollections.observableSet()); public final ObservableSet<Certificate> getCertificates() { return certificatesProperty().get(); } public final void setCertificate(ObservableSet<Certificate> certificates) { certificatesProperty().set(certificates); } public SetProperty<Certificate> certificatesProperty() { return certificates ; } // other properties.... }被绑定到ViewModel中定义的ComboBox。我还有一个List<String>，其ItemSource取决于ListBox中的SelectedValue。

在ViewModel中，我有以下属性：

ComboBox
List<String> ComboBoxSource（string SelectedValue所选值）
ComboBox

现在，当ObservableCollection<String> ListBoxSource ComboBox更改时，我在ViewModel（selectedvalue）中明确设置SelectedVAlue属性，这会引发DataContext事件在PropertyChange上，以便更新ListBoxSource。

我的问题是如何在没有在ViewModel中明确设置ListBox的情况下执行此操作，即我可以将SelectedVAlue绑定到我的ComboBox.SelectedVAlue属性吗？

这是我的XAML：

SelectedVAlue

以下是Code Behind：

 <ComboBox Grid.Column="0" Grid.Row="0" x:Name="ComboBoxVersions"  SelectedIndex="0" Margin="10" SelectionChanged="ComboBoxVersions_OnSelectionChanged" ItemsSource="{Binding EnvironmentVersions}">
        <ComboBox.ItemTemplate>

            <DataTemplate>
                <StackPanel Orientation="Horizontal">
                    <TextBlock Text="Version " />
                    <TextBlock Text="{Binding}" />
                </StackPanel>
            </DataTemplate>
        </ComboBox.ItemTemplate>
    </ComboBox>


    <ListBox x:Name="ListBoxEnvironments" Grid.Column="0" Grid.Row="1" Height="300" Grid.ColumnSpan="2" HorizontalAlignment="Stretch" Margin="10" SelectionMode="Multiple" ItemsSource="{Binding Environments}">
        <ListBox.ItemsPanel>
            <ItemsPanelTemplate>
                <WrapPanel Orientation="Horizontal" HorizontalAlignment="Left" Width="800" >
                </WrapPanel>
            </ItemsPanelTemplate>
        </ListBox.ItemsPanel>
        <ListBox.ItemTemplate>
            <DataTemplate>
                <CheckBox x:Name="CheckBoxEnvironment" Content="{Binding}" IsChecked="{Binding RelativeSource={RelativeSource AncestorType={x:Type ListBoxItem}}, Path=IsSelected}" Margin="5">
                </CheckBox>
            </DataTemplate>
        </ListBox.ItemTemplate>
    </ListBox>

Answer 1

使用SelectedItem代替SelectedValue，因为它更适合绑定，只需创建一个SelectedVersion属性，将此属性绑定到combobox's SelectedItem，无论何时更改SelectedItem，都要在该属性的setter中更新ListBox itemSource。

INotifyPropertyChanged界面是必要的，让ListBox知道他们的来源已被更改

 private List<String> _environmentVersions;   
    public List<String> EnvironmentVersions
    {
        get
        {
            return _environmentVersions;
        }

        set
        {
            if (_environmentVersions == value)
            {
                return;
            }

            _environmentVersions = value;
            OnPropertyChanged();
        }
    }

    private ObservableCollection<String> _environments ;
    public ObservableCollection<String> Environments
    {
        get
        {
            return _environments;
        }

        set
        {
            if (_environments == value)
            {
                return;
            }

            _environments = value;
            OnPropertyChanged();
        }
    }

    private String _selectedVersion  ;
    public String SelectedVersion
    {
        get
        {
            return _selectedVersion;
        }

        set
        {
            if (_selectedVersion == value)
            {
                return;
            }

            _selectedVersion = value;
            //update your listBox itemSource 
            // ...
        }
    }

并在Xaml中：

<ComboBox Grid.Column="0" Grid.Row="0" x:Name="ComboBoxVersions"  SelectedIndex="0" Margin="10" SelectedItem="{Binding SelectedVersion}" ItemsSource="{Binding EnvironmentVersions}">
        <ComboBox.ItemTemplate>

            <DataTemplate>
                <StackPanel Orientation="Horizontal">
                    <TextBlock Text="Version " />
                    <TextBlock Text="{Binding}" />
                </StackPanel>
            </DataTemplate>
        </ComboBox.ItemTemplate>
    </ComboBox>

将ListBos ItemSource绑定到Combobox的selectedVAlue

1 个答案: