Question

我不确定我是以错误的方式接近这个，看不到解决方案，或者只是在wpf引擎中达到了限制。我有一个UserControl，其中有一个网格，我正在尝试在控件中的网格视图中设置DisplayMemberBinding来自调用它的控件：

UserControl：（为简洁而剪裁）

<UserControl x:Class="MyAssembly.UserControls.IncludedItems">
    <Grid>
        <ListView x:Name="lstViewItems" Grid.Row="0" ItemsSource="{Binding AffectedFiles, FallbackValue={x:Null}}">
            <ListView.View>
                <GridView>
                    <GridViewColumn Width="90">
                        <GridViewColumn.HeaderTemplate>
                            <DataTemplate>
                                <DockPanel>
                                    <CheckBox Margin="5,2" IsChecked="{Binding Path=DataContext.AllSelected, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type UserControl}}, FallbackValue=false}" />
                                    <TextBlock Text="Include?" />
                                </DockPanel>
                            </DataTemplate>
                        </GridViewColumn.HeaderTemplate>
                        <GridViewColumn.CellTemplate>
                            <DataTemplate>
                                <Grid Width="90">
                                    <CheckBox HorizontalAlignment="Center" IsChecked="{Binding ShouldInclude}" />
                                </Grid>
                            </DataTemplate>
                        </GridViewColumn.CellTemplate>
                    </GridViewColumn>
                    <GridViewColumn
                        x:Name="gvcDisplayPath"
                        Header="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=UserControl}, Path=ColumnHeader, FallbackValue=Path}" />
                </GridView>
            </ListView.View>
        </ListView>
    </Grid>
</UserControl>

所以在gvcDisplayPath我希望能够从调用控件设置DisplayMemberPath：

<Window x:localControls="clr-namespace:MyAssembly.UserControls">
    <Grid>
        ...
        <localControls:IncludedItems DataContext="{Binding FallbackValue={StaticResource vmDesignModel}}" DisplayMemberPath="Catalog" ColumnHeader="Site" />
        ...
    </Grid>
</Window>

我确实尝试在ctr和OnInitialised方法中设置代码隐藏，基于依赖属性，但是没有用（因为dp没有设置）到那时它的价值）。

由于

Answer 1

我的最终解决方案是挂钩用户控件上的DependencyProperty注册中的PropertyChangedCallback，并从那里更新绑定（为简洁而剪切）：

public partial class IncludedItems : UserControl {

    public static readonly DependencyProperty DisplayMemberPathProperty = DependencyProperty.Register("DisplayMemberPath", typeof(string), typeof(TargetedItemView), new UIPropertyMetadata("Item", DisplayMemberPathPropertyChanged));

    private static void DisplayMemberPathPropertyChanged(object sender, DependencyPropertyChangedEventArgs e) {
        IncludedItems view = sender as IncludedItems;
        if (null == view)
            return;

        view.gvcDisplayPath.DisplayMemberBinding = new Binding(view.DisplayMemberPath) { TargetNullValue = String.Empty, FallbackValue = String.Empty };
    }

}

将绑定表达式传递给usercontrol

1 个答案: