将DatePicker的日期绑定到ConverterParameter

Question

我正在尝试使用转换器类基于DatePicker中的Date在ComboBox中标记Names.

我目前的问题是我不知道如何将DatePicker的日期绑定到"ConverterParameter".有什么建议？

(我的代码中可能有更多错误,但此时我已经陷入困境)

<Page.Resources>  
    <Style TargetType="ComboBoxItem" x:Key="combostyle">

        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="ComboBoxItem">
                    <ControlTemplate.Resources>
                        <src:ColorFromMagazijnierIdConverter x:Key="conv" />
                    </ControlTemplate.Resources>

                    <Grid ToolTip="{Binding Converter={StaticResource conv}, ConverterParameter={ BIND THIS TO THE DATEPICKER DATE }, Mode=OneWay}">
                        <Rectangle x:Name="MarkedItemBackground" IsHitTestVisible="False" Fill="#80FF0000" />
                        <!--...-->
                    </Grid>
                    <ControlTemplate.Triggers>
                        <DataTrigger Binding="{Binding Converter={StaticResource conv}}"
                                         Value="{x:Null}">
                            <Setter TargetName="MarkedItemBackground" 
                                        Property="Visibility" Value="Hidden" />
                        </DataTrigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</Page.Resources>
<Grid Margin="10,10,10,0" Name="rootGrid">
    <ComboBox Name="collectMagazijnierComboBox"
              DisplayMemberPath="User.Name"
              ItemContainerStyle="{DynamicResource ResourceKey=combostyle}"/>
    <DatePicker Name="collectDatePicker" />
</Grid>

Answer 1

ConverterParameter属性不能是绑定的目标.只有DependencyObject的DependencyProperty才能成为绑定的目标.

您需要使用MultiBinding:

<Grid>
    <Grid.ToolTip>
        <MultiBinding Converter="{StaticResource conv}" Mode="OneWay">
            <Binding /> <!-- this mimics your current binding to the datacontext itself -->
            <Binding ElementName="collectDatePicker" Path="SelectedDate" />
        </MultiBinding>
    </Grid.ToolTip>

    <Rectangle x:Name="MarkedItemBackground" IsHitTestVisible="False" Fill="#80FF0000" />

    <!--...-->

</Grid>

然后,您需要重写ColorFromMagazijnierIdConverter转换器来实现IMultiValueConverter接口,您可以在其中访问这两个值.

虽然,我不是100%确定你是否可以在样式资源中引用ElementName的collectDatePicker.但你肯定可以玩它!