将依赖项属性绑定到另一个XAML中

Question

I have created a dependency property in one of the usercontrols but need some way to bind it into another XAML(another usercontrol).Here is the C# code

DateRangeSelectorControl.cs

public static readonly DependencyProperty TodayDateProperty =
    DependencyProperty.Register("TodayDate",
    typeof(DateTime),
    typeof(DateRangeSelectorControl),
    new PropertyMetadata(null, TodayDateChanged));

I have another XAML(ActivityListMenuControlView.xaml) where i need to bind this property(TodayDateProperty) so that it can be exposed and it's callback called. Here is the XAML code:

<DateRangeSelector:DateRangeSelectorControl x:Name="DateRangeSelector"
                                            Grid.Column="1"
                                            Margin="10 0 0 0"
                                            HorizontalAlignment="Left"
                                            VerticalAlignment="Center"
                                            AutomationProperties.AutomationId="AID_TaskListDateRangeSelector"
                                            DateRangeUpdatedCmd="{Binding Path=DateRangeSelectionUpdatedCommand}"
                                            FontSize="{StaticResource TaskListMenuFontSize}"
                                            RangeOptions="{Binding Path=DateRangeSelectionOptions,
                                                                   Mode=OneTime}"
                                            SelectedDateRange="{Binding Path=SelectedRange,
                                                                        Mode=TwoWay}"
                                            Visibility="{Binding Path=ShowFilterOptions,
                                                                 Converter={StaticResource boolToVisibility}}" />

Is there any way?

UPDATE: As per the suggestion from OR Mapper, i have made the following change into this XAML(ActivityListMenuControlView.xaml):

  <DateRangeSelector:DateRangeSelectorControl x:Name="DateRangeSelector" Grid.Column="1" Margin="10 0 0 0" HorizontalAlignment="Left" VerticalAlignment="Center" AutomationProperties.AutomationId="AID_TaskListDateRangeSelector" DateRangeUpdatedCmd="{Binding Path=DateRangeSelectionUpdatedCommand}" FontSize="{StaticResource TaskListMenuFontSize}" RangeOptions="{Binding Path=DateRangeSelectionOptions, Mode=OneTime}" SelectedDateRange="{Binding Path=SelectedRange, Mode=TwoWay}" Visibility="{Binding Path=ShowFilterOptions, Converter={StaticResource boolToVisibility}}" TodayDateProperty="{Binding TodayDate, ElementName=DateRangeSelector}" 

Still i get an error : Property or event expected. Upon compilation i get the following errors:

Error 2 The property 'TodayDateProperty' was not found in type 'DateRangeSelectorControl'. Error 4 Default value type does not match type of property 'TodayDate'.

Any idea?

UPDATE: As suggested by Sheridan, i changed the XAML to something like:

  <DateRangeSelector:DateRangeSelectorControl x:Name="DateRangeSelector" Grid.Column="1" Margin="10 0 0 0" HorizontalAlignment="Left" VerticalAlignment="Center" AutomationProperties.AutomationId="AID_TaskListDateRangeSelector" DateRangeUpdatedCmd="{Binding Path=DateRangeSelectionUpdatedCommand}" FontSize="{StaticResource TaskListMenuFontSize}" RangeOptions="{Binding Path=DateRangeSelectionOptions, Mode=OneTime}" SelectedDateRange="{Binding Path=SelectedRange, Mode=TwoWay}" Visibility="{Binding Path=ShowFilterOptions, Converter={StaticResource boolToVisibility}}" TodayDate="{Binding TodayDate, ElementName=DateRangeSelector}"/> 

Wrapper property "TodayDate" is defined in DateRangeSelector as below:

DateRangeSelector.cs

  public DateTime TodayDate { get { return (DateTime)GetValue(TodayDateProperty); } set { SetValue(TodayDateProperty, value); } } 

And in the viewmodel(ActivityListMenuControlViewModel.cs) i created another "TodayDate"(as specified in the binding) as belowL

  public DateTime TodayDate { get; set; } 

On compilation i get the below errors:

Error 2 The property 'TodayDate' was not found in type 'DateRangeSelectorControl'. Error 12 Default value type does not match type of property 'TodayDate'.

Any help?

Answer 1

假设该属性属于一个名为SomeClass的类，该类的一个实例在ActivityListMenuControlView.xaml声明，并且称为SomeProperty ，并且假设您显示的Xaml代码段是ActivityListMenuControlView.xaml的一部分，则可以像这样简单地绑定它：

<SomeClass SomeProperty="{Binding TodayDate, ElementName=DateRangeSelector}"/>

Answer 2

It seems to me as though your error is telling you what the problem is:

The property 'TodayDateProperty' was not found in type 'DateRangeSelectorControl' . Error 4 Default value type does not match type of property 'TodayDate'.

This is because you did not register a DependencyProperty named TodayDateProperty in your control. So instead, try using the name of the DependencyProperty that you did register - TodayDate :

<DateRangeSelector:DateRangeSelectorControl x:Name="DateRangeSelector"
    Grid.Column="1"
    Margin="10 0 0 0"
    HorizontalAlignment="Left"
    VerticalAlignment="Center"
    AutomationProperties.AutomationId="AID_TaskListDateRangeSelector"
    DateRangeUpdatedCmd="{Binding Path=DateRangeSelectionUpdatedCommand}"
    FontSize="{StaticResource TaskListMenuFontSize}"
    RangeOptions="{Binding Path=DateRangeSelectionOptions, Mode=OneTime}"
    SelectedDateRange="{Binding Path=SelectedRange, Mode=TwoWay}"
    Visibility="{Binding Path=ShowFilterOptions, 
        Converter={StaticResource boolToVisibility}}"
    TodayDate="{Binding TodayDate, ElementName=DateRangeSelector}" />

---

UPDATE >>>

Ok, I think that I see what your problem is now. You are trying to data bind from your control to a view model property. What your Binding.Path will look like will depend on how your view model is 'connected' to your view. Assuming that an instance of your view model is set as the DataContext for your view, you would then be able to access the view model property like this:

TodayDate="{Binding DataContext.TodayDate, RelativeSource={RelativeSource 
    AncestorType={x:Type UserControl}}}" 

Of course, if your control is declared in MainWindow instead, then you would need to use the following syntax:

TodayDate="{Binding DataContext.TodayDate, RelativeSource={RelativeSource 
    AncestorType={x:Type MainWindow}}}"