c# - 如何从 View 模型将 Func<T,T,T> 绑定(bind)到 XAML 中的依赖属性？

Question

我的 AutoFilteredComboBox 中有一个依赖属性:

 public Func<object, string, bool> theFilter
            {
                get { return (Func<object, string, bool>)GetValue(theFilterProperty); }
                set { SetValue(theFilterProperty, value); }
            }

            // Using a DependencyProperty as the backing store for theFilter.  This enables animation, styling, binding, etc...
            public static readonly DependencyProperty theFilterProperty =
                DependencyProperty.Register(
                "theFilter", 
                typeof(Func<object, string, bool>), 
                typeof(AutoFilteredComboBox), 
                new UIPropertyMetadata(null));

XAML 中的绑定(bind)是:

 <wc:AutoFilteredComboBox 
                  ItemsSource="{Binding PrimaryInsurance.Companies}"
                  ItemTemplate="{StaticResource CompanyTemplate}"
                  IsEditable="True"
                  IsTextSearchEnabled="True" 
                  TextSearch.TextPath="Companyname"
                  IsTextSearchCaseSensitive="False" 
                  theFilter="{Binding PrimaryInsurance.TheFilter}"  
                  Height="20" HorizontalAlignment="Left" Margin="162,235,0,0" VerticalAlignment="Top" Width="411"  />

View 模型中的 TheFilter 是:

 public Func<View_Small_Company, string, bool> TheFilter = (o, prefix) => o.Companyname.StartsWith(prefix);

所有编译都没有困难，但依赖属性 -- theFilter -- 仍然为空。

执行此操作的语法是什么？可以吗？

编辑#1。我意识到 xaml 需要绑定(bind)属性，那么一个函数怎么能 作为“属性”传递？

TIA

Answer 1

将 TheFilter 更改为属性:

public Func<View_Small_Company, string, bool> TheFilter { get; set; }

并在构造函数中设置:

TheFilter = (o, prefix) => ((View_Small_Company)o).Companyname.StartsWith(prefix);

从 Func<View_Small_Company, string, bool> 更改 View 模型中的 TheFilter 类型至 Func<object, string, bool>