如何绑定Func从视图模型到XAML中的依赖属性

本文关键字：模型 视图 XAML 属性 依赖 绑定 Func 何绑定 | 更新日期: 2023-09-27 18:10:27

我在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Binding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"  />

和视图模型中的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，但是依赖属性——theFilter——仍然为空。

做这个的语法是什么?这能做到吗?

编辑# 1。我意识到xaml需要属性来绑定，那么函数怎么能作为"属性"传递?

TIA

如何绑定Func<T,T,T>从视图模型到XAML中的依赖属性

更改TheFilter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);

将视图模型中的TheFilter类型从Func<View_Small_Company, string, bool>更改为Func<object, string, bool>

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