绑定：使用 MVVM 在 Xamarin.forms 中找不到属性

Question

XFC0045 绑定：在“Page_Navigation.ViewModels.ThirdPageViewModel”上找不到属性“Tittle”。 从该区域获取错误 - Page_Navigation\Views\ThirdPage.xaml

using Xamarin.Forms;

namespace Page_Navigation.ViewModels
{
    public class ThirdPageViewModel : BindableObject
    {
        public ObservableCollection<Matches> MatchesList { get; set; }
        
        public ThirdPageViewModel()
        {
            MatchesList = new ObservableCollection<Matches>();
            MatchesList.Add(new Matches { Tittle = "Tittle 1", Description = "Description 1" });
            MatchesList.Add(new Matches { Tittle = "Tittle 2", Description = "Description 2" });
            MatchesList.Add(new Matches { Tittle = "Tittle 3", Description = "Description 3" });
            MatchesList.Add(new Matches { Tittle = "Tittle 4", Description = "Description 4" });
        }
    }

    public class Matches
    {
        public string Tittle { get; set; }
        public string Description { get; set; }
    }
}

 <?xml version="1.0" encoding="utf-8"?> <ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" xmlns:VM="clr-namespace:Page_Navigation.ViewModels" x:DataType="VM:ThirdPageViewModel" x:Class="Page_Navigation.Views.ThirdPage" NavigationPage.HasNavigationBar="True" NavigationPage.HasBackButton="True" Title="Third Page"> <ContentPage.BindingContext> <VM:ThirdPageViewModel/> </ContentPage.BindingContext> <ContentPage.Content> <ListView ItemsSource="{Binding MatchesList}"> <ListView.ItemTemplate> <DataTemplate> <ViewCell> <Grid HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand"> <Label Text="{Binding Tittle}"/> <Label Text="{Binding Description}"/> </Grid> </ViewCell> </DataTemplate> </ListView.ItemTemplate> </ListView> </ContentPage.Content> </ContentPage>

我不知道为什么会出现这个异常。 我正在使用 VS2019 和 Xamarin.forms 4.8.0.1451

Answer 1

您必须删除x:DataType属性，因为它与 Compiled Bindings 相关，并且您已经为 viewmodel 定义了 BindingContext。

在此处查看 XF 编译绑定： Xamarin.Forms 编译绑定

Answer 2

最佳选择：将新的附加 x:DataType 添加到 DataTemplate 标记

                <DataTemplate  x:DataType="VM:Matches" >
                    <ViewCell>
                        <Grid HorizontalOptions="FillAndExpand"
                              VerticalOptions="FillAndExpand">
                            <Label Text="{Binding Tittle}"/>
                            <Label Text="{Binding Description}"/>
                        </Grid>
                    </ViewCell>
                </DataTemplate>

它正在提高数据绑定性能