英文:
How to get properties from a list of objects binded to a CarouselView in .NET MAUI
问题
我有一个对象列表绑定到 CarouselView。在 CarouselView 内部，有一个简单的 DataTemplate，其中包含一些标签，它们应该绑定到对象的属性。然而，这些属性未被识别。
我正在使用 CommunityToolKit.Mvvm 来实现一个简单的 MVVM 解决方案。
我得到的错误是在第 16 行的视图中：
Error XFC0045 Binding: Property "Name" not found on "MauiTest.ViewModels.MainViewModel".
错误起源于以下行：
<Label Text="{Binding Path=Name}" />
视图：
<?xml version="1.0" encoding="utf-8" ?><ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"x:Class="MauiTest.MainPage"xmlns:vm="clr-namespace:MauiTest.ViewModels"x:DataType="vm:MainViewModel"><StackLayout><CarouselView BindingContext="{Binding Models}" ><CarouselView.ItemTemplate><DataTemplate><ContentView><StackLayout ><Label Text="{Binding Path=Name}" /><Label Text="{Binding Path=Description}" /></StackLayout></ContentView></DataTemplate></CarouselView.ItemTemplate></CarouselView></StackLayout></ContentPage>
模型：
public partial class TestModel : ObservableObject{[ObservableProperty]private string m_name;[ObservableProperty]private string m_description;public TestModel(string name, string description){Name = name;Description = description;}}
视图模型：
public partial class MainViewModel : ObservableObject{[ObservableProperty]private List<TestModel> m_models;public MainViewModel(){Models = new List<TestModel>{new TestModel("name1", "test1"),new TestModel("name2", "test2")};}}
英文:
I have a list of objects binded to a CarouselView. Inside the CarouselView is a simple DataTemplate containing some labels that are supposed to be binded to the properties of the object. However the properties are not recognized.
I am using CommunityToolKit.Mvvm for a simple MVVM solution.
The error I am getting is in the View on Line 16:
Error XFC0045 Binding: Property "Name" not found on "MauiTest.ViewModels.MainViewModel".
Line that the error originates from:
<Label Text="{Binding Path=Name}" />
View:
<?xml version="1.0" encoding="utf-8" ?><ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"x:Class="MauiTest.MainPage"xmlns:vm="clr-namespace:MauiTest.ViewModels"x:DataType="vm:MainViewModel"><StackLayout><CarouselView BindingContext="{Binding Models}" ><CarouselView.ItemTemplate><DataTemplate><ContentView><StackLayout ><Label Text="{Binding Path=Name}" /><Label Text="{Binding Path=Description}" /></StackLayout></ContentView></DataTemplate></CarouselView.ItemTemplate></CarouselView></StackLayout></ContentPage>
Model:
public partial class TestModel : ObservableObject{[ObservableProperty]private string m_name;[ObservableProperty]private string m_description;public TestModel(string name, string description){Name = name;Description = description;}}
ViewModel:
public partial class MainViewModel : ObservableObject{[ObservableProperty]private List<TestModel> m_models;public MainViewModel(){Models = new List<TestModel>{new TestModel("name1", "test1"),new TestModel("name2", "test2")};}}
答案1
得分: 0
你可以尝试以下的MVVM方式：
在XAML中，你可以将ItemsSource属性设置为Models
<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"x:Class="GetProperties75380426.MainPage"xmlns:vm="clr-namespace:GetProperties75380426.ViewModel"><StackLayout><CarouselView ItemsSource="{Binding Models}" ><CarouselView.ItemTemplate><DataTemplate><ContentView><StackLayout ><Label Text="{Binding Path=Name}" /><Label Text="{Binding Path=Description}" /></StackLayout></ContentView></DataTemplate></CarouselView.ItemTemplate></CarouselView></StackLayout></ContentPage>
在.cs文件中，设置页面的BindingContext为MainViewModel
public MainPage(){InitializeComponent();this.BindingContext = new MainViewModel();}
欲了解更多信息，你可以参考使用数据填充 CarouselView。
希望对你有所帮助。
英文:
You could try the following MVVM way:
In xaml, you could set the ItemsSource property to Models
<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"x:Class="GetProperties75380426.MainPage"xmlns:vm="clr-namespace:GetProperties75380426.ViewModel"><StackLayout><CarouselView ItemsSource="{Binding Models}" ><CarouselView.ItemTemplate><DataTemplate><ContentView><StackLayout ><Label Text="{Binding Path=Name}" /><Label Text="{Binding Path=Description}" /></StackLayout></ContentView></DataTemplate></CarouselView.ItemTemplate></CarouselView></StackLayout>
In .cs file, set the BindingContext of the page, that is the MainViewModel
public MainPage(){InitializeComponent();this.BindingContext = new MainViewModel();}
For more info, you could refer to Populate a CarouselView with data.
Hope it works for you.
答案2
得分: 0
错误消息指出它正在尝试在 MainViewModel 上查找属性 Name。
它在那里寻找（而不是在 TestModel 中），是因为这个 XAML 代码：
x:DataType="vm:MainViewModel"
一旦在 XAML 文件中添加了 任何 x:DataType，你就必须在它改变的任何地方添加正确的 x:DataType。
你可以有两种不同的修复方式：
- 要么：从 XAML 文件中删除所有
x:Datatype。 - 要么：添加缺失的
x:Datatype：
<ContentView x:DataType="PutCorrectNamespaceHere.TestModel">
注意：未经测试。我不确定这是否是放置缺失的 x:DataType 的正确位置。
英文:
The error message says that it is trying to find property Name on MainViewModel.
The reason it is looking there (instead of in TestModel), is this xaml:
x:DataType="vm:MainViewModel"
As soon as you add any x:DataType to a xaml file, you have to add the correct x:DataType, anywhere it changes.
There are two different ways you can fix:
- Either: remove all
x:Datatypes from the xaml file. - Or: add the missing
x:Datatype:
<ContentView x:DataType="PutCorrectNamespaceHere.TestModel">
NOTE: Not tested. I'm not sure that is the correct line to put the missing x:DataType.
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