绑定到POCO列表时,指定的强制转换无效

Question

好的,我有以下观点:

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="BoomSauce.MainPage">
  <ListView ItemsSource="{Binding Model.MyPocos}">
    <ListView.ItemTemplate>
      <DataTemplate>
        <Label Text="{Binding MyString}"></Label>
      </DataTemplate>
    </ListView.ItemTemplate>
  </ListView>
</ContentPage>

此视图的BindingContext是以下ViewModel:

public class MainViewModel
{
    public MainModel Model { get; set; }
}

这是MainModel:

public class MainModel
{
    public List<MyPoco> MyPocos { get; set; }
}

这是MyPoco:

public class MyPoco
{
    public string MyString { get; set; }
    public int MyInt { get; set; }
}

这是App()中发生的事情

MainPage = new MainPage();

var viewModel = new MainViewModel
{
    Model = new MainModel
    {
        MyPocos = new List<MyPoco>()
        {
            new MyPoco() { MyInt = 1, MyString = "a" }, 
            new MyPoco() { MyInt = 2, MyString = "b" }, 
            new MyPoco() { MyInt = 3, MyString = "c" }, 
            new MyPoco() { MyInt = 4, MyString = "d" }, 
            new MyPoco() { MyInt = 5, MyString = "e" }
        }
    }
};

MainPage.BindingContext = viewModel;

真的没别的,我得到以下异常:

指定演员表无效.

但是没有内部异常,也没有更多的上下文,据我所知,我正在做正确的事情.

绑定到字符串列表工作正常,当我用任何其他对象替换出错的时候.

关于我哪里出错的任何想法？

谢谢

Answer 1

转而你不能将Label直接放在DataTemplate中,而是必须将它嵌套在ViewCell中,如下所示:

<ViewCell>
    <ViewCell.View>
        <Label Text="{Binding MyString}" />
    </ViewCell.View>
</ViewCell>

谜团已揭开.