我正在使用Telerik UI在Xamarin上开发Android应用程序。
当尝试将属性绑定到RadListView中的Telerik ListViewTextCell时出现以下错误:
[0:] Binding: 'Author' property not found on 'Book', target property: 'Telerik.XamarinForms.DataControls.ListView.ListViewTextCell.Detail'
即使在最小的情况下也会发生这种情况。下面是一个示例,主要来自ListView文档本身。
PageTest.cs:
using System.Collections.Generic;
using System.ComponentModel;
using Xamarin.Forms;
using Telerik.XamarinForms.DataControls;
using Telerik.XamarinForms.DataControls.ListView;
namespace MyTelerikApp
{
[DesignTimeVisible(false)]
public partial class PageTest : ContentPage
{
public PageTest()
{
InitializeComponent();
}
protected override void OnAppearing()
{
base.OnAppearing();
var listView = new RadListView
{
ItemsSource = new ViewModel().Source,
ItemTemplate = new DataTemplate(() =>
{
var cell = new ListViewTextCell
{
TextColor = Color.Black,
DetailColor = Color.Gray,
};
cell.SetBinding(ListViewTextCell.TextProperty, new Binding(nameof(Book.Title)));
cell.SetBinding(ListViewTextCell.DetailProperty, new Binding(nameof(Book.Author)));
return cell;
}),
LayoutDefinition = new ListViewLinearLayout { ItemLength = 70 }
};
MainPageContent.Children.Add(listView);
}
}
}
public class Book
{
public string Title { get; set; }
public string Author { get; set; }
}
public class ViewModel
{
public ViewModel()
{
this.Source = new List<Book>{
new Book{ Title = "The Fault in Our Stars ", Author = "John Green"},
new Book{ Title = "Divergent", Author = "Veronica Roth"},
new Book{ Title = "Gone Girl", Author = "Gillian Flynn"},
new Book{ Title = "Clockwork Angel", Author = "Cassandra Clare"},
new Book{ Title = "The Martian", Author = "Andy Weir"},
new Book{ Title = "Ready Player One", Author = "Ernest Cline"},
new Book{ Title = "The Lost Hero", Author = "Rick Riordan"},
new Book{ Title = "All the Light We Cannot See", Author = "Anthony Doerr"},
new Book{ Title = "Cinder", Author = "Marissa Meyer"},
new Book{ Title = "Me Before You", Author = "Jojo Moyes"},
new Book{ Title = "The Night Circus", Author = "Erin Morgenstern"},
};
}
public List<Book> Source { get; set; }
}
PageText.xaml:
<?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:d="http://xamarin.com/schemas/2014/forms/design"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
x:Class="GeoGIS.views.PageTest">
<StackLayout x:Name="MainPageContent">
</StackLayout>
</ContentPage>
经过一些搜索之后,似乎有必要使用BindingContext,但是我也无法使它正常工作。
我没有从您的代码中找到BindingContext
。而且我想您把ContentPage
(XAML和C#)的两种用法混淆了。
[创建内容页面时,我们有两个选择(XAML
和C#
),如下所示:
1。在这种情况下,当我们选择ContentPage(c#)时,没有xaml。我们可以这样做:
public class TestPage1 : ContentPage
{
public TestPage1 ()
{
var listView = new RadListView
{
BackgroundColor = Color.White,
ItemsSource = new ViewModel().Source,
ItemTemplate = new DataTemplate(() =>
{
var cell = new ListViewTextCell
{
TextColor = Color.Black,
DetailColor = Color.Gray,
};
cell.SetBinding(ListViewTextCell.TextProperty, new Binding(nameof(Book.Title)));
cell.SetBinding(ListViewTextCell.DetailProperty, new Binding(nameof(Book.Author)));
return cell;
}),
LayoutDefinition = new ListViewLinearLayout { ItemLength = 70 },
};
Content = new StackLayout {
Children = {
listView
}
};
}
}
2。当我们选择ContentPage时,在这种情况下,代码具有xaml。我们可以这样做。
将以下代码放入您的xaml中
<StackLayout>
<telerikDataControls:RadListView ItemsSource="{Binding Source}" BackgroundColor="White" x:Name="listView">
<telerikDataControls:RadListView.BindingContext>
<local:ViewModel />
</telerikDataControls:RadListView.BindingContext>
<telerikDataControls:RadListView.ItemTemplate>
<DataTemplate>
<telerikListView:ListViewTextCell Text="{Binding Title}" Detail="{Binding Author}" TextColor="Black" DetailColor="Gray" />
</DataTemplate>
</telerikDataControls:RadListView.ItemTemplate>
<telerikDataControls:RadListView.LayoutDefinition>
<telerikListView:ListViewLinearLayout ItemLength="70" />
</telerikDataControls:RadListView.LayoutDefinition>
</telerikDataControls:RadListView>
</StackLayout>
并从您的代码中删除方法OnAppearing()
。
public partial class MainPage : ContentPage
{
public MainPage()
{
InitializeComponent();
//BindingContext = new ViewModel();
}
protected override void OnAppearing()
{
base.OnAppearing();
}
}
从上面的代码中,我们可以找到BindingContext,这是必需的。
<telerikDataControls:RadListView.BindingContext>
<local:ViewModel />
</telerikDataControls:RadListView.BindingContext>
而且我们也可以像这样绑定Context(任何人都可以。):
BindingContext = new ViewModel();