Xamarin RadioBox Set groupName的列表从查看模型

Question

到目前为止，我发现的RadioButtons的所有示例都在页面的XAML中对值进行了硬编码。我希望从数据库中喂食（目前）的字符串列表，并遇到了GroupName的问题。

My data template for a radio display type:

            <DataTemplate x:Key="RadioTemplate">
                <StackLayout>
                    <Label 
                        Text="{Binding Name}"
                        Style="{StaticResource LabelStyle}">
                    </Label>
                    <ListView ItemsSource="{Binding Choices.Choices}">
                        <ListView.ItemTemplate>
                            <DataTemplate>
                                <ViewCell>
                                    <RadioButton Value="{Binding}"
                                            Content="{Binding}"
                                            GroupName="someGroupName"
                                            CheckedChanged="OnRadioChanged">
                                    </RadioButton>
                                </ViewCell>
                            </DataTemplate>
                        </ListView.ItemTemplate>
                    </ListView>
                </StackLayout>
            </DataTemplate>


MainPageViewModel.cs
using System;
using System.Collections.ObjectModel;
using System.Windows.Input;
using Xamarin.Forms;
using FieldDataTemplateSelectorSample.Validations;

namespace FieldDataTemplateSelectorSample
{
    public class MainPageViewModel : ValidationViewModelBase
    {
        public MainPageViewModel()
        {
            _fields = new ObservableCollection<FieldViewModel>();
        }

        private ObservableCollection<FieldViewModel> _fields;
        public ObservableCollection<FieldViewModel> Fields
        {
            get { return _fields; }
            set
            {
                _fields = value;
                RaisePropertyChanged();
            }
        }

        private bool _showValidationSummary;
        public bool ShowValidationSummary
        {
            get { return _showValidationSummary; }
            set
            {
                _showValidationSummary = value;
                RaisePropertyChanged();
            }
        }

        ICommand _submitCommand;
        public ICommand SubmitCommand
        {
            get => _submitCommand ?? (_submitCommand = new Command(ValidateAndSave));
        }

        private void ValidateAndSave(object obj)
        {
            ValidateAll();
            if (ErrorStateManager.HasError)
            {
                ShowValidationSummary = true;
            }
            else
            {
                ShowValidationSummary = false;
            }
        }
    }
}

using System.Collections.Generic;
using Xamarin.Forms;
using FieldDataTemplateSelectorSample.Validations;


namespace FieldDataTemplateSelectorSample
{
    public class FieldViewModel : ValidationViewModelBase
    {
        public FieldViewModel()
        {
            _choices = new ChoiceViewModel();
        }

        private string _value;

        public long Id { get; set; }
        public string Name { get; set; }
        public string Title { get; set; }
        public string Code { get; set; }
        public string Value 
        { 
            get
            {
                return _value;
            }           
            set
            {
                _value = value;
                RaisePropertyChanged();
                Validate();
            }
        }
        public string PlaceholderText { get; set; }
        public int SortOrder { get; set; }
        public string DisplayType { get; set; }
        public bool IsReadOnly { get; set; }
        public bool IsEnabled { get; set; }

        private ChoiceViewModel _choices;
        public ChoiceViewModel Choices
        {
            get 
            { 
                return _choices; 
            }
            set 
            { 
                _choices = value; 
                RaisePropertyChanged(); 
            }
        }

        void OnChoicesRadioButtonCheckedChanged(object sender, CheckedChangedEventArgs e)
        {
            // what else do we need to do?  Update value?
            
            RaisePropertyChanged();
        }
    }
}

using System;
using System.Collections.Generic;
using System.Text;

namespace FieldDataTemplateSelectorSample
{
    public class ChoiceViewModel
    {
        public ChoiceViewModel()
        {
            Choices = new List<string>();
        }

        public string Code { get; set; }
        public List<string> Choices { get; set; }
    }
}

只要我在ViewCell中的RadioButton进行了对groupName的编码，一切都可以使用，但是我最终会为页面上的每个单个单个单个单选按钮提供一个组名称。我已经尝试在模板中将属性添加到堆栈：

<StackLayout RadioButtonGroup.GroupName="someGroup">

将其从RadioButton中取出，但是当我将断点放在OnradioChanged中时，GroupName以NULL为单位。

我想将ChoiceViewModel中的代码属性用作组名称，但尚未获得相对绑定。感谢任何帮助或不同方法进行数据定位板的帮助。

Answer 1

您可以使用可约束的堆栈layout，这将使您对容器更多控制

<StackLayout>
    <Label Text="{Binding Name}" Style="{StaticResource LabelStyle}" />
    <StackLayout RadioButtonGroup.GroupName="{Binding Name}"      
           BindableLayout.ItemsSource="{Binding Choices.Choices}" >
       <BindableLayout.ItemTemplate>
         <DataTemplate>
           <ViewCell>
               <RadioButton Value="{Binding}" Content="{Binding}"
                   CheckedChanged="OnRadioChanged" />
           </ViewCell>
         </DataTemplate>
      </BindableLayout.ItemTemplate>
  </StackLayout>
</StackLayout>