如何加载具有与 RadComboBox 中预选的 ItemsSource 对象不同的属性值的 SelectedItem 对象

Question

我有一个在下拉列表中渲染的对象：

   [DataContract]
   public sealed class ConfiguredFileViewModel : Model
   {
       [DataMember] public string Path { get; set; }
       [DataMember] public TemplateViewModel Template { get; set; }
       [DataMember] public List<TemplateViewModel> AvailableTemplates { get; set; }
   }


  public class TemplateViewModel : INotifyPropertyChanged
  {
      private string _name;
      private List<KeyValueViewModel> _properties;

      // Rest of getters setters
  }

<!-- Foreach ConfiguredFile, render TextBlocks and TextInputs -->
 <ItemsControl ItemsSource="{Binding ConfiguredFiles}" Margin="10,20,0,0">
     <ItemsControl.ItemTemplate>
         <DataTemplate>
             <StackPanel Margin="10">
                 <!-- File Path -->
                 <TextBlock Text="{Binding Path}" FontWeight="Bold" VerticalAlignment="Center" Margin="0,0,0,5"/>

                 <!-- Telerik RadComboBox for Templates -->
                 <telerik:RadComboBox ItemsSource="{Binding AvailableTemplates}" 
                                      SelectedItem="{Binding Template, Mode=TwoWay}"
                                      DisplayMemberPath="Name"
                                      HorizontalAlignment="Left"
                                      Width="275"
                                      Margin="0,5"/>

                 <!-- Render Template Properties Based on Selected Template -->
                 <ItemsControl HorizontalAlignment="Left" Margin="0,0,0,0" ItemsSource="{Binding Template.Properties}">
                     <ItemsControl.ItemTemplate>
                         <DataTemplate>
                             <StackPanel Orientation="Horizontal" Margin="0,5">
                                 <TextBlock Text="{Binding Key}" VerticalAlignment="Center" Width="120"/>

                                 <TextBox Text="{Binding Value, Mode=TwoWay}" Width="150" HorizontalAlignment="Left" Margin="5,0"/>
                             </StackPanel>
                         </DataTemplate>
                     </ItemsControl.ItemTemplate>
                 </ItemsControl>
             </StackPanel>
         </DataTemplate>
     </ItemsControl.ItemTemplate>
 </ItemsControl>

当我填写

Properties

的

Template

并保存

ConfiguredFileViewModel

时，加载应用程序备份，我可以在调试器中看到，该对象有一个

Path

和一个更改后的

Template

 Properties

。但即使名称相同，UI 也不会显示下拉列表预选

Template

。

只有当我将

Template

设置为

AvailableTemplates

的对象时，它才会预选，但我不希望它加载默认属性。有人知道解决方法吗？

我尝试过：

• 使用

  SelectedValue

• IsSynchronizedWithCurrentItem

  ，但这只是更改了默认属性（为什么我的 ComboBox SelectedItem 为空？）

• Mode=TwoWay

  也没什么作用

Answer 1

我刚刚修改了

ConfiguredFileViewModel

类：

[DataContract]
public class ConfiguredFileViewModel : Model, INotifyPropertyChanged
{
    private string _path;
    private TemplateViewModel _template;
    private List<CustomKeyValue> _properties;

    [DataMember]
    public string Path
    {
        get => _path;
        set { _path = value; OnPropertyChanged(nameof(Path)); }
    }
    [DataMember]
    public TemplateViewModel SelectedTemplate // One of the default Templates
    {
        get => _template;
        set
        {
            if (_template != value)
            {
                _template = value;
                OnPropertyChanged(nameof(SelectedTemplate));

                var newKeys = _template?.Properties.Select(kv => kv.Key);
                var oldKeys = Properties?.Select(kv => kv.Key) ?? Enumerable.Empty<string>();

                if (!new HashSet<string>(newKeys).SetEquals(oldKeys))
                {
                    // Load template properties with default values when the template changes (= when keys become unequal)
                    Properties = _template?.Properties
                        .Select(kv => new CustomKeyValue { Key = kv.Key, Value = kv.Value })
                        .ToList();
                }

            }
        }
    }
    [DataMember]
    public List<CustomKeyValue> Properties // Changed or default properties
    {
        get => _properties;
        set { _properties = value; OnPropertyChanged(nameof(Properties)); }
    }

    [DataMember]
    public List<TemplateViewModel> AvailableTemplates { get; set; } // Templates with default properties
    
    // Rest of INotifyPropertyChanged code
}