DisplayMemberPath在設置爲其他內容後恢復爲Name

Question

因此，我正在使用MVVM結構向用戶顯示數據和修改它的應用程序。我目前遇到的問題是這樣的：

從RadGridView中選擇一個實體後，我添加該用戶查看ObservableCollection的成員。然後我看到RadListBox的get填充（意味着我可以懸停在該項目上），但沒有顯示任何內容。對象是我從服務引用的DataContract。我嘗試了許多修補程序，但無濟於事。

有一次我開始使用Snoop，並注意到無論我將DisplayMemberPath設置爲DisplayMemberPath的值是否始終爲「Name」。當我在Snoop中時，如果將值DisplayMemberPath更改爲FirstName，則名稱會在我的WPF應用程序中彈出。

我一直在盯着這一段時間，可能只是需要一組新的眼睛。下面是相關代碼：

XAML代碼：

<Grid MinHeight="70"> 
    <TextBlock Text="No Members viewed" 
      FontWeight="Bold" 
      HorizontalAlignment="Center" 
      VerticalAlignment="Center" 
      Visibility="{Binding TextBlockVisibility, FallbackValue=Visible, Mode=OneWay}"> 
    </TextBlock> 
    <telerik:RadListBox Name="uRecenetlyViewMembersListBox" 
      DataContext="{Binding MemberInfo}" 
         SelectionMode="Single" 
      DisplayMemberPath="{Binding FirstName}" 
         ItemsSource="{Binding RecentlyViewedMembers}" 
         SelectedItem="{Binding SelectedRecentlyViewedMember,Mode=TwoWay}" 
         Visibility="{Binding WorkingListNoRecordsVisibility, FallbackValue=Visible, Mode=OneWay}" 
         MouseDoubleClick="uRecenetlyViewMembersListBox_MouseDoubleClick"> 
    <i:Interaction.Triggers> 
     <i:EventTrigger EventName="SelectionChanged"> 
     <i:InvokeCommandAction Command="{Binding RecentlyViewedSelectionChanged}"> 
     </i:InvokeCommandAction> 
     </i:EventTrigger> 
    </i:Interaction.Triggers> 
    </telerik:RadListBox> 
</Grid> 

2/11編輯：所以我刪除了DataContext的，因爲它是目前還不清楚，如果它甚至曾作爲上下文指向正確的視圖模型。並更改了DisplayMemberPath並刪除了綁定。

<Grid MinHeight="70"> 
    <TextBlock Text="No Members viewed" 
      FontWeight="Bold" 
      HorizontalAlignment="Center" 
      VerticalAlignment="Center" 
      Visibility="{Binding TextBlockVisibility, FallbackValue=Visible, Mode=OneWay}"> 
    </TextBlock> 
    <telerik:RadListBox Name="uRecenetlyViewMembersListBox" 
         SelectionMode="Single" 
         DisplayMemberPath="FirstName" 
         ItemsSource="{Binding RecentlyViewedMembers}" 
         SelectedItem="{Binding SelectedRecentlyViewedMember,Mode=TwoWay}" 
         Visibility="{Binding WorkingListNoRecordsVisibility, FallbackValue=Visible, Mode=OneWay}" 
         MouseDoubleClick="uRecenetlyViewMembersListBox_MouseDoubleClick"> 
    <i:Interaction.Triggers> 
     <i:EventTrigger EventName="SelectionChanged"> 
     <i:InvokeCommandAction Command="{Binding RecentlyViewedSelectionChanged}"> 
     </i:InvokeCommandAction> 
     </i:EventTrigger> 
    </i:Interaction.Triggers> 
    </telerik:RadListBox> 
</Grid> 

和C＃代碼：

private const UInt16 recentlyViewedMemberCapacity = 10; 
private ObservableCollection<Member> recentlyViewedMembers; 
public ObservableCollection<Member> RecentlyViewedMembers 
{ 
    get { return this.recentlyViewedMembers; } 
    set 
    { 
     if (value != recentlyViewedMembers) 
     { 
      this.recentlyViewedMembers = value; 
      //ugly & inefficient: needs refactoring 
      //recentlyViewedMembers = (ObservableCollection<RecentlyViewedMember>)recentlyViewedMembers.OrderByDescending(item => item.DateAdded); 
      while (recentlyViewedMembers.Count > recentlyViewedMemberCapacity) 
       recentlyViewedMembers.RemoveAt(recentlyViewedMemberCapacity); 
      this.RaisePropertyChanged(() => this.RecentlyViewedMembers); 
      ValidateWorkingListVisibility(); 
     } 
    } 
} 

這裏是DataContract從服務返回的，只有必要的組件：

[DataContract(Name = "Member")] 
public class Member : INotifyPropertyChanged 
{ 
    public Member(); 

    [DataMember(Order = 0)] 
    public string FirstName { get; set; } 

    public event PropertyChangedEventHandler PropertyChanged; 
} 

Answer 1

嘗試設置DisplayMemberPath以硬編碼的屬性名稱，而不是結合：

DisplayMemberPath="FirstName" 

在標準WPF的列表框中，DisplayMemberPath應該設置爲要顯示的路徑（表示屬性名稱），而不是值。所以在我的理解中，即使綁定起作用，它也會將DisplayMemberPath設置爲值FirstName屬性而不是屬性名稱。

希望這也適用於telerik的RadListBox。