WPF數據綁定不能通過XAML工作（僅通過代碼）

Question

當試圖通過XAML將ListView綁定到ObservableCollection時，ListView未更新，並且最初使用空值加載。

通過XAML

History.xaml.cs

DataContext = this; 

History.xaml：

<ListView x:Name="lvHistory" ItemsSource="{Binding Source=history}" BorderThickness="0" Margin="0,0,0,0" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Grid.Column="2" util:GridViewSort.AutoSort="True" SizeChanged="lvHistory_SizeChanged"> 

通過代碼

當操作的方式從代碼的結合，該綁定工作正常。

History.xaml

<ListView x:Name="lvHistory" BorderThickness="0" Margin="0,0,0,0" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Grid.Column="2" util:GridViewSort.AutoSort="True" SizeChanged="lvHistory_SizeChanged"> 

History.xaml.cs

DataContext = this; 
lvHistory.ItemsSource = history; 

只需通過代碼添加的ItemsSource和XAML刪除它，代碼工作正常。我錯過了什麼？我如何通過純XAML創建綁定？

歷史：

public ObservableCollection<LocateElement> history { get; private set; } 

代碼更新列表：

public void Update() 
    { 
     if (updater.IsBusy) updatePending = true; 
     else 
     { 
      searchValue = txtSearch.Text.Trim(); 
      updatePending = false; 
      updater.RunWorkerAsync(); 
     } 
    } 

    private void updateContent(object sender, DoWorkEventArgs e) 
    { 
     try 
     { 
      Globals.Variables.logger.Info("Locate History: Updating"); 

      using (var db = new Data.DataManager()) 
      { 
       var history = db.LocateHistory.Where(o => o.ReceivedBy == Globals.Variables.loginDetails.UserID); 

       e.Result = filterResults(history); 
      } 

     } 
     catch (Exception er) 
     { 
      Globals.Variables.logger.Error(er); 
     } 
    } 

    private void updateFinished(object sender, RunWorkerCompletedEventArgs e) 
    { 
     List<LocateElement> r = (List<LocateElement>)e.Result; 

     history.Clear(); 
     foreach (LocateElement l in r) 
     { 
      history.Add(l); 
     } 

     if (updatePending) Update(); 
     //else Wpf.Util.GridViewSort.ReapplySort(lvHistory); 
    } 

    private List<LocateElement> filterResults(IQueryable<LocateElement> list) 
    { 
     List<LocateElement> history = new List<LocateElement>(); 

     foreach (LocateElement l in list) 
     { 
      if (searchValue != "") 
      { 
       // Use the parameters to filter the results. 
       Regex reg = new Regex(WildcardToRegex(searchValue)); 


       if (reg.IsMatch(l.Serial) || reg.IsMatch(l.Asset) || reg.IsMatch(l.DeviceType) || reg.IsMatch(l.Company) || (l.ReceivedFrom != null && reg.IsMatch(l.ReceivedFrom.Name)) || (l.ReceivedTo != null && reg.IsMatch(l.ReceivedTo.Name)) || reg.IsMatch(l.Row) || reg.IsMatch(l.Shelf) || reg.IsMatch(l.Bin) || reg.IsMatch(l.DateReceived.ToString())) 
       { 
        history.Add(l); 
       } 
      } 
      else 
      { 
       history.Add(l); 
      } 
     } 

     return history; 
    } 

Answer 1

一個Binding的Source財產並不意味着你認爲這意味着什麼。改爲使用Path，或讓它假定您正在談論Path（默認）。這應該做到這一點。

<ListView ItemsSource="{Binding history}" ...> 

此外，如果你是設置你的構造外history屬性，它需要通知的屬性已更改。如果你只是在你的構造函數中設置它，你不需要，但是你可能想讓它支持readonly而不是自動獲取器/設置器。 （TrueEddie的解決方案描述了這個問題並提供瞭解決方案，以便將實際變量換出）。

Answer 2

當你將數據傳輸到歷史收集你需要確保你提升屬性更改事件。

例如：

public class MyViewModel : INotifyPropertyChanged 
    { 
     public event PropertyChangedEventHandler PropertyChanged; 

     private ObservableCollection<LocateElement> _history; 

     public ObservableCollection<LocateElement> history 
     { 
      get { return _history; } 
      set 
      { 
       if (_history != value) 
       { 
        _history = value; 

        RaisePropertyChanged("history"); 
       } 
      } 
     } 

     public MyViewModel() 
     { 
      _history = new ObservableCollection<LocateElement>(); 
     } 

     private void RaisePropertyChanged(string propertyName) 
     { 
      if (PropertyChanged != null) 
      { 
       PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); 
      } 
     } 
    }