未能清除之前在單選按鈕上顯示的標籤單擊wpf

Question

我正在基於單選按鈕單擊動態生成標籤。那麼我已經成功做到了，但每次點擊一個按鈕時，它都會生成標籤，但不清除以前的狀態。下面是代碼：

XAML：

<Grid Grid.Row="0">      

     <ItemsControl ItemsSource="{Binding Children}"> 
      <ItemsControl.ItemTemplate> 
       <DataTemplate> 
        <StackPanel Orientation="Vertical" > 
         <RadioButton Content="{Binding RadioBase}" Margin="0,10,0,0" IsChecked="{Binding BaseCheck}" GroupName="SlotGroup" />        
        </StackPanel> 
       </DataTemplate> 
      </ItemsControl.ItemTemplate> 
     </ItemsControl>   
    </Grid> 

<Grid Grid.Row="1">    

     <ItemsControl ItemsSource="{Binding Children}" Grid.Column="0"> 
      <ItemsControl.ItemTemplate> 
       <DataTemplate> 
        <StackPanel> 
         <ItemsControl Visibility="{Binding IsRegisterItemsVisible, Converter={StaticResource BoolToVisibilityConv}}" ItemsSource="{Binding RegisterLabels}"> 
          <ItemsControl.ItemTemplate> 
           <DataTemplate> 
            <StackPanel HorizontalAlignment="Center" VerticalAlignment="Center" Margin="50,20,0,0"> 
             <TextBlock Text="{Binding}"/> 
            </StackPanel> 
           </DataTemplate> 
          </ItemsControl.ItemTemplate> 
         </ItemsControl> 
        </StackPanel> 
       </DataTemplate> 
      </ItemsControl.ItemTemplate> 
     </ItemsControl>    
    </Grid> 

FPGARadioWidgetViewModel類：此類的的DataContext在這裏設置

public ObservableCollection<FPGAViewModel> Children { get; set; } 

    public FPGARadioWidgetViewModel() 
    { 
     Children = new ObservableCollection<FPGAViewModel>(); 
     Children.Add(new FPGAViewModel() { RadioBase = "Base 0x0", ID = 0 }); 
     Children.Add(new FPGAViewModel() { RadioBase = "Base 0x40", ID = 1 }); 
     Children.Add(new FPGAViewModel() { RadioBase = "Base 0x80", ID = 2 }); 
     Children.Add(new FPGAViewModel() { RadioBase = "Base 0xc0", ID = 3 });    
    } 

FPGAViewModel類：

private bool sBaseCheck; 
    public bool BaseCheck 
    { 
     get { return this.sBaseCheck; } 
     set 
     { 
      this.sBaseCheck = value; 
      Generatelabels(this, ID); 
      this.OnPropertyChanged("BaseCheck"); 
     } 
    } 

    private static void Generatelabels(FPGAViewModel currentItem, int index) 
    { 
     int m_baseRegister = 0; 

     if (index == 0) 
     {     
      for (int i = 0; i < 0x40/8; i++) 
      { 
       int reg = (i * 8) + m_baseRegister; 
       currentItem.RegisterLabels[i] = "Reg 0x" + reg.ToString("X"); 
       currentItem.IsRegisterItemsVisible = true; 
      } 
     } 
     else if (index == 1) 
     { 
      m_baseRegister = 0x40 * index; 
      for (int i = 0; i < 0x40/8; i++) 
      { 
       int reg = (i * 8) + m_baseRegister; 
       currentItem.RegisterLabels[i] = "Reg 0x" + reg.ToString("X"); 
       currentItem.IsRegisterItemsVisible = true; 
      } 
     } 
     // Similarly for Index 2 and Index = 3 
    } 

    private string[] registerLabels = new string[8]; 
    public string[] RegisterLabels { get { return registerLabels; } } 

    private bool isRegisterItemsVisible = false; 
    public bool IsRegisterItemsVisible 
    { 
     get { return isRegisterItemsVisible; } 
     set 
     { 
      isRegisterItemsVisible = value; 
      OnPropertyChanged("IsRegisterItemsVisible"); 
      OnPropertyChanged("RegisterLabels"); 
     } 
    }  

單選按鈕上顯示8個標籤。當我點擊第二個單選按鈕時，它會顯示另一個8並且不清除前8個。基本上，一次只能顯示8個選定單選按鈕的標籤。這怎麼能實現？

Answer 1

我不確定，但可能WPF會因爲PropertyChanged爲RegisterLabels而發生混淆，因爲當數組對象本身沒有改變時，只有內容具有。

通常，如果你有在WPF已改變內容的集合，您使用的ObservableCollection相反，它支持INofityCollectionChanged告訴WPF，當它包含的項目已經改變（如你的Children做）

要麼，每次在GenerateLabels中創建一個新陣列，然後在最後將其分配給您的RegisterLabels屬性。

ps。爲什麼您的方法是靜態的？如果它只是一個普通的實例方法，它會更清潔，那麼您就不必通過currentItem和index。

EDIT：第二方法（替換陣列）的實施例

public string[] RegisterLabels { get; private set; } 

private void Generatelabels() 
{ 
    string[] labels = new string[8]; 
    int baseRegister = 0x40 * ID; 

    for (int i = 0; i < 8; i++) 
    { 
     int reg = (i * 8) + baseRegister; 
     labels[i] = "Reg 0x" + reg.ToString("X"); 
    } 

    RegisterLabels = labels; 
    OnPropertyChanged("RegisterLabels"); 
}