我們如何訪問Itemtemplate中的控件Silverlight

Question

我有一個列表框。我有一個項目模板和一個堆棧面板。 它在項目模板中有一個文本框和一個複選框。

有沒有一種方法，我可以訪問該複選框，啓用/禁用所選指標變化？

<UserControl.Resources> <DataTemplate x:Key="UserApplicationsTemplate"> <StackPanel Orientation="Horizontal" Margin="2" ToolTipService.Placement="Mouse" ToolTipService.ToolTip="{Binding Description, Mode=OneWay}"> <TextBlock Text="{Binding Mode=OneWay}" TextWrapping="Wrap" Width="100" DataContext="{Binding ApplicationName, Mode=OneWay}" /> <CheckBox x:Name="{Binding ApplicationName, Mode=OneWay}" Margin="5,0,0,0" Click="IsActive_Clicked" IsChecked="{Binding IsActive, Mode=OneWay}" Content="IsActive"/> </StackPanel> </DataTemplate> </UserControl.Resources>

<ListBox x:Name="lstbxUserApplications" Height="357" ItemsSource="{Binding Mode=OneWay}" SelectionMode="Single" ItemTemplate="{StaticResource UserApplicationsTemplate}" />

Answer 1

下面是使用單選按鈕解決方案：
http://leeontech.wordpress.com/2009/03/18/creating-radiobuttonlist/

它應該很容易將其更改爲複選框。

Answer 2

Assming你有你的ItemsSource綁定：

<ListBox x:Name="myList"> 
    <ListBox.ItemTemplate> 
     <DataTemplate> 
      <StackPanel Orientation="Horizontal"> 
       <CheckBox IsChecked="{Binding Check, Mode=TwoWay}" /> 
       <TextBlock Text="{Binding Name, Mode=TwoWay}" 
          Width="100" /> 
      </StackPanel> 
     </DataTemplate> 
    </ListBox.ItemTemplate> 
</ListBox> 

<Button x:Name="button1" 
     Content="Uncheck 2" 
     Click="button1_Click" /> 

你實際上並不需要改變CheckBox.IsChecked財產，但對你的ItemsSource值：

public partial class MainPage : UserControl 
    { 
     public MainPage() 
     { 
      InitializeComponent(); 
      this.Loaded += new RoutedEventHandler(MainPage_Loaded); 
     } 

     void MainPage_Loaded(object sender, RoutedEventArgs e) 
     { 
      myList.ItemsSource = ListInfo.getInfo(); 
     } 

     private void button1_Click(object sender, RoutedEventArgs e) 
     { 
      ListInfo item = myList.Items[1] as ListInfo; 
      item.Check = !item.Check; 
     } 
    } 

    public class ListInfo : INotifyPropertyChanged 
    { 
     private string name; 
     public string Name 
     { 
      get 
      { 
       return name; 
      } 
      set 
      { 
       name = value; 
       NotifyPropertyChange("Name"); 
      } 
     } 

     private bool check; 
     public bool Check 
     { 
      get 
      { 
       return check; 
      } 
      set 
      { 
       check = value; 
       NotifyPropertyChange("Check"); 
      } 
     } 

     public static ObservableCollection<ListInfo> getInfo() 
     { 
      ObservableCollection<ListInfo> data = new ObservableCollection<ListInfo>(); 
      data.Add(new ListInfo { Name = "Some text 1", Check = true }); 
      data.Add(new ListInfo { Name = "Some text 2", Check = false }); 
      data.Add(new ListInfo { Name = "Some text 3", Check = true }); 

      return data; 
     } 

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

     #region INotifyPropertyChanged Members 

     public event PropertyChangedEventHandler PropertyChanged; 

     #endregion 
} 

如果坐查看按鈕上Click事件處理程序，可以看到我所做的只是獲取項目並更改了值。這立即反映在用戶界面上。

更新：我看，這是你問的不是什麼。這裏有幾個想法：

你可以有一個事件處理程序的複選框：

<ListBox x:Name="myList"> 
    <ListBox.ItemTemplate> 
     <DataTemplate> 
      <StackPanel Orientation="Horizontal"> 
       <CheckBox IsChecked="{Binding Check, Mode=TwoWay}" 
          IsEnabled="True" 
          Content="{Binding Name, Mode=TwoWay}" 
          Click="CheckBox_Click" /> 
      </StackPanel> 
     </DataTemplate> 
    </ListBox.ItemTemplate> 
</ListBox> 

，並獲得該代碼後面的參考資料：

private void CheckBox_Click(object sender, RoutedEventArgs e) 
{ 
    CheckBox chk = sender as CheckBox; 
    chk.IsEnabled = false; 
} 

當然，這裏的問題如果您禁用複選框，您將無法訪問Click envent。

另一種選擇是使用VisualTreeHelper獲得關於你的CheckBox當在ListBox中的選擇變化：

private void myList_SelectionChanged(object sender, SelectionChangedEventArgs e) 
{ 
    ListBox list = sender as ListBox; 
    ListInfo current = list.SelectedItem as ListInfo; 

    List<CheckBox> checkBoxes = new List<CheckBox>(); 
    getCheckBoxes(list, ref checkBoxes); 

    foreach (CheckBox checkBox in checkBoxes) 
    { 
     if (checkBox.Content.ToString() == current.Name) 
     { 
      checkBox.Foreground = new SolidColorBrush(Colors.Red); 
     } 
    } 
} 

public void getCheckBoxes(UIElement parent, ref List<CheckBox> items) 
{ 
    int count = VisualTreeHelper.GetChildrenCount(parent); 
    if (count > 0) 
    { 
     for (int i = 0; i < count; i++) 
     { 
      UIElement child = VisualTreeHelper.GetChild(parent, i) as UIElement; 
      if (child.GetType() == typeof(CheckBox)) 
      { 
       items.Add(child as CheckBox); 
      } 
      getCheckBoxes(child, ref items); 
     } 
    } 
} 

這當然不是性能最好的選擇，但你獲得更多的靈活性。