綁定到屬性和元素值 - WPF綁定

Question

我有一個checkbox綁定到一個對象的屬性「IsValidCustomer」，我有一個listview持有一些客戶。 每當我的用戶在列表中選擇任何Customer，我希望CheckboxChecked屬性設置爲False，這意味着我的「IsValidCustomer」屬性也將自動設置爲False。有沒有使用WPF綁定來實現這一點的方法？

在這方面的任何幫助將高度appriciated。

問候

-Srikanth

Answer 1

• 首先確保你的觀點的Datacontext設置爲viewmodel實現了INotifyPropertyChangedinterface然後添加一個SelectedCustomer屬性，將舉行從ListView選擇Customer，

• 每次設置SelectedCustomer時，檢查它的價值，並設置IsValidCustomer屬性 這裏的全碼：

視圖模型

public class Customer 
{ 
    public String Name { get; set; } 
    public String Id { get; set; } 
} 
public partial class MainWindow : Window, INotifyPropertyChanged 
{ 
    private Customer _selectedCustomer; 
    public Customer SelectedCustomer 
    { 
     get 
     { 
      return _selectedCustomer; 
     } 

     set 
     { 
      if (_selectedCustomer == value) 
      { 
       return; 
      } 

      _selectedCustomer = value; 
      OnPropertyChanged(); 
      IsValidCustomer = (_selectedCustomer == null); 

     } 
    } 
    private ObservableCollection<Customer> _listCustomers; 
    public ObservableCollection<Customer> ListCustomers 
    { 
     get 
     { 
      return _listCustomers; 
     } 

     set 
     { 
      if (_listCustomers == value) 
      { 
       return; 
      } 

      _listCustomers = value; 
      OnPropertyChanged(); 
     } 
    } 
    private bool _isValidCustomer = false; 
    public bool IsValidCustomer 
    { 
     get 
     { 
      return _isValidCustomer; 
     } 

     set 
     { 
      if (_isValidCustomer == value) 
      { 
       return; 
      } 

      _isValidCustomer = value; 
      OnPropertyChanged(); 
     } 
    } 
    public MainWindow() 
    { 
     InitializeComponent(); 
    } 

    public event PropertyChangedEventHandler PropertyChanged; 

    [NotifyPropertyChangedInvocator] 
    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null) 
    { 
     PropertyChangedEventHandler handler = PropertyChanged; 
     if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName)); 
    } 
} 

和視圖

<StackPanel> 
    <CheckBox Content="IsValidCustomer" IsChecked="{Binding IsValidCustomer,Mode=TwoWay}"></CheckBox> 
    <ListView ItemsSource="{Binding ListCustomers}" SelectedItem="{Binding SelectedCustomer,Mode=TwoWay}"></ListView>   
</StackPanel> 

Answer 2

我相信你有這樣的事情在您的型號：

 private bool _IsValidCustomer; 

    public bool IsValidCustomer 
    { 
     get { return _IsValidCustomer; } 
     set 
     { 
      _IsValidCustomer= value; 
      PropertyChanged(this, new PropertyChangedEventArgs("IsValidCustomer")); 
     } 
    } 

設置該布爾屬性的綁定。

  <Style TargetType="ListViewItem"> 
       <Setter Property="IsSelected" Value="{Binding IsValidCustomer, Converter={StaticResource InverseBooleanConverter}}"/> 
      </Style> 

你的複選框將被綁定到這個也：

<CheckBox IsChecked="{Binding IsValidCustomer, Mode=TwoWay}"/> 

所以，我假設你開始與IsValidCustomer設置爲true。在選擇每一行時，您希望將其設置爲false。

您將需要此相反的布爾轉換器：

public class InverseBooleanConverter: IValueConverter 
{ 
    #region IValueConverter Members 

    public object Convert(object value, Type targetType, object parameter, 
     System.Globalization.CultureInfo culture) 
    { 
     if (targetType != typeof(bool)) 
      throw new InvalidOperationException("The target must be a boolean"); 

     return !(bool)value; 
    } 

    public object ConvertBack(object value, Type targetType, object parameter, 
     System.Globalization.CultureInfo culture) 
    { 
     throw new NotSupportedException(); 
    } 

    #endregion 
}