如何根據綁定變量的值選擇ComboBox項目？

Question

我想問一下，如何根據綁定變量的值選擇Combobox項目。例如綁定布爾變量性別綁定值真到男性和假到女？

<ComboBox> 
    <ComboBoxItem Content="male"/>  <- select if true 
    <ComboBoxItem Content="female" />  <- select if false 
</ComboBox> 

Answer 1

試試這個例子：

<RadioButton Name="Female" 
      Content="Female" 
      Margin="0,0,0,0" /> 

<RadioButton Name="Male" 
      Content="Male" 
      Margin="0,20,0,0" /> 

<ComboBox Width="100" Height="25"> 
    <ComboBoxItem Content="Male" 
        IsSelected="{Binding Path=IsChecked, 
             ElementName=Male}" />   

    <ComboBoxItem Content="Female" 
        IsSelected="{Binding Path=IsChecked, 
             ElementName=Female}" />     
</ComboBox> 

隨着越來越多的通用解決方案，您可以使用Converter：

提供一種方法來定製邏輯應用到綁定。

例子：

XAML

<Window x:Class="MyNamespace.MainWindow" 
     xmlns:this="clr-namespace:MyNamespace" 

    <Window.Resources> 
     <this:MaleFemaleConverter x:Key="MaleFemaleConverter" /> 
    </Window.Resources> 

    <ComboBox Width="100" 
       Height="25" 
       SelectedIndex="{Binding Path=IsChecked, <--- Here can be your variable 
             ElementName=SomeElement, 
             Converter={StaticResource MaleFemaleConverter}}"> 

     <ComboBoxItem Content="Male" /> 
     <ComboBoxItem Content="Female" />     
    </ComboBox>  

Code-behind

public class MaleFemaleConverter : IValueConverter  
{   
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)   
    {    
     bool Value = (bool)value; 

     if (Value == true) 
     { 
      return 1; 
     } 

     return 0; 
    } 

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture) 
    { 
     return DependencyProperty.UnsetValue; 
    }    
}