您可以将可空布尔值绑定到单选按钮上,但需要通过转换器进行操作。
首先声明您的变量:
private bool? answer;
public bool? Answer
{
get { return answer; }
set
{
answer = value;
if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs("Answer"));
}
}
并将其初始化为 null
。
然后在 XAML 中:
<Window.Resources>
<local:BooleanConverter x:Key="BooleanConverter"/>
</Window.Resources>
<StackPanel Grid.Row="1">
<RadioButton Content="I Agree"
IsChecked="{Binding Answer,
Converter={StaticResource BooleanConverter},
ConverterParameter='true', Mode=TwoWay}" />
<RadioButton Content="I Disagree"
IsChecked="{Binding Answer,
Converter={StaticResource BooleanConverter},
ConverterParameter='false', Mode=TwoWay}" />
</StackPanel>
最后是您的转换器:
class BooleanConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
var test = (bool?)value;
var result = bool.Parse((string)parameter);
if (test == result)
{
return true;
}
return false;
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
var result = bool.Parse((string)parameter);
return result;
}
}
这将单选按钮绑定到 Answer
,并说明只有在值为true
时才会选中第一个,当答案是false
时才会选中第二个。然后您可以在允许用户继续之前检查Answer
不为空。