我有以下转换器:
公共类 InverseBooleanConverter : IValueConverter { #region IValueConverter 成员
public object Convert(object value, Type targetType, object parameter,
System.Globalization.CultureInfo culture)
{
try
{
if (targetType != typeof(bool))
throw new InvalidOperationException("The target must be a boolean");
}
catch(Exception ex)
{
int x = 1;
}
return !(bool)value;
}
public object ConvertBack(object value, Type targetType, object parameter,
System.Globalization.CultureInfo culture)
{
throw new NotSupportedException();
}
#endregion
}
我正在尝试像这样使用它来控制基于代码隐藏属性“CanShowResults”的列表视图的 IsVisible 和页面上的活动指示器:
<ListView x:Name="listView" BackgroundColor="White" SeparatorColor="#e0e0e0" IsVisible="False">
<ListView.Triggers>
<MultiTrigger TargetType="ListView">
<MultiTrigger.Conditions>
<BindingCondition Binding="{Binding Source={x:Reference retrievingActivity}, Path=IsRunning, Converter={StaticResource boolInvert}}" Value="true" />
<BindingCondition Binding="{Binding Path=CanShowResults}" Value="True" />
</MultiTrigger.Conditions>
<Setter Property="IsVisible" Value="True" />
</MultiTrigger>
</ListView.Triggers>
<ListView.ItemTemplate>
. . . . .
我在 Convert 方法中遇到异常。我已经搜索了文档,有没有人看到我做错了什么?