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Silverlight 4:如何切换控件可见性

visibility silverlight-4.0 binding mvvm silverlight

8

Budda · 技术社区 · 15 年前

我正在Silverlight应用程序中使用MVVM。当控件可见性需要由数据管理时,我将其“可见性”属性连接到对象的相应属性:

XAML编号:

<TextBlock Text="Price" Visibility="{Binding PriceVisibility, Mode=OneWay}"/>
<TextBox Text="{Binding TicketPrice, Mode=TwoWay}" Visibility="{Binding PriceVisibility, Mode=OneWay}"/>

public string PriceVisibility { get { return PriceVisible ? "Visible" : "Collapsed"; } }

但从我的角度来看,返回Visibility属性的字符串表示并不是最好的方法。

请问有没有更好的办法?

2 回复 | 直到 15 年前

1

9

Rohan West 15 年前

我只是用反射器检查了P中的类型转换器RecentationFramework.dll

已经有一个实现可以在布尔值和可见性之间转换。您应该能够在silverlight应用程序中使用它。

public sealed class BooleanToVisibilityConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        bool flag = false;
        if (value is bool)
        {
            flag = (bool) value;
        }
        else if (value is bool?)
        {
            bool? nullable = (bool?) value;
            flag = nullable.HasValue ? nullable.Value : false;
        }
        return (flag ? Visibility.Visible : Visibility.Collapsed);
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        return ((value is Visibility) && (((Visibility) value) == Visibility.Visible));
    }
}

2

5

Bill the Lizard 14 年前

public class BoolVisibilityConverter : IValueConverter{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture){
        bool isVisible = (bool)value;
        return isVisible ? System.Windows.Visibility.Visible : System.Windows.Visibility.Collapsed;
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture){
        System.Windows.Visibility currVisibility = (System.Windows.Visibility)value;
        return (currVisibility == System.Windows.Visibility.Visible);
    }
}

现在要使用它,您需要将它作为资源添加到XAML代码中。

<UserControl.Resources>
    <Helpers:BoolVisibilityConverter x:Key="boolVisibilityConverter" />
</UserControl.Resources>

<TextBlock Text="Price" Visibility="{Binding PriceVisibility, Mode=OneWay, Converter={StaticResource boolVisibilityConverter}}"/>

<TextBox Text="{Binding TicketPrice, Mode=TwoWay}" Visibility="{Binding PriceVisibility, Mode=OneWay, Converter={StaticResource boolVisibilityConverter}}"/>