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XAMLには4つの画像があります。

<Image Visibility="Collapsed" Name="LeftArrow" Height="20" Width="20"></Image>
<Image Visibility="Collapsed" Name="RightArrow" Height="20" Width="20"></Image>
<Image Visibility="Collapsed" Name="TopArrow" Height="20" Width="20"></Image>
<Image Visibility="Collapsed" Name="BottomArrow" Height="20" Width="20"></Image>

そして私のコードビハインドでは、他のすべての画像の1つが次のように表示されたときに、他のすべての画像を折りたたむスイッチケースがあります。

switch (ElementInfoCollection[pos].ArrowDirection)
{
    case ArrowDirection.Left:
        LeftArrow.Visibility = Visibility.Visible;
        RightArrow.Visibility = Visibility.Collapsed;
        TopArrow.Visibility = Visibility.Collapsed;
        BottomArrow.Visibility = Visibility.Collapsed;
        break;
    case ArrowDirection.Right:
        LeftArrow.Visibility = Visibility.Collapsed;
        RightArrow.Visibility = Visibility.Visible;
        TopArrow.Visibility = Visibility.Collapsed;
        BottomArrow.Visibility = Visibility.Collapsed;
        break;
    case ArrowDirection.Top:
        LeftArrow.Visibility = Visibility.Collapsed;
        RightArrow.Visibility = Visibility.Collapsed;
        TopArrow.Visibility = Visibility.Visible;
        BottomArrow.Visibility = Visibility.Collapsed;
        break;
    case ArrowDirection.Bottom:
        LeftArrow.Visibility = Visibility.Collapsed;
        RightArrow.Visibility = Visibility.Collapsed;
        TopArrow.Visibility = Visibility.Collapsed;
        BottomArrow.Visibility = Visibility.Visible;
        break;
    default:
        LeftArrow.Visibility = Visibility.Collapsed;
        RightArrow.Visibility = Visibility.Collapsed;
        TopArrow.Visibility = Visibility.Collapsed;
        BottomArrow.Visibility = Visibility.Collapsed;
        break;
}

明らかに、これは非常に馬鹿げた方法なので、画像の1つが分離コードで表示されるように設定されている場合に、画像を折りたたむ方法を知りたいですか？これは私がこれまでに思いついたものです：

<UserControl.Resources>
    <Style x:Key="ArrowSwitch" TargetType="{x:Type Image}">
        <Style.Triggers>
            <DataTrigger >
                <Setter Property="Image.Visibility" Value="Collapsed"></Setter>
            </DataTrigger>
            <DataTrigger>
                <Setter Property="Image.Visibility" Value="Visible"></Setter>
            </DataTrigger>
        </Style.Triggers>
    </Style>
</UserControl.Resources>
4

2 に答える 2

3

これは同じコードですが、はるかに短いです。

switch (ElementInfoCollection[pos].ArrowDirection)
{
    LeftArrow.Visibility = Visibility.Collapsed;
    RightArrow.Visibility = Visibility.Collapsed;
    TopArrow.Visibility = Visibility.Collapsed;
    BottomArrow.Visibility = Visibility.Collapsed;

    case ArrowDirection.Left: LeftArrow.Visibility = Visibility.Visible; break;
    case ArrowDirection.Right: RightArrow.Visibility = Visibility.Visible; break;
    case ArrowDirection.Top: TopArrow.Visibility = Visibility.Visible; break;
    case ArrowDirection.Bottom: BottomArrow.Visibility = Visibility.Visible; break;
    default: break;
}
于 2013-03-27T09:09:26.037 に答える
1

データバインディングを使用する場合は、ArrowDirectionをVisibility値にマップするコンバーターを利用できます。

public class DirectionVisibilityConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        ArrowDirection target;
        ArrowDirection current;
        try
        {
            current = (ArrowDirection)value;
        }
        catch (Exception)
        {
            return null;
        }
        if (Enum.TryParse(parameter.ToString(), out target))
        {
            if (current == target)
                return Visibility.Visible;
            else
                return Visibility.Collapsed;
        }
        return null;
    }

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

そして、次のようにXAMLで使用します。

<Window.Resources>
    <local:DirectionVisibilityConverter x:Key="VisibilityConverter"/>
</Window.Resources>
....
<Image Visibility="{Binding ArrowDirection, Converter={StaticResource VisibilityConverter}, ConverterParameter=Left}" .../>

ここでArrowDirection、のバインディングパスを指定しますElementInfoCollection[pos].ArrowDirection。が実装されている場合INotifyPropertyChangedは、この値を正しい方向に設定するだけで、可視性が更新されます。

于 2013-03-27T09:26:57.783 に答える