c# - 将值传递给 IValueConverter

Question

我有一个 ListView，它有一个包含两列和许多行的 Grid。每行在每一列中都有一个 TextBlock，每个 Text 属性都绑定(bind)到 ListView 的 ItemSource 中的一个值。我需要根据第一个 TextBlock 中的值对第二个 TextBlock 中的文本进行一些转换。如何将第一个文本框的值提供给转换器？

这是我目前所拥有的:

XAML:

<UserControl.Resources>
    <local:ValueStringConverter x:Key="valueStringConverter" />
</UserControl.Resources>

<ListView Name="theListView" ItemsSource="{Binding ItemCollection}" SelectedItem="{Binding SelectedItem}" ScrollViewer.HorizontalScrollBarVisibility="Disabled" Grid.Row="1" >
    <ListView.ItemTemplate>
        <DataTemplate>
            <Grid>
                <Grid.RowDefinitions>
                    <RowDefinition Height="Auto" />
                </Grid.RowDefinitions>

                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="Auto" />
                    <ColumnDefinition Width="*" />
                </Grid.ColumnDefinitions>

                <TextBlock Text="{Binding Path=Key}" Grid.Column="0" Margin="0,0,10,0" />
                <TextBlock Text="{Binding Path=Value, Converter={StaticResource valueStringConverter}}" TextWrapping="Wrap" Grid.Column="1" />
            </Grid>
        </DataTemplate>
    </ListView.ItemTemplate>
</ListView>

ValueStringConverter代码:

public class ValueStringConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        string name = (string)value;
        name = name.Replace("$$", " ");
        name = name.Replace("*", ", ");
        name = name.Replace("##", ", ");

        return value;
    }

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

Answer 1

您不能将多个值传递给“常规”值转换器。你可以选择 IMultiValueConverter并将绑定(bind)定义为 MultiBinding .

或者您可以创建一个 IValueConverter，它获取 DataContext 中的整个对象，将对象转换为其类型，获取值和键并返回您需要的字符串。

在您的第二个文本 block 上将绑定(bind)定义为

<TextBlock Text="{Binding Converter={StaticResource valueStringConverter}"/>

你的转换器是:

public class ValueStringConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        MyDataContextObjectType obj= (MyDataContextObjectType)value;
        var name= obj.Name;
        var key = obj.Key;
        //here you have both Name and Key, build your string and return it
        //if you don't know the type of object in the DataContext, you could get the Key and Name with reflection
        name = name.Replace("$$", " ");
        name = name.Replace("*", ", ");
        name = name.Replace("##", ", ");

        return value;
    }

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