传递多个绑定值作为绑定 CONVERTER PARAMETER

Question

我需要将两个值（在可能的情况下命名为 Unit 和 Quantity）作为转换器参数传递给绑定转换器。（请注意，我不需要将这些值作为绑定值（多重绑定）传递，我需要将它们作为绑定转换器参数传递，因为我需要转换器的 Convert 和 ConvertBack 方法）。我认为可行的唯一方法是创建一个新的 class UnitQuantityBindClass 以将它们设置为 class 并将此 class 作为转换器传递参数，但此 class 没有获得绑定值，当我通过转换器时，创建的 class 转换器参数没有值。有人可以帮助我吗？

public class UnitQuantityBindClass:DependencyObject
{
    public static readonly DependencyProperty QuantityProperty = DependencyProperty.Register(
        "Quantity", typeof(EQuantities), typeof(UnitQuantityBindClass));

    public EQuantities Quantity
    {
        get { return (EQuantities)GetValue(QuantityProperty); }
        set { SetValue(QuantityProperty, value); }
    }

    public static readonly DependencyProperty UnitProperty = DependencyProperty.Register(
        "Unit", typeof(Enum), typeof(UnitQuantityBindClass));

    public Enum Unit
    {
        get { return (Enum)GetValue(UnitProperty); }
        set { SetValue(UnitProperty, value); }
    }
}

用法：

<textboxunitconvertor:TextBoxUnitConvertor Name="gasDensityValueControl" InstantaneousConvert="True" Margin="96,163,0,0" IsEnabled="{Binding ElementName=chkGas,Path=IsChecked}" QuantityBind="{Binding _FluidBlackOilClass.SGGas_SC.Quantity , RelativeSource={RelativeSource AncestorType=Window}, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}"  Width="206" Height="28" HorizontalAlignment="Left" VerticalAlignment="Top">
    <textboxunitconvertor:TextBoxUnitConvertor.TextBoxText>
        <Binding Path="_FluidBlackOilClass.SGGas_SC.Value" RelativeSource="{RelativeSource AncestorType=Window}" UpdateSourceTrigger="PropertyChanged" Mode="TwoWay" Converter="{StaticResource ValueStorageForUnitConverter}">
             <Binding.ConverterParameter>
                 <classes:UnitQuantityBindClass
                     Quantity="{Binding ElementName=gasDensityValueControl,
                                Converter={StaticResource DummyConverter},
                                Path=_Quantity,
                                UpdateSourceTrigger=PropertyChanged,
                                Mode=TwoWay,
                                PresentationTraceSources.TraceLevel=High}"
                     Unit="{Binding ElementName=gasDensityValueControl,
                            Path=_CurrentUnitEnum,
                            UpdateSourceTrigger=PropertyChanged,
                            Mode=TwoWay}" />
             </Binding.ConverterParameter>
        </Binding>
    </textboxunitconvertor:TextBoxUnitConvertor.TextBoxText>
</textboxunitconvertor:TextBoxUnitConvertor>

注意：我的要求是获取“_FluidBlackOilClass.SGGas_SC.Value”并将其传递给转换器，我还需要传递“_Quantity”和“_CurrentUnitEnum”作为转换器参数以转换“_FluidBlackOilClass.SGGas_SC.Value”根据“_Quantity”和“_CurrentUnitEnum”设置一个新值并将其设置为TextBoxText。我还需要根据“_Quantity”和“_CurrentUnitEnum”转换回 TextBoxText 以存储在“_FluidBlackOilClass.SGGas_SC.Value”中。

Answer 1

让你的 Converter 继承 Freezable，并引入一个名为 SourceTextBox 的 DP，它将获取对你的 TextBox 的引用，然后在你的 Convert 和 ConvertBack 方法，您可以使用此引用来获取所需的属性。

public class BindableConverter : Freezable, IValueConverter
{
    #region Overrides of Freezable    
    protected override Freezable CreateInstanceCore()
    {
        return new BindableConverter();
    }    
    #endregion       

    public TextBox SourceTextBox
    {
        get { return (TextBox)GetValue(SourceTextBoxProperty); }
        set { SetValue(SourceTextBoxProperty, value); }
    }

    // Using a DependencyProperty as the backing store for SourceTextBox.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty SourceTextBoxProperty =
        DependencyProperty.Register("SourceTextBox", typeof(TextBox), typeof(BindableConverter), new PropertyMetadata(null));


    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        // ... do something with SourceTextBox here
    }

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        // ... do something
    }
}

用法：

<textboxunitconvertor:TextBoxUnitConvertor Name="gasDensityValueControl" ... >
   <textboxunitconvertor:TextBoxUnitConvertor.Resources>
      <local:BindableConverter x:Key="ValueStorageForUnitConverter" SourceTextBox="{Binding ElementName=gasDensityValueControl}"/>
   </textboxunitconvertor:TextBoxUnitConvertor.Resources>
   ...
</textboxunitconvertor:TextBoxUnitConvertor>

传递多个绑定值作为绑定 CONVERTER PARAMETER

pass multiple binded values as binding CONVERTER PARAMETER

c#

wpf

binding

converter