傳遞多個綁定值作爲綁定轉換器參數

Question

我需要將兩個值（可能情況下命名爲單位和數量）作爲轉換器參數傳遞給綁定轉換器（請注意，我不需要將這些值作爲綁定值多重綁定），我需要將它們作爲綁定轉換器參數傳遞，因爲我需要轉換器的Convert和ConvertBack方法）。 我認爲這樣做的唯一方法是創建一個新類UnitQuantityBindClass將它們設置在該類中，並將此類作爲轉換器參數傳遞，但此類不會獲得綁定值，當我通過轉換器時，轉換器參數是創建的類，不具有值。 能幫我一個嗎？

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：我的要求是獲得「_FluidBlackOilClass.SGGas_SC.Value」，並把它傳遞到轉換器，也是我需要通過「_Quantity」和「_CurrentUnitEnum」爲轉換器參數根據「_Quantity」和「_CurrentUnitEnum」將「_FluidBlackOilClass.SGGas_SC.Value」轉換爲新值並將其設置爲TextBoxText。還需要根據「_Quantity」和「_CurrentUnitEnum」將TextBoxText轉換回「_FluidBlackOilClass.SGGas_SC.Value」中。

Answer 1

1. 讓你的轉換器繼承Freezable，並引入DP稱爲SourceTextBox將獲得關於你TextBox，然後在Convert和ConvertBack方法，您可以使用此引用來得到所需的性能。

   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 
       } 
   } 
   

2. 用法：

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