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MultiBinding.Converter-Eigenschaft

Gets or sets the converter to use to convert the source values to or from the target value.

Namespace: System.Windows.Data
Assembly: PresentationFramework (in presentationframework.dll)
XML-Namespaces:  http://schemas.microsoft.com/winfx/2006/xaml/presentation

public IMultiValueConverter Converter { get; set; }
/** @property */
public IMultiValueConverter get_Converter ()

/** @property */
public void set_Converter (IMultiValueConverter value)

public function get Converter () : IMultiValueConverter

public function set Converter (value : IMultiValueConverter)

<object Converter="myConverter"/>
 myConverter  A resource reference to a class that implements the IMultiValueConverter interface, which includes implementations of the Convert and ConvertBack methods. To refer to a value converter, use the StaticResource markup extension. 

Eigenschaftenwert

A value of type IMultiValueConverter that indicates the converter to use. The default value is NULL-Verweis (Nothing in Visual Basic).

Individual bindings in the collection can have their own value Converter. For more information, see IValueConverter.

MultiBinding allows you to bind a binding target property to a list of source properties and then apply logic to produce a value with the given inputs. This example demonstrates how to use MultiBinding.

In the following example, NameListData refers to a collection of PersonName objects, which are objects that contain two properties, firstName and lastName. The following example produces a TextBlock that shows the first and last names of a person with the last name first.

<Window
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  xmlns:c="clr-namespace:SDKSample"
  x:Class="SDKSample.Window1"
  Width="400"
  Height="280"
  Title="MultiBinding Sample">
	
  <Window.Resources>
    <c:NameList x:Key="NameListData"/>
    <c:NameConverter x:Key="myNameConverter"/>
...

  </Window.Resources>
...

    <TextBlock Name="textBox2" DataContext="{StaticResource NameListData}">
      <TextBlock.Text>
        <MultiBinding Converter="{StaticResource myNameConverter}"
                      ConverterParameter="FormatLastFirst">
          <Binding Path="FirstName"/>
          <Binding Path="LastName"/>
        </MultiBinding>
      </TextBlock.Text>
    </TextBlock>
...

</Window>

To understand how the last-name-first format is produced, let's take a look at the implementation of the NameConverter:

public class NameConverter : IMultiValueConverter
{
    public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
    {
        string name;

        switch ((string)parameter)
        {
            case "FormatLastFirst":
                name = values[1] + ", " + values[0];
                break;
            case "FormatNormal":
            default:
                name = values[0] + " " + values[1];
                break;
        }

        return name;
    }

    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
    {
        string[] splitValues = ((string)value).Split(' ');
        return splitValues;
    }
}

NameConverter implements the IMultiValueConverter interface. NameConverter takes the values from the individual bindings and stores them in the values object array. The order in which the Binding elements appear under the MultiBinding element is the order in which those values are stored in the array. The value of the ConverterParameter attribute is referenced by the parameter argument of the Converter method, which performs a switch on the parameter to determine how to format the name.

For the complete sample, see Implementing Parameterized MultiBinding Sample.

For another example of an IMultiValueConverter implementation, see Data Binding Demo.

Microsoft .NET Framework 3.0 wird unter Windows Vista, Microsoft Windows XP SP2 und Windows Server 2003 SP1 unterstützt.

.NET Framework

Unterstützt in: 3.0
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