multibinding and WPF

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C#

Visual-Studio

XAML

WPF

Hello,

using visual studio c# 2010 and WPF, I have a TextBox that will be either set by a method exposed as an ObjectDataProvider, or manually set by the end user.
Moreover, this value will be used as an input for another method exposed as another ObjectDataProvider.

I have implemented this kind of behavior on different components, but I have trouble combining everything together.

my method looks like this:

<ObjectDataProvider x:Key="UISpotProvider" ObjectType="{x:Type uilayercommon:UISpotProvider}"/>
        <ObjectDataProvider x:Key="Spot"
          ObjectInstance="{StaticResource UISpotProvider}"
          MethodName="getSpot">
            <ObjectDataProvider.MethodParameters>
                <system:String>Parameter1</system:String>
                <system:DateTime>2011-12-12</system:DateTime>
                <system:String>EUR/USD</system:String>
            </ObjectDataProvider.MethodParameters>
        </ObjectDataProvider>

it returns an object of type UISpot whose member String MID I wish to display in my TextBox.

which I was doing this way:

<TextBox Name="textBoxSpot" DataContext="{Binding Source={StaticResource Spot}}" Text="{Binding Path=MID}" >

this works fine.

now what I want to do, is to use the value in my textbox "textBoxSpot", which may have been overwritten by the end user, as an input to various methods or component.
I did that in another component using the MultiBinding, and I got something like this:

<MultiBinding Converter="{StaticResource CcyPairMultiConverter}" Mode="OneWayToSource">
    <Binding ElementName="comboBoxInstrument" Path="SelectedItem" Mode="OneWayToSource" />
    <Binding Source="{StaticResource Spot}" Path="MethodParameters[2]" BindsDirectlyToSource="True" Mode="OneWayToSource" />
    <Binding Source="{StaticResource PriceUnit}" Path="MethodParameters[0]" BindsDirectlyToSource="True" Mode="OneWayToSource" />

which is working fine too.

So I tried the same thing with my TextBox, many ways without success, and finaly it looks like this:

<TextBox.Text>
   <MultiBinding Converter="{StaticResource SpotMultiConverter}">
         <Binding Source="{StaticResource Spot}" Mode="OneWay"  />
         <Binding ElementName="textBoxSpot" Path="Text" Mode="OneWayToSource" />
   </MultiBinding>
</TextBox.Text>

The SpotMultiConverter looks like this:

public class UISpotMultiConverter : IMultiValueConverter
    {

        #region IMultiValueConverter Members

        public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            //return values[0];
            return ((UISpot)values[0]).MID;
            //throw new NotImplementedException("implement me UICurrencyPairConfigurationMultiConverter.Convert");
        }

        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
        {
            if (value == null)
            {
                return new object[] { };

            }
            return new object[]
            {
                value,
            };

When I set the textbox manually, I see the value going through the ConvertBack, and when it is set via the Spot provider, I see the UISpot in value[0] but I just can get to display it in the textbox. I tried returning it as a String, as an Object, using Path. At this point I don't know what to do.

Any help would be much appreciated,

Cheers!