Converter for bound data in style - wpf

Question

Can't see the trees through the forest.
Trying a simple databinding and I want to format the value with a converter. (In this converter example, numeric data that is 0 is not displayed.)
Resource:
<conv:FormattingConverter x:Key="FormattingConverter"/>
<Style x:Key="EGTSTextBoxInt" TargetType="TextBox">
<Setter Property="Background" Value="{StaticResource CC_BACKGROUND}" />
<Setter Property="Foreground" Value="{StaticResource CC_FOREGROUND}" />
<Setter Property="FontFamily" Value="{StaticResource DefaultFont}" />
<Setter Property="FontSize" Value="{StaticResource DefaultFontSize}" />
<Setter Property="FontWeight" Value="Normal" />
<Setter Property="FontStyle" Value="Normal" />
<Setter Property="VerticalContentAlignment" Value="Center" />
<Setter Property="VerticalAlignment" Value="Center"
<Setter Property="HorizontalAlignment" Value="Center" />
<Setter Property="HorizontalContentAlignment" Value="Center" />
<Setter Property="IsReadOnly" Value="True" />
</Style>
Textbox:
<TextBox Name="Bill_Item"
Grid.Column="6"
MinWidth="46"
MinHeight="23"
Style="{StaticResource EGTSTextBoxInt}"
Text="{Binding Path=Item, Mode=TwoWay,
Converter={StaticResource FormattingConverter},
ConverterParameter=\{0:G\}}" />
What I want to do is get the Converter code embedded in the style so that I don't have to spell it out in each Text=line.
Adding code behind the XAML to do anything for this is not an option!
I am looking for a pure XAML method.
I am still trying to grasp how certain things are done in Styles.
Brian

Answer 1

There are several ways to do this.
But before you even start:
It's heavy
It's utterly useless in your case
1) Define a custom markup extension
The idea is to inherit from the Binding markup extension that allows you to write Text ="{Binding SomeProperty}".
You can find an example of someone who made his own binding here
This solution does not allow you to put the feature in a style.
2) Define an attached property
that will modify the Binding of the default property of a control (in your case, Text is the default property of TextBox, as you can do <TextBox>my text</TextBox>) in order to use the converter you want, automatically.
This actually allows you to put set this attached property in a style. It is, however, very bad practice. It's as bad a magic strings.
3)Don't do this, just don't.
Write the converter each time.

Answer 2

The Text property of the TextBox is about data. The Style property is about what that data looks like. It doesn't make sense to attach a Converter to a Style.
Edit: I think I see what you're trying to say now. You want Text="{Binding Path=Item}" in one place and <Setter Property="Text" Value="~somehow get the converter in here and have it applied to the existing text property which is bound to Items~" />
As mydogisbox mentioned, I don't think you can split up these ideas in two places like that.

Answer 3

Converters are for converting one value into another value, so they cannot be used without the value they are converting
You can however use StringFormat in your binding to format values without a Converter
<TextBox Text="{Binding Path=Item, StringFormat=G}" />
You could also create a class that inherits from Binding class and sets the default StringFormat, although I feel this is more trouble than it's worth
<TextBox Text="{local:NumberBinding Path=Item}" />
And if you are ever working with Labels instead of TextBoxes, you can apply a style setter to ContentStringFormat, which will apply formatting to the Label's Content
<Style TargetType="{x:Type Label}">
<Setter Property="ContentStringFormat" Value="G" />
</Style>