Tip: WPF 3.0 String.Format
Posted on June 3rd, 2008 by Paul Stovell
One of the upcoming additions in .NET 3.5 SP1 is a StringFormat parameter you can pass along with your bindings. Sacha Barber has an example of how to use it:
<TextBlock
Text="{Binding Path=AccountBalance, StringFormat='You have {0:c} in your bank account.'}"
/>
However, if you can’t install the service pack or you haven’t been able to upgrade to .NET 3.5, don’t fret. Here’s a snippet, albeit with a few more lines of code, to perform the same thing:
<TextBlock>
<TextBlock.Text>
<MultiBinding
ConverterParameter="Hello {0} {1}, you have {2:c} in your account"
Converter="{StaticResource StringFormatConverter}"
>
<Binding Path="FirstName" />
<Binding Path="LastName" />
<Binding Path="AccountBalance" />
</MultiBinding>
</TextBlock.Text>
</TextBlock>
...
class StringFormatConverter : IMultiValueConverter
{
public object Convert(object[] values, ..., object parameter)
{
return string.Format(parameter.ToString(), values);
}
}
Hooray for String.Format :)
Doesn’t it bug you, though, that StringFormatConverter wasn’t included to begin with?
I’m still wondering how two-way databinding works (if at all) with the StringFormat attribute.
@Matt - there are lots of converters - some of them in WPF but marked internal - that I wish they’d included. But I think they made the right trade offs. The WPF team should be focussing on things that are really difficult to do (like binding infrastucture) and letting p&p, developers and third party libraries build the little helpful things on top (not wasting time building data grids :)).
[…] We Don’t Need No String.Format Binding! (Paul Stovell) […]
Haha - I had a rather heated discussion with a colleague from our local user group on the drive home from Code Camp Oz, who suggested that my apps must not be “functional” because I build them without in-place editing in data grids!
[…] (This was inspired by a funny comment left by Matt Hamilton) […]