How would one achieve mixing bound values with constant text in a WPF bound control?
For example, say I have a form displaying orders, and I want a label that displa
I found another one approach. @Inferis's solution doesn't work for me and @LPCRoy's isn't elegant for me:
<Label Content="{Binding Path=Order.ID, FallbackValue=Placeholder}" ContentStringFormat="Order ID {0}">
It's my favourite at this moment, it's seems flexible and condensed.
If you're using 3.5 SP1, you can use the StringFormat
property on the binding:
<Label Content="{Binding Order.ID, StringFormat=Order ID \{0\}}"/>
Otherwise, use a converter:
<local:StringFormatConverter x:Key="StringFormatter" StringFormat="Order ID {0}" />
<Label Content="{Binding Order.ID, Converter=StringFormatter}"/>
With StringFormatConverter
being an IValueConverter
:
[ValueConversion(typeof(object), typeof(string))]
public class StringFormatConverter : IValueConverter
{
public string StringFormat { get; set; }
public object Convert(object value, Type targetType,
object parameter, CultureInfo culture) {
if (string.IsNullOrEmpty(StringFormat)) return "";
return string.Format(StringFormat, value);
}
public object ConvertBack(object value, Type targetType,
object parameter, CultureInfo culture)
{
throw new NotSupportedException();
}
That'll do the trick.
[Edit : Change the Text
property to Content
]
Modified Mikolaj's answer.
<Label Content="{Binding Order.ID}" ContentStringFormat="Order ID {0}" />
FallbackValue is not a must.
Often overlooked is simply chaining multiple textblocks together for example
<TextBlock Text="{Binding FirstName}" />
<TextBlock Text=" " />
<TextBlock Text="{Binding LastName}" />
The Binding.StringFormat property doesn't work on Labels, you need to use the ContentStringFormat property on the Label.
For example, the following sample will work:
<Label>
<Label.Content>
<Binding Path="QuestionnaireName"/>
</Label.Content>
<Label.ContentStringFormat>
Thank you for taking the {0} questionnaire
</Label.ContentStringFormat>
</Label>
The same as short Version:
<Label Content="{Binding QuestionnaireName}" ContentStringFormat="Thank you for taking the {0} questionnaire" />
Using it to display a unit after the value:
<Label Content="{Binding Temperature}" ContentStringFormat="{}{0}°C" />
While this sample will not:
<Label>
<Label.Content>
<Binding Path="QuestionnaireName" StringFormat="Thank you for taking the {0} questionnaire"/>
</Label.Content>
</Label>
Another approach is to use a single TextBlock with multiple Run elements within it:
<TextBlock><Run>Hello</Run><Run>World</Run></TextBlock>
.. but to bind to a element you need to use add a BindableRun class.
Update But there are some drawbacks to this technique ... see here