String Formatting in WPF Using C#

Here’s a comprehensive post on String Formatting in WPF (Windows Presentation Foundation) using C#. This article is suitable for developers who want to understand how to properly format strings in WPF UI elements like TextBlock, Label, TextBox, and within bindings.

String Formatting in WPF Using C#

Getting Started

String formatting is a fundamental part of displaying data in a user-friendly way. In WPF (Windows Presentation Foundation), C# provides several mechanisms to format strings, whether you're binding data to UI elements or displaying calculated values.

This article covers:

Basic string formatting with String.Format()
String formatting in XAML data bindings
Using StringFormat in Binding
Custom format strings
Culture-aware formatting

Basic C# Format String Example

In regular C# code (e.g., code-behind or view model), the most common way to format strings is with String.Format() or string interpolation.

int age = 20;
string name = "Raghav";
string message = String.Format("Name: {0}, Age: {1}", name, age);
// OR using string interpolation
string message2 = $"Name: {name}, Age: {age}";
Console.WriteLine(message2);

Output

 Name: Raghav, Age: 20

These methods are often used in the logic layer, but when building UIs with WPF, we typically use bindings and format strings directly in XAML.

String Formatting in WPF XAML Bindings

WPF uses data binding to connect UI elements to data sources. You can format these bound values using the StringFormat property in XAML.

Basic String Format Example

<TextBlock Text="{Binding Price, StringFormat='Price: {0:C}'}" />

In this example:

Price is a numeric property from the data context.
{0:C} formats it as currency based on the current culture.

Syntax Tip: Make sure you use single quotes (') around the format string if it contains curly braces in XAML.

Common Format Strings in WPF

Format	Description	Example
`{0:C}`	Currency	`$10.00`
`{0:P}`	Percent	`90%`
`{0:N2}`	Number with 2 decimals	`1,234.57`
`{0:D}`	Long date	`Sunday, October 12, 2025`
`{0:MM/dd/yyyy}`	Custom date	`10/12/2025`

Formatting Dates in WPF

<TextBlock Text="{Binding CreatedDate, StringFormat='Created on: {0:MMMM dd, yyyy}'}" />

Output

Created on: October 12, 2025

Culture-Aware Formatting

WPF respects the culture settings of the current thread or application. This is especially useful for formatting dates, currency, and numbers.

You can explicitly set the culture in App.xaml.cs:

CultureInfo culture = new CultureInfo("en-US");
Thread.CurrentThread.CurrentCulture = culture;
Thread.CurrentThread.CurrentUICulture = culture;

Or you can use a Binding.ConverterCulture in XAML:

<TextBlock Text="{Binding Price, StringFormat='Price: {0:C}', ConverterCulture='fr-FR'}" />

Formatting Multiple Bindings with MultiBinding

If you want to format multiple bound properties, use a MultiBinding and a StringFormat.

<TextBlock>
<TextBlock.Text>
<MultiBinding StringFormat="Name: {0}, Age: {1}">
<Binding Path="Name"/>
<Binding Path="Age"/>
</MultiBinding>
</TextBlock.Text>
</TextBlock>

Format in Code-Behind

If you need to apply formatting dynamically:

Binding binding = new Binding("Price")
 {
   StringFormat = "Price: {0:C}"
  };
  textBlock.SetBinding(TextBlock.TextProperty, binding);

Tips:

Use StringFormat inside bindings to avoid extra code.
Handle culture with ConverterCulture or global settings.
Use MultiBinding for complex string compositions.

Summary

String formatting in WPF is powerful and flexible. Whether you're showing prices, dates, or complex messages, using StringFormat in XAML keeps your UI clean and responsive to culture and localization.

Thanks

String Formatting in WPF Using C#