XAML Just Leveled Up: Say Goodbye to Converters in .NET MAUI

🔥 XAML Just Leveled Up: Say Goodbye to Converters in .NET MAUI

The most important change to XAML in over a decade is here — and it completely transforms how we build UI in .NET MAUI.

For years, writing UI logic in XAML felt… constrained. Need to invert a boolean?
Write a converter. Need to combine properties into a formatted string?
Write a converter. Need to calculate price * quantity?
Yep — another converter. It worked.
But it was noisy.
Verbose.
And frankly… outdated. That era is officially over.

🚀 C# Expressions Are Now Native in XAML (.NET 10)

.NET MAUI is introducing inline C# expressions directly inside XAML bindings — compiled, source-generated, and high-performance. This isn’t syntactic sugar. This is architectural evolution.

🧠 What This Actually Means

You can now write:

• Boolean negation
• String interpolation
• Arithmetic calculations
• Inline formatting
• Conditional logic

All directly in XAML. And because it’s powered by XAML source generation, everything compiles to C#. No runtime reflection.
No converter overhead.
No extra classes.
No binding gymnastics.

🛑 Before: The Converter Era

<Button
    IsEnabled="{Binding IsBusy, Converter={StaticResource InvertBoolConverter}}" />

public class InvertBoolConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        => !(bool)value;
}

We wrote entire classes just to flip a boolean.

✅ Now: Just Use !

<Button
    IsEnabled="{Binding !IsBusy}" />

That’s it. No converter.
No resource.
No ceremony.

💰 Calculations Without Backing Properties

Before:

public decimal Total => Price * Quantity;

Now:

<Label Text="{Binding Price * Quantity}" />

Inline.
Readable.
Self-contained.

🧾 String Interpolation Directly in XAML

Before:

public string DisplayPrice => $"${Price:0.00}";

Now:

<Label Text="{Binding $"${Price:0.00}"}" />

Yes — real C# interpolation.

🧩 From MultiBindings to Single Lines

Previously, combining values meant MultiBinding + converter. Now:

<Label Text="{Binding $"{FirstName} {LastName}"}" />

Clean.
Modern.
Expressive.

⚡ Performance: This Is Not Just Developer Candy

Here’s the part most people are missing. These expressions are part of:

🏗 XAML Source Generation

Which means:

• Compiled to C#
• No runtime parsing
• No reflection
• No converter invocation
• No dynamic evaluation

Microsoft has hinted at massive gains because this eliminates binding indirection and reflection-heavy logic. In complex UIs, this compounds fast.

🧪 What’s Technically Happening?

Instead of treating bindings as strings evaluated at runtime, the new compiler:

1. Parses expressions at build time
2. Generates strongly-typed C# code
3. Integrates directly into compiled bindings

This is the same philosophy that gave us:

• Compiled bindings
• AOT-friendly MAUI apps
• Performance improvements across .NET

Now XAML joins that evolution.

📅 Timeline Update

Originally planned for .NET 11,
these features are now arriving in .NET 10. That’s sooner than expected. And it signals something bigger: XAML is not legacy.
It’s evolving.

🛠 Developer Productivity Gains

Less code.
Less friction.
More velocity.

🎯 Why This Is a Game-Changer for .NET MAUI

This isn’t about syntax. It’s about:

• 🧹 Removing boilerplate
• 🚀 Improving performance
• 🧠 Making XAML expressive again
• 📉 Reducing architectural clutter
• 🔍 Making UI logic transparent

And for teams maintaining large MAUI apps? This is enormous.

👑 Full Credit

All credit for the detailed explanation and demonstrations of these new XAML C# expressions goes to Gerald Versluis, member of the .NET MAUI team. His breakdown of the feature showcases just how powerful this shift really is.