core/release-notes/10.0/preview/preview5/dotnetmaui.md

.NET MAUI in .NET 10 Preview 5 - Release Notes

Here's a summary of what's new in .NET MAUI, .NET for Android, and .NET for iOS, Mac Catalyst, macOS, and tvOS in this preview release:

• .NET MAUI
  • XAML Global Namespaces
  • XAML Implicit Namespaces
  • Intercept web requests
• .NET for Android
• .NET for iOS, Mac Catalyst, macOS, tvOS

.NET MAUI updates in .NET 10:

• What's new in .NET MAUI in .NET 10 documentation.

XAML Global Namespaces

In your projects you can now glob together XML-namespaces into a new global namespace xmlns="http://schemas.microsoft.com/dotnet/maui/global", and use them without prefixes. The .NET MAUI namespace is included already.

By convention the new project template creates a file GlobalXmlns.cs.

[assembly: XmlnsDefinition(
    "http://schemas.microsoft.com/dotnet/maui/global",
    "MyApp.Views")]
[assembly: XmlnsDefinition(
    "http://schemas.microsoft.com/dotnet/maui/global",
    "MyApp.Controls")]
[assembly: XmlnsDefinition(
    "http://schemas.microsoft.com/dotnet/maui/global",
    "MyApp.Converters")]
[assembly: XmlnsDefinition(
    "http://schemas.microsoft.com/dotnet/maui/global",
    "http://schemas.syncfusion.com/maui/toolkit")]

You can then use anything in those namespaces like you do .NET MAUI controls, without prefix.

<ContentPage 
    xmlns="http://schemas.microsoft.com/dotnet/maui/global"
    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
    x:Class="MyApp.MainPage">
    <TagView x:DataType="Tag" />
</ContentPage>

The x namespace cannot be globbed into the global namespace since it's used for parsing.

XAML Implicit Namespaces

You can opt-in to this feature by adding the following to your project file. As of now, turning this on may cause errors to be reported by various XAML tools.

<PropertyGroup>
  <DefineConstants>$(DefineConstants);MauiAllowImplicitXmlnsDeclaration</DefineConstants>
  <EnablePreviewFeatures>true</EnablePreviewFeatures>
</PropertyGroup>

With this change you can also eliminate xmlns and xmlns:x from XAML files.

<ContentPage x:Class="MyApp.MainPage">
    <TagView x:DataType="Tag" />
</ContentPage>

In this usage:

• the default xmlns is the global one
• the x: prefix is added by default
• all xmlns with a XmlnsPrefix are also accessible with their prefix, even if they are included in the global xmlns. These are useful for disambiguating a name. For example, the maui: prefix points to the maui xmlns.
• you still need to use the x: prefix (e.g. x:Class, x:DataType), but you don't have to declare it

Intercept Web Requests

The HybridWebView now allows you to intercept when the browser requests a web resource in order to take action before it executes, such as adding a header to the request. The do this, add a listener to the WebResourceRequested event.

<HybridWebView WebResourceRequested="HybridWebView_WebResourceRequested" />

private void HybridWebView_WebResourceRequested(object sender, HybridWebViewWebResourceRequestedEventArgs e)
{
  // NOTES:
  // * This method MUST be synchronous, as it is called from the WebView's thread.
  // * This method MUST return a response (even if it is not yet complete), otherwise the 
  //   WebView may freeze or return a error response.
  // * The response must be set using the SetResponse method of the event args.

  // Only handle requests for the specific image URL
  if (!e.Uri.ToString().Contains("sample-image.png"))
    return;

  // Prevent the default behavior of the web view
  e.Handled = true;

  // Return the stream or task of stream that contains the content
  // NOTE: the method is NOT awaited, the WebView will continue to load the content
  e.SetResponse(200, "OK", "image/png", GetStreamAsync());
  }

.NET for Android

This release was focused on quality improvements. A detailed list can be found on dotnet/android GitHub releases.

.NET for iOS, Mac Catalyst, macOS, tvOS

This release was focused on quality improvements. A detailed list can be found on dotnet/macios GitHub releases including a list of Known issues.

Contributors

Thank you contributors! ❤️

@Ahamed-Ali, @Dhivya-SF4094, @HarishKumarSF4517, @KarthikRajaKalaimani, @LogishaSelvarajSF4525, @MartyIX, @NafeelaNazhir, @NanthiniMahalingam, @NirmalKumarYuvaraj, @PaulAndersonS, @PureWeen, @Shalini-Ashokan, @StephaneDelcroix, @SubhikshaSf4851, @SuthiYuvaraj, @SyedAbdulAzeemSF4852, @Tamilarasan-Paranthaman, @TamilarasanSF4853, @Vignesh-SF3580, @anandhan-rajagopal, @bhavanesh2001, @corvinsz, @devanathan-vaithiyanathan, @drasticactions, @jfversluis, @jonathanpeppers, @jsuarezruiz, @kubaflo, @mattleibow, @moljac, @nivetha-nagalingam, @pjcollins, @prakashKannanSf3972, @praveenkumarkarunanithi, @rmarinho, @simonrozsival, @tj-devel709