Views don’t default to native attributes

[breyed]

Description

Even though MAUI builds off a long tradition of “build a native UI”, by default its views differ from native platform views. MAUI should not override the platform defaults, but instead let the platform render them natively if not overridden by user code.

For example, when no style or attribute is applied to the color of a Label, Button, or other view, the platform’s native colors are not used. It’s as if something at startup is setting the colors to non-native defaults. The same applies to other attributes such as size and padding.

Internally, the attributes should default to no value, which should tell the handlers not set a value on the platform view. If a getter is called on a property such as color, its value should be read from the native platform.

Steps to Reproduce

1. Create a MAUI app and a SwiftUI app from the dotnet new and Xcode templates.
2. Remove the styles from the MAUI template.
3. Create buttons on each app with blocky text for easy comparison.
4. Run each app and note the differences.

<Button Text="⬛︎⬛︎⬛︎⬛︎⬛︎ Enabled XAML ⬛︎⬛︎⬛︎⬛︎⬛︎⬛︎" />
<Button Text="⬛︎⬛︎⬛︎⬛︎⬛︎ Disabled XAML ⬛︎⬛︎⬛︎⬛︎⬛︎⬛︎" IsEnabled="False" />

Button("⬛︎⬛︎⬛︎⬛︎⬛︎ Enabled SwiftUI ⬛︎⬛︎⬛︎⬛︎⬛︎⬛︎") {}
Button("⬛︎⬛︎⬛︎⬛︎⬛︎ Disabled SwiftUI ⬛︎⬛︎⬛︎⬛︎⬛︎⬛︎") {}.disabled(true)

Tool	Light Enabled	Light Disabled	Dark Enabled	Dark Disabled
XAML	#007AFF	#C4C4C4	#0A84FF	#2E2E2E
SwiftUI	#007AFF	#C5C5C7	#0A84FF	#464649

Link to public reproduction project repository

No response

Version with bug

8.0.40 SR5

Is this a regression from previous behavior?

Yes, this used to work in Xamarin.Forms

Last version that worked well

Unknown/Other

Affected platforms

iOS

Affected platform versions

Tested on iOS 17. Likely affects all platforms and versions.

Did you find any workaround?

You’d could create the styles yourself and then aligned with platform changes, in theory including variants for downlevel native defaults. Alternatively, you could create custom startup code to query the platform’s native defaults and creating styles accordingly.

Relevant log output

No response

[github-actions]

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• Default styling for controls does not work! (#17414), similarity score: 0.73
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[breyed]

This issue is similar to #17414. The other issue lists Windows as the affected platform and gives an example of a Windows corner radius. This issue lists all platforms as likely affected and gives examples of iOS font size and color.

[mattleibow]

Are you able to test with Xcode and Objective C? I think the Swift UI styles are not the default styles but rather the new Swift UI team's implementation of the default styles.

[dotnet-policy-service]

Hi @breyed. We have added the "s/needs-info" label to this issue, which indicates that we have an open question for you before we can take further action. This issue will be closed automatically in 7 days if we do not hear back from you by then - please feel free to re-open it if you come back to this issue after that time.

[breyed]

I created a new app in Xcode using Storyboard (UIKit) for the interface. I added to the storyboard enabled and disabled buttons, leaving all attributes at their defaults. I did this with both Swift and Objective C. Regardless of the language, the colors are identical to the SwiftUI app’s colors.

iOS 13 added support for both dark mode and SwiftUI. With dark mode support, Apple added colors that vary based on light/dark mode. SwiftUI and UIKit both tap into those.

Having thought through that, I changed SupportedOSPlatformVersion in the MAUI app to 13.0. That fixed the problem. The MAUI colors and sizes now match that of XAML. XAML does add some padding around the buttons, but that appears to be intentional to cause buttons to lay out similarly between platforms. Actually, SupportedOSPlatformVersion had no effect. I had forgotten that I had added styling code to my test app to emulate the native color and size.

[drasticactions]

https://github.com/drasticactions/MauiRepros/tree/main/AppleColors

I wrote four test apps: One in SwiftUI, One in Swift/UIKit, One in MAUI, One with .NET iOS directly with no MAUI UI Toolkit. These screenshots were taken with the iPhone 15 Pro simulator.

If you compare the Swift app with Swift UI one, you'll have the same Hex values for the colors. Likewise with Dark mode.

The Swift (Non SwiftUI) colors match up with the XAML values, and the .NET iOS C# ones. Likewise with font sizes. If you want to compare the defaults in UIKit with what's in MAUI, IMO, your best bet is not using SwiftUI to do it.