.NET MAUI Blazor - Best practices for mobile UI

#dotnet #mobile #webdev #css

Both Blazor and .NET MAUI are great and Powerful frameworks. Using .NET MAUI, you can build fully native cross-platform apps and build web apps completely in C# with Blazor.
But when you combine them with the MAUI Blazor template, you need to know that it should feel like a mobile app, not a web page! So, in this article, I will show you some tips and tricks.

Disable selecting content and texts

There is no need to select all texts and contents in your app! So, you can disable it in your CSS with these properties:

*:not(input) {
    user-select: none;
    -webkit-user-select: none;
}

Remove the default tapping effect

Mostly in mobile devices, when you tap on clickable elements like a tag, it shows some effects. In my experience, Android was showing an ugly blue color and in iOS was a gray one. So, give it your own beautiful effect using active selector in CSS and remove the default one with this CSS property:

* {
    -webkit-tap-highlight-color: transparent;
}

Handling Safe areas

Don’t worry it’s not Blazor or MAUI’s fault that your content is in the Status bar or Home bar. You can fix it in CSS like this:

@supports (-webkit-touch-callout: none) {
    body {
        padding-top: env(safe-area-inset-top);
        padding-right: env(safe-area-inset-right);
        padding-bottom: env(safe-area-inset-bottom);
        padding-left: env(safe-area-inset-left);
    }
}

Changing Android default colors

For those who are not familiar with native stuff, you can change the accent color and status bar color of your Android app from YOURPROJECTNAME\Platforms\Android\Resources\values\colors.xml.

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="colorPrimary">#512BD4</color>
    <color name="colorPrimaryDark">#2B0B98</color>
    <color name="colorAccent">#2B0B98</color>
</resources>

Annoying startup background

When you run your app, you see a “Loading…” text with a white background so let’s fix that!
For “Loading…” text you need to remove it from a div tag with app id in your index.html, then access the BlazorWebView’s handler in your MainPage.xaml.cs and change the default background color of the platforms that you need like this:

BlazorWebViewHandler.BlazorWebViewMapper.AppendToMapping("CustomBlazorWebViewMapper", (handler, view) =>
        {
#if WINDOWS
            //Workaround for WinUI splash screen
            if (AppInfo.Current.RequestedTheme == AppTheme.Dark)
            {
                handler.PlatformView.DefaultBackgroundColor = Microsoft.UI.Colors.Black;
            }
#endif

#if IOS || MACCATALYST
            handler.PlatformView.BackgroundColor = UIKit.UIColor.Clear;
            handler.PlatformView.Opaque = false;
#endif

#if ANDROID
            handler.PlatformView.SetBackgroundColor(Android.Graphics.Color.Transparent);
#endif
        });

Annoying scroll animation

Sometimes you don’t want your app's body (mostly iOS) to have animation when the scroll hits the bottom or top of the page, so you can disable it in the BlazorWebView handler we talked about like this:

BlazorWebViewHandler.BlazorWebViewMapper.AppendToMapping("CustomBlazorWebViewMapper", (handler, view) =>
        {
#if IOS || MACCATALYST
            handler.PlatformView.ScrollView.Bounces = false;
#endif

#if ANDROID
            handler.PlatformView.OverScrollMode = Android.Views.OverScrollMode.Never;
#endif
        });

By the way, I already made a sample repo containing all of the code we discussed. You can have it from here.
Also you can read about the second part of this article which is about Desktop UI from here.

Happy coding ;D

Top comments (9)

Saleh Yusefnejad • Jan 29 '23

great job Mohammad jaan 👍

can't you do something about colorizing the code samples?

Mohammad Hossein Rastegarinia • Jan 29 '23 • Edited

Done, Thanks for the suggestion dear Saleh! ❤️

Emmanuel Oluwagbemiga Adebiyi (Smart) • Jan 29 '23

Great post!

Don't you think for the last one, we could just build the Splash Screen with HTML and CSS in the index.html file?

Mohammad Hossein Rastegarinia • Jan 29 '23

Yeah! I had this in my mind few days ago, but what about MAUI Splash Screen?
Can we remove it? or if we want it to be the same as MAUI how do we get the splash size? I mean you may know that MAUI Splash Screen has deferent sizes in each Android device and OS version.