Tag Archive : Xamarin

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Xamarin has a long story of problematic releases where new features comes along with numerous bugs.For this reason is possible that you are still using an old version of Xamarin.Forms.But today you will see why you should really upgrade to Xamarin.Forms 2.5

Layout Compression

Sometimes to create the UI we want, we need to add several layouts that are not visible but are needed as container for other components.As you can imagine, all these layouts come with a cost and you can see it especially on older Android devices.Layout compression helps us to solve this problem reducing the number of views to render.Consider this basic example:

<StackLayout Orientation="Horizontal"                  
                 HorizontalOptions="CenterAndExpand"                  
                 VerticalOptions="CenterAndExpand">
        <Button Text="Yes"></Button>
        <Button Text="No"></Button>
    </StackLayout>

We have a StackLayout that contains two buttons, the only reason to have this layout is to add the two buttons at the same height.Even if we don’t see the layout, having it in our Page has a cost.With the Layout Compression we can keep the StackLayout and remove its cost.To enable the compression of the StackLayout we need to add the codeCompressedLayout.IsHeadless="true"so the previous example will be:

<StackLayout Orientation="Horizontal"                  
                 HorizontalOptions="CenterAndExpand"                  
                 VerticalOptions="CenterAndExpand"                 
                 CompressedLayout.IsHeadless="true">
        <Button Text="Yes"></Button>
        <Button Text="No"></Button>
    </StackLayout>

Easy. Isn’t it? You can enable the Layout compression on: StackLayout, AbsoluteLayout, Grid, RelativeLayout.Because the compression removes the renderer for the layout, candidates for the compression are layouts that don’t have:

  • Background color
  • Gestures
  • Transformations
  • etc.

Layout Compression is available on iOS and Android.

Fast Renderers

Ok this is not entirely a new feature (they arrived on Xamarin.Forms 2.4) but it’s definitely a feature you shouldn’t miss.We love Xamarin but we also know that sometimes, especially on Android the performances are not really amazing.Fast Renderers for Android will improve performances on your Xamarin.Forms applications.As this is still an experimental feature, to enable them you need to add this line

Forms.SetFlags("FastRenderers_Experimental");

to your MainActivity class before calling Forms.Init

I’ve personally tested Layout compression and Fast Renderers and I can confirm that there is a performance improvement especially on older Android devices so I really suggest you to use these features in your projects.

Forms Embedding

I have to tell you, I’m not particularly inclined to mix things so I prefer to keep separated Xamarin.Forms and native Xamarin projects.BUT…I can honestly see cases where you already have existing Xamarin.Forms pages and you want to use in other Xamarin iOS, Android or UWP projects.Thanks to the Forms Embedding now you can do it.

Improved macOS Desktop Support

In case you want to add macOS desktop support in your Xamarin.Forms apps 🙂

Android SDK Setup with Xamarin

May 4, 2019 | Guide | No Comments

As you know is very important to keep your system updated and this of course is valid for the Android SDK.You should alway use the lasted available Android components.The Official Xamarin Documentation is not very clear on how to configure properly the Android SDK, so here is what you should do to obtain the best from your Xamarin.Android projects.First of all you should really install the Xamarin Android SDK Manager instead of the classic SDK Manager.Probably the most important reason to do so is that since version 25.2.3 of the Android SDK Tools package, Google replaced the UI Manager with a command line utility. I really don’t know why, but I know that the Xamarin Android SDK Manager is a very good tool. So I really suggest you to download it.As stated in the official Xamarin website, the requirements are:

  • Visual Studio 2017 community edition or higher. Visual Studio 2017 version 15.5 or later is required. (I’ll suggest you to use the latest version 15.6)
  • Xamarin for Visual Studio version 4.5.0 or later.
  • Java Development Kit 8 (the JDK 9 is not supported yet inXamarin.Android)

The Xamarin Android SDK Manager is not compatible with Visual Studio 2015. You can add the Xamarin SDK Manager using the Visual Studio Installer: 

Visual Studio Installer
Install the Xamarin SDK Manager

Be sure to select the Xamarin SDK Manager and install it.If you launch again Visual Studio 2017 and click on Tools > Android > Android SDK Manager, the Xamarin Android SDK Manager will be launched instead of the Google Android SDK Manager.

Android sdk manager
Xamarin SDK Manager

Here there are two tabs: Platforms and Tools.

Platforms

Inside the first Tab you can download and install the platforms you want to support. You don’t need to install all the platforms, you just need to install the most recent one and the lowest that you still want to support.So if you want to support the platforms from Android 4.1, just install the Android SDK Platform 16 (Android 4.1) and the Android SDK Platform 16 (Android Oreo 8.1).

Tools

From the Tools Tab, you should always try to update the tools to the latest version:

Android Tools
Use always the latest available tools

So you should install:

  • Android SDK Tools 26.1.1
  • Android SDK Platform-Tools 27.0.1
  • Android SDK Build-Tools 27.0.3

I also suggest you to install the Android emulator is case you want to try your app on multiple devices. The latest available version is:

  • Android Emulator 27.1.12

I’ll update this guide every time there will be an updated component so I suggest to bookmark/follow this page.

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