Jonathan Peppers jonathanpeppers

Over December, I have been able to work on Xamarin.Forms + Android startup perf. Here is the initial results I'm seeing with the accumulation of all my changes.

All runs were on a Pixel 3 XL

16.4 Blank Forms App template, Xamarin.Forms 4.4.0.991265

Debug:

01-15 23:46:01.157  1473  1503 I ActivityTaskManager: Displayed com.xamarin.forms.helloforms/crc6450e568c951913723.MainActivity: +859ms
01-15 23:46:04.919  1473  1503 I ActivityTaskManager: Displayed com.xamarin.forms.helloforms/crc6450e568c951913723.MainActivity: +843ms

How does Java interop work in .NET 6?

Most of this also applies to Xamarin.Android, as we have nearly the same implementation.

Let's start with a simple Android API call:

Android.Util.Log.Debug ("MYTAG", "MyMessage");

.NET Workload Troubleshooting

To install the maui workload, you have two options:

dotnet workload install commands
Visual Studio on Windows can install .msi files for each workload pack. Note that the concept of a "Visual Studio workload" is different than a ".NET workload".

VS for Mac's installer and updater use dotnet workload install commands. It's considerably simpler to get a Mac machine to a clean state.

Mac

VS Windows

Install Project System Tools for VS 2022.

Open View > Other Windows > Build Logging:

Hit the "play" button:

These instructions are also on this MS internal loop.

.NET SDK

For now, use a specific build of the .NET SDK:

How I Work on .NET MAUI

This is a description on how I build/contribute to .NET MAUI, it may differ from DEVELOPMENT.md. I thought I would write this down in case it helps someone.

Building

If I'm testing the provisioning of .NET and workloads, I may run:

Part of the docs are here:

https://github.com/xamarin/xamarin-android/blob/main/Documentation/guides/tracing.md#how-to-get-gc-memory-dumps

But this expands on this, with a list of steps I do to profile .NET MAUI.

An overview:

Build & Run the Device Tests on Catalyst
Attach dotnet-trace with some settings

	[2019-04-10T12:29:41.127Z] _GenerateJniMarshalMethods:
	[2019-04-10T12:29:41.127Z] MONO_PATH="/Users/builder/jenkins/workspace/xamarin-android-pr-pipeline-release/xamarin-android/bin/Release/lib/xamarin.android/xbuild-frameworks/MonoAndroid/v1.0/:obj/Release/linksrc/" "/Users/builder/jenkins/workspace/xamarin-android-pr-pipeline-release/xamarin-android/bin/Release/lib/xamarin.android/xbuild/Xamarin/Android/Darwin//mono" --debug "/Users/builder/jenkins/workspace/xamarin-android-pr-pipeline-release/xamarin-android/bin/Release/lib/xamarin.android/xbuild/Xamarin/Android/jnimarshalmethod-gen.exe" --jvm="/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/jre/lib/jli/libjli.dylib" "obj/Release/linksrc/Mono.Android-Tests.dll" "obj/Release/linksrc/Mono.Android_Test.Library.dll" "obj/Release/linksrc/TestRunner.Core.dll" "obj/Release/linksrc/TestRunner.NUnit.dll" "obj/Release/linksrc/Mono.Android.dll" "obj/Release/linksrc/Xamarin.Android.NUnitLite.dll"
	[2019-04-10T12:29:41.424Z]
	[2019-04-10T12:29:41.4

	SRC_DIR="/Users/jopepper/src"
	XA_DIR="$SRC_DIR/xamarin-android"
	XA_TOOLCHAIN_DIR="/Users/jopepper/android-toolchain"
	XA_ANDROID_SDK_DIR="$XA_TOOLCHAIN_DIR/sdk"
	JAVA_HOME="$XA_TOOLCHAIN_DIR/jdk"
	alias xabuild="$XA_DIR/bin/Debug/bin/xabuild"
	alias xabuildr="$XA_DIR/bin/Release/bin/xabuild"
	alias adb="$XA_ANDROID_SDK_DIR/platform-tools/adb"
	alias java="$JAVA_HOME/bin/java"
	alias javac="$JAVA_HOME/bin/javac"

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	"alwaysShowTabs" : true,
	"defaultProfile" : "{61c54bbd-c2c6-5271-96e7-009a87ff44bf}",
	"initialCols" : 120,
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