maui-scrolling-performance

Test repository for measuring scrolling performance of .NET MAUI apps on Android.

Measuring scrolling peformance on Android is a bit tricky. The Android docs describe a FrameMetricsAggregator class we can use to measure frame times or as Google calls it, "jank".

We can use this to measure the scrolling performance of .NET MAUI apps.

For iOS, we can use CADisplayLink to measure the frame times, such as the example on:

• https://thisiskyle.me/posts/measuring-ios-scroll-performance-is-tough-use-this-to-make-it-simple-and-automated.html

How to Setup?

iOS or MacCatalyst

In either Platforms/MacCatalyst/AppDelegate.cs or Platforms/iOS/AppDelegate.cs:

public override bool FinishedLaunching(UIApplication application, NSDictionary launchOptions)
{
    var result = base.FinishedLaunching(application, launchOptions);
    iOS.FrameMetrics.FrameMetricsReporter.Initialize();
    return result;
}

This uses CADisplayLink to measure how fast the display can refresh.

Run the app and scroll around a bit. You can see output such as:

2024-05-01 14:34:50.404623-0500 CvSlowJittering[98066:9539784] Frames dropped: 38
2024-05-01 14:34:50.404726-0500 CvSlowJittering[98066:9539784] Cumulative frames dropped: 76
2024-05-01 14:34:50.404787-0500 CvSlowJittering[98066:9539784] -----
2024-05-01 14:34:50.955571-0500 CvSlowJittering[98066:9539784] Frames dropped: 32
2024-05-01 14:34:50.955675-0500 CvSlowJittering[98066:9539784] Cumulative frames dropped: 108
2024-05-01 14:34:50.955729-0500 CvSlowJittering[98066:9539784] -----
2024-05-01 14:34:51.149430-0500 CvSlowJittering[98066:9539784] Frames dropped: 6
2024-05-01 14:34:51.149549-0500 CvSlowJittering[98066:9539784] Cumulative frames dropped: 114
2024-05-01 14:34:51.149626-0500 CvSlowJittering[98066:9539784] -----

I haven't written a script to capture this data yet, so you'll have to do this manually for now. A CollectionView with a single Label will drop very few frames, while the examples in external will drop many frames.

Android

In Platforms/Android/MainActivity.cs:

protected override void OnCreate(Bundle savedInstanceState)
{
    base.OnCreate(savedInstanceState);
    Android.FrameMetrics.FrameMetricsReporter.Initialize(this);
}

Build & run your app in Release mode:

dotnet build -c Release -t:Run

Find out the name of the current activity:

> adb shell 'dumpsys window | grep mCurrentFocus'
  mCurrentFocus=Window{f01fc52 u0 com.companyname.surfingapp/crc6435627e4593d70ff9.MainActivity}

Run the script:

.\scripts\scroll-performance.ps1 -package com.companyname.surfingapp -activity crc6435627e4593d70ff9.MainActivity
...
05-08 14:55:47.347 31085 31085 I DOTNET  : Frame(s) that took ~9ms, count: 2
05-08 14:55:47.348 31085 31085 I DOTNET  : Frame(s) that took ~10ms, count: 6
05-08 14:55:47.348 31085 31085 I DOTNET  : Frame(s) that took ~11ms, count: 20
05-08 14:55:47.348 31085 31085 I DOTNET  : Frame(s) that took ~12ms, count: 2
05-08 14:55:47.348 31085 31085 I DOTNET  : Frame(s) that took ~15ms, count: 1
05-08 14:55:47.348 31085 31085 I DOTNET  : Frame(s) that took ~16ms, count: 1
05-08 14:55:47.348 31085 31085 I DOTNET  : Frame(s) that took ~19ms, count: 1
05-08 14:55:47.367 31085 31085 I DOTNET  : Frame(s) that took ~22ms, count: 17
05-08 14:55:47.367 31085 31085 I DOTNET  : Frame(s) that took ~23ms, count: 4
05-08 14:55:47.368 31085 31085 I DOTNET  : Average frame time: 15.52ms
05-08 14:55:47.368 31085 31085 I DOTNET  : No. of slow frames: 23
05-08 14:55:47.368 31085 31085 I DOTNET  : -----

This scrolls this app a few times and prints out the average frame time and the number of frames that took longer than 16ms (60fps).

Results

Installed software:

.NET SDK 9.0.101

Installed Workload Id      Manifest Version       Installation Source
---------------------------------------------------------------------
android                    35.0.7/9.0.100         VS 17.12.35527.113
ios                        18.1.9163/9.0.100      VS 17.12.35527.113
maccatalyst                18.1.9163/9.0.100      VS 17.12.35527.113
maui-windows               9.0.0/9.0.100          VS 17.12.35527.113

.NET version	Sample	Device	Average Frame (ms)	Slow Frames
.NET 8	cvslow	Pixel 7 Pro	6.90ms	10
.NET 9	cvslow	Pixel 7 Pro	5.99ms	4
.NET 8	surfing	Pixel 7 Pro	7.39ms	14
.NET 9	surfing	Pixel 7 Pro	8.22ms	18
.NET 8	gallery	Pixel 7 Pro	9.20ms	34
.NET 9	gallery	Pixel 7 Pro	8.25ms	25