[WinUI] Creating a complex grid is very slow

[MartyIX]

Description

I have a non-trivial grid which I create by hand (not in XAML but by code) and it can easily take hundreds of milliseconds to show such a grid.

Steps to Reproduce

1. Fetch https://github.com/MartyIX/maui/tree/feature/2024-04-11-grid-perf (MartyIX@dbb147d)
2. cd src/Controls/samples/Controls.Sample.Sandbox
3. dotnet publish -f net8.0-windows10.0.19041.0 -c Release -p:PublishReadyToRun=false -p:WindowsPackageType=None
4. dotnet trace collect --format speedscope -- .\bin\Release\net8.0-windows10.0.19041.0\win10-x64\publish\Maui.Controls.Sample.Sandbox.exe
5. Click "Generate Grid" to generate a 30x30 grid and see how long it took.

It can take 900 ms, and then it speeds up after a several clicks to about 600 ms but it does not drop under that bound.

Speedscope

Maui.Controls.Sample.Sandbox.exe_20240411_223826.speedscope.json

From the data, it's clear that

maui/src/Controls/src/Core/Layout/GridExtensions.cs

Line 60 in 0a562dc

public static void AddWithSpan(this Grid grid, IView view, int row = 0, int column = 0, int rowSpan = 1, int columnSpan = 1)

takes a lot of time but it's very much unclear to me how to speed it up because it seems there is no batching support in MAUI right now.

Link to public reproduction project repository

https://github.com/MartyIX/maui/tree/feature/2024-04-11-grid-perf

Version with bug

8.0.20 SR4

Is this a regression from previous behavior?

Not sure, did not test other versions

Last version that worked well

Unknown/Other

Affected platforms

Windows, I was not able test on other platforms

Affected platform versions

Windows 10, Windows 11

Did you find any workaround?

No.

Relevant log output

No response

[daltzctr]

I reproduced this in release mode with the following code. The root page is just a ContentPage in a blank MAUI project.

private void Button_Clicked(System.Object sender, System.EventArgs e)
{
    List<Label> labels = new List<Label>();

    const int numRows = 30;
    const int numCols = 30;

    Stopwatch watcher = new Stopwatch();

    RowDefinitionCollection rowDefinitions = new RowDefinitionCollection();
    ColumnDefinitionCollection columnDefinitions = new ColumnDefinitionCollection();

    /* Configure sizing */
    for (int i = 0; i < numCols; i++)
    {
        rowDefinitions.Add(new RowDefinition(50));
        columnDefinitions.Add(new ColumnDefinition(50));
    }

    /* Add labels */
    for (int i = 0; i < numCols; i++)
    {
        for (int x = 0; x < numRows; x++)
        {
            labels.Add(new Label()
            {
                Text = $"Label {i}:{x}"
            });
        }
    }
    
    content.RowDefinitions = rowDefinitions;
    content.ColumnDefinitions = columnDefinitions;

    int z = 0;
    watcher.Start();
    /* Add content */
    for (int i = 0; i < numCols; i++)
    {
        for (int x = 0; x< numRows; x++)
        {
            content.Add(labels[z], i, x);

            z++;
        }
    }
    watcher.Stop();

    debugTxt.Text = $"Time Taken: {watcher.Elapsed.TotalMilliseconds}ms";
}

[MartyIX]

Master

Avg time to create a grid was: 920 ms

Branch with WindowsBatchPropertyMapper

Avg time to create a grid was: 694 ms (25% improvement)

https://github.com/MartyIX/maui/tree/feature/2024-04-12-grid-perf-full containing two commits

• MartyIX@8b98cfb
• MartyIX@33aa722