Scrolling Issue on Tabbed Page in iOS When Adding Dynamic Labels

Hello,

iOS may not recalculate the layout properly after dynamic changes, especially when the UI thread is briefly idle or the layout pass is skipped.

To resolve this, please try forcing a layout refresh after adding each label. This ensures the scroll view recalculates its content size properly.

Steps to implement:

1. Modify your OnAddLabelTab1 and OnAddLabelTab2 methods to include layout refresh logic.
2. Use Device.BeginInvokeOnMainThread to ensure UI updates occur on the main thread.

public partial class TabbedPageDemo : TabbedPage
{
    public TabbedPageDemo()
    {
        InitializeComponent();
    }
 
    private int labelCounterTab1 = 10;
    private int labelCounterTab2 = 10;
 
    private void OnAddLabelTab1(object sender, EventArgs e)
    {
        Tab1Stack.Children.Add(new Label { Text = $"New Label {labelCounterTab1} in Tab 1", FontSize = 20 });
        labelCounterTab1++;
 
        Device.BeginInvokeOnMainThread(() =>
        {
            Tab1Stack.ForceLayout();
            Tab1Scroll.ForceLayout(); // Ensure you name your ScrollView as Tab1Scroll in XAML
        });
    }
 
    private void OnAddLabelTab2(object sender, EventArgs e)
    {
        Tab2Stack.Children.Add(new Label { Text = $"New Label {labelCounterTab2} in Tab 2", FontSize = 20 });
        labelCounterTab2++;
 
        Device.BeginInvokeOnMainThread(() =>
        {
            Tab2Stack.ForceLayout();
            Tab2Scroll.ForceLayout(); // Ensure you name your ScrollView as Tab2Scroll in XAML
        });
    }
}

If the issue persists, consider adding a short delay before forcing layout:

  await Task.Delay(50);

I hope this helps resolve the issue.

References:

• ScrollView Documentation
• Keep subview aligned to top on .NET MAUI ScrollView [iOS issue]