How can the scrolling direction in a .NET MAUI ListView be detected?

In .NET MAUI ListView, it is possible to detect the scrolling direction. This can be achieved by using the Scrolled event of the ScrollView.
Steps to Detect Scrolling Direction

1. In the SfListView.HeaderTemplate, bind the ViewModel property to display the scroll direction.

XAML

 <syncfusion:sflistview x:name="listView" itemsize="60" isstickyheader="True" itemssource="{Binding ContactsInfo}">
                <syncfusion:sflistview.behaviors>
                    <local:listviewbehavior>
                </local:listviewbehavior></syncfusion:sflistview.behaviors>

                <syncfusion:sflistview.headertemplate>
                    <datatemplate>
                        <label text="{Binding ScrollDirection}" fontsize="Default" fontattributes="Italic" horizontaltextalignment="Center" horizontaloptions="CenterAndExpand" verticaloptions="CenterAndExpand">
                    </label></datatemplate>
                </syncfusion:sflistview.headertemplate>
                <syncfusion:sflistview.itemtemplate>
                    <datatemplate>
                        <grid x:name="grid">
                            <grid.columndefinitions>
                                <columndefinition width="70">
                                <columndefinition width="*">
                            </columndefinition></columndefinition></grid.columndefinitions>
                            <img source="{Binding ContactImage}" verticaloptions="Center" horizontaloptions="Center" heightrequest="50" widthrequest="50">
                            <grid grid.column="1" rowspacing="1" grid.row="0" padding="10,0,0,0" rowdefinitions="*,*" verticaloptions="Center">
                                <label linebreakmode="NoWrap" textcolor="#474747" grid.row="0" text="{Binding ContactName}">
                                <label grid.row="1" grid.column="0" textcolor="#474747" linebreakmode="NoWrap" text="{Binding ContactNumber}">
                            </label></label></grid>
                        </grid>
                    </datatemplate>
                </syncfusion:sflistview.itemtemplate>
            </syncfusion:sflistview>

2. In the C# code, get the ListViewScrollView using the ListView.GetScrollView helper method. Then, update the ScrollDirection value based on the previous offset.

C#

public class ListViewBehavior : Behavior<sflistview>
{
	#region Fields
	ContactsViewModel viewModel;
	ListViewScrollView scrollview;
	double previousOffset;
	public SfListView listview { get; private set; }
	#endregion

	#region Overrides
	protected override void OnAttachedTo(SfListView bindable)
	{
		base.OnAttachedTo(bindable);
		listview = bindable as SfListView;
		viewModel = new ContactsViewModel();
		listview.BindingContext = viewModel;
		scrollview = listview.GetScrollView();
		scrollview.Scrolled += Scrollview_Scrolled;
	}

	protected override void OnDetachingFrom(SfListView bindable)
	{
		base.OnDetachingFrom(bindable);
		scrollview.Scrolled -= Scrollview_Scrolled;
		scrollview = null;
		listview = null;
		viewModel = null;
	}
	#endregion

	#region Call back

	private void Scrollview_Scrolled(object sender, ScrolledEventArgs e)
	{
		if (e.ScrollY == 0)
			return;

		if (previousOffset >= e.ScrollY)
		{
			// Up direction  
			viewModel.ScrollDirection = "Up Direction";
		}
		else
		{
			//Down direction 
			viewModel.ScrollDirection = "Down Direction";
		}

		previousOffset = e.ScrollY;
	}
	#endregion
}

In the above code, the previousOffset is a variable that stores the previous scroll position. The ScrollY property of the scrollView object gives the current scroll position. By comparing these two values, we can determine the scroll direction.

View Sample in GitHub

Conclusion

I hope you enjoyed learning about how to detect scroll direction in .NET MAUI ListView.

You can refer to our .NET MAUI ListView feature tour page to know about its other groundbreaking feature representations and documentation, and how to quickly get started for configuration specifications. You can also explore our .NET MAUI ListView example to understand how to create and manipulate data.

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