Prefix Characters Constraint

22 Aug 20226 minutes to read

Prefix Characters Constraint in Xamarin SfAutoComplete

Instead of displaying suggestion list on every character entry, matches can be filtered and displayed after a few character entries. This can be done by MinimumPrefixCharacters property and its default value is 1.

XAML

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:autocomplete="clr-namespace:Syncfusion.SfAutoComplete.XForms;assembly=Syncfusion.SfAutoComplete.XForms"
             xmlns:ListCollection="clr-namespace:System.Collections.Generic;assembly=netstandard"
             xmlns:local="clr-namespace:AutocompleteSample"
             x:Class="AutocompleteSample.MainPage">
    <StackLayout VerticalOptions="Start" 
                 HorizontalOptions="Start" 
                 Padding="30">
        <autocomplete:SfAutoComplete
	           x:Name="autoComplete"
	           HeightRequest="40"
               MinimumPrefixCharacters="3">
            <autocomplete:SfAutoComplete.AutoCompleteSource>
                <ListCollection:List x:TypeArguments="x:String">
                    <x:String>Antigua and Barbuda</x:String>
                    <x:String>American Samoa</x:String>
                    <x:String>Afghanistan</x:String>
                    <x:String>Antarctica</x:String>
                    <x:String>Argentina</x:String>
                    <x:String>Anguilla</x:String>
                    <x:String>Albania</x:String>
                    <x:String>Algeria</x:String>
                    <x:String>Andorra</x:String>
                    <x:String>Angola</x:String>
                </ListCollection:List>
            </autocomplete:SfAutoComplete.AutoCompleteSource>
        </autocomplete:SfAutoComplete>
    </StackLayout>
</ContentPage>

C#

using Syncfusion.SfAutoComplete.XForms;
using System.Collections.Generic;
using Xamarin.Forms;

namespace AutocompleteSample
{
    public partial class MainPage : ContentPage
    {
        public MainPage()
        {
            InitializeComponent();
            StackLayout stackLayout = new StackLayout()
            {
                VerticalOptions = LayoutOptions.Start,
                HorizontalOptions = LayoutOptions.Start,
                Padding = 30
            };

            SfAutoComplete autoComplete = new SfAutoComplete()
            {
                HeightRequest = 40,
                MinimumPrefixCharacters = 3,
                AutoCompleteSource = new List<string>()
                {
                    "Antigua and Barbuda",
                    "American Samoa",
                    "Afghanistan",
                    "Antarctica",
                    "Argentina",
                    "Anguilla",
                    "Albania",
                    "Algeria",
                    "Andorra",
                    "Angola"
                }
            };
            stackLayout.Children.Add(autoComplete);
            this.Content = stackLayout;
        }
    }
}

NOTE

You can refer to our Xamarin AutoComplete feature tour page for its groundbreaking feature representations. You can also explore our Xamarin.Forms AutoComplete example to knows the functionalities of each feature.