Xamarin.Forms Slider Lock

Hello, my Xamarin friends!

Today, I am here with another new post in which I am going to tell you how to customize the Slider Lock. So, let's start.

So, we will first create a class whose name "SlideToActView" and then we will write a code in "C #".

namespace XamarinControlsApp.SliderLock
{
    public class SlideToActView : AbsoluteLayout
    {
        public static readonly BindableProperty ThumbProperty =
            BindableProperty.Create(
                nameof(Thumb), typeof(View), typeof(SlideToActView),
                defaultValue: default(View));

        public View Thumb
        {
            get { return (View)GetValue(ThumbProperty); }
            set { SetValue(ThumbProperty, value); }
        }

        public static readonly BindableProperty TrackBarProperty =
            BindableProperty.Create(
                nameof(TrackBar),
                typeof(View),
                typeof(SlideToActView),
                defaultValue: default(View));

        public View TrackBar
        {
            get { return (View)GetValue(TrackBarProperty); }
            set { SetValue(TrackBarProperty, value); }
        }

        public static readonly BindableProperty FillBarProperty =
            BindableProperty.Create(
                nameof(FillBar), typeof(View), typeof(SlideToActView),
                defaultValue: default(View));

        public View FillBar
        {
            get { return (View)GetValue(FillBarProperty); }
            set { SetValue(FillBarProperty, value); }
        }

        private PanGestureRecognizer _panGesture = new PanGestureRecognizer();
        private View _gestureListener;

        public SlideToActView()
        {
            _panGesture.PanUpdated += OnPanGestureUpdated;
            SizeChanged += OnSizeChanged;

            _gestureListener = new ContentView { BackgroundColor = Color.White, Opacity = 0.05 };
            _gestureListener.GestureRecognizers.Add(_panGesture);
        }

        public event EventHandler SlideCompleted;

        private const double _fadeEffect = 0.5;
        private const uint _animLength = 50;
        async void OnPanGestureUpdated(object sender, PanUpdatedEventArgs e)
        {
            if (Thumb == null || TrackBar == null || FillBar == null)
                return;

            switch (e.StatusType)
            {
                case GestureStatus.Started:
                    await TrackBar.FadeTo(_fadeEffect, _animLength);
                    break;

                case GestureStatus.Running:
                    // Translate and ensure we don't pan beyond the wrapped user interface element bounds.
                    var x = Math.Max(0, e.TotalX);
                    if (x > (Width - Thumb.Width))
                        x = (Width - Thumb.Width);

                    //Uncomment this if you want only forward dragging.
                    //if (e.TotalX < Thumb.TranslationX)
                    //    return;
                    Thumb.TranslationX = x;
                    SetLayoutBounds(FillBar, new Rectangle(0, 0, x + Thumb.Width / 2, this.Height));
                    break;

                case GestureStatus.Completed:
                    var posX = Thumb.TranslationX;
                    SetLayoutBounds(FillBar, new Rectangle(0, 0, 0, this.Height));

                    // Reset translation applied during the pan
                    await Task.WhenAll(new Task[]{
                    TrackBar.FadeTo(1, _animLength),
                    Thumb.TranslateTo(0, 0, _animLength * 2, Easing.CubicIn),
                });

                    if (posX >= (Width - Thumb.Width - 10/* keep some margin for error*/))
                        SlideCompleted?.Invoke(this, EventArgs.Empty);
                    break;
            }
        }

        void OnSizeChanged(object sender, EventArgs e)
        {
            if (Width == 0 || Height == 0)
                return;
            if (Thumb == null || TrackBar == null || FillBar == null)
                return;


            Children.Clear();

            SetLayoutFlags(TrackBar, AbsoluteLayoutFlags.SizeProportional);
            SetLayoutBounds(TrackBar, new Rectangle(0, 0, 1, 1));
            Children.Add(TrackBar);

            SetLayoutFlags(FillBar, AbsoluteLayoutFlags.None);
            SetLayoutBounds(FillBar, new Rectangle(0, 0, 0, this.Height));
            Children.Add(FillBar);

            SetLayoutFlags(Thumb, AbsoluteLayoutFlags.None);
            SetLayoutBounds(Thumb, new Rectangle(0, 0, this.Width / 5, this.Height));
            Children.Add(Thumb);

            SetLayoutFlags(_gestureListener, AbsoluteLayoutFlags.SizeProportional);
            SetLayoutBounds(_gestureListener, new Rectangle(0, 0, 1, 1));
            Children.Add(_gestureListener);
        }
    }
}

Please make sure to add view reference....

xmlns:local="clr-namespace:XamarinControlsApp.SliderLock"

Then, write the XAML code in main page.

<?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:local1="clr-namespace:XamarinControlsApp"
             x:Class="XamarinControlsApp.MainPage"
             xmlns:local="clr-namespace:XamarinControlsApp.SliderLock"
             Title="Slider Lock">
    <StackLayout Margin="35">
        <local:SlideToActView HeightRequest="50"
                              SlideCompleted="Handle_SlideCompleted">
            <local:SlideToActView.Thumb>
                <Frame CornerRadius="15"
                       HasShadow="false"
                       BackgroundColor="Silver"
                       Padding="0">
                    <Image Source="icon.png"
                           HorizontalOptions="Center"
                           VerticalOptions="Center"
                           HeightRequest="35"
                           WidthRequest="35" />
                </Frame>
            </local:SlideToActView.Thumb>

            <local:SlideToActView.TrackBar>
                <Frame CornerRadius="15"
                       HasShadow="false"
                       BackgroundColor="Gray"
                       Padding="0">
                    <Label Text="Sliding to Unlock"
                           HorizontalOptions="CenterAndExpand"
                           VerticalOptions="CenterAndExpand" />
                </Frame>
            </local:SlideToActView.TrackBar>

            <local:SlideToActView.FillBar>
                <Frame CornerRadius="15"
                       HasShadow="false"
                       BackgroundColor="Green"
                       Padding="0" />
            </local:SlideToActView.FillBar>
        </local:SlideToActView>
        <Label x:Name="MessageLbl"
               FontAttributes="Bold"
               TextColor="Green" />
    </StackLayout>
</ContentPage>

And then, write the following code for sliding event.

public async void Handle_SlideCompleted(object sender, System.EventArgs e)
        {
            MessageLbl.Text = "Unlock Successfully!!";
            await Navigation.PushAsync(new NextPage());
        }

You should have your Slider Lock working!! If you want to watch a related video, click here Custom Slider Lock.