Xamarin.Forms - Working With RefreshView

Introduction

 

 

Xamarin.Forms code runs on multiple platforms, each of which has its own filesystem. This means that reading and writing files is most easily done using the native file APIs on each platform. Alternatively, embedded resources are a simpler solution to distribute data files with an app.

 

RefreshView (Pull to Refresh)

 

RefreshView is a container control that provides a pull to refresh functionality for scrollable content. Therefore, the child of a RefreshView must be a scrollable control, such as ScrollView, CollectionView, or ListView.

 

Prerequisites

• Visual Studio 2017 or later (Windows or Mac)

Setting up a Xamarin.Forms Project

 

Start by creating a new Xamarin.Forms project. You wíll learn more by going through the steps yourself.

 

Create a new or existing Xamarin forms(.Net standard) Project. With Android and iOS Platform.

 

 

Use RefreshView

 

Make sure your controls should be within ScrollView. 

<RefreshView IsRefreshing="{Binding IsRefreshing}" RefreshColor="Red"
             Command="{Binding RefreshViewCommand}">
            <ScrollView>
           // Your Controls
      </ScrollView>
</RefreshView>

Setting up the User Interface

 

Here, Add RefreshView in your View. Make sure your content should be within ScrollView.

 

MainPage.Xaml

<?xml version="1.0" encoding="UTF-8"?>
<Pages:XMonkeyBasePage xmlns="http://xamarin.com/schemas/2014/forms"
                       xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
                       xmlns:Behavior="clr-namespace:Prism.Behaviors;assembly=Prism.Forms"
                       xmlns:Pages="clr-namespace:XMonkey.Common.Pages"
                       xmlns:CustomViews="clr-namespace:XMonkey.Common.CustomViews"
                       x:Class="XMonkey.Views.BlogFeedPage">
    <NavigationPage.TitleView>
        <CustomViews:XMonkeyTitleView />
    </NavigationPage.TitleView>
    <Pages:XMonkeyBasePage.Behaviors>
        <Behavior:EventToCommandBehavior  EventName="Appearing" Command="{Binding RefreshCommand}"/>
        <Behavior:EventToCommandBehavior EventName="Disappearing" Command="{Binding CleanUpCommand}"/>
    </Pages:XMonkeyBasePage.Behaviors>
    <Pages:XMonkeyBasePage.PageContent>

        <RefreshView IsRefreshing="{Binding IsRefreshing}"
             Command="{Binding RefreshViewCommand}">

            <ScrollView>

        <FlexLayout Direction="Column" Margin="0,100,0,0"
                AlignItems="Center">

            <Label FontSize="Large"  Text="{Binding Name}"/>

        </FlexLayout>
        </ScrollView>
       </RefreshView>
    </Pages:XMonkeyBasePage.PageContent>
</Pages:XMonkeyBasePage>

Add RefreshCommand

 

Now, Add RefreshCommand for your RefreshView. This Command will perform while pull to refresh. After Refresh your data don't forget set IsRefreshing=false;

 

MainPageViewModel.cs 

namespace XMonkey.ViewModels
{
    public class BlogFeedPageViewModel:BaseViewModel
    {
        #region Fields

        private string _name;
        private bool _isRefreshing;
        private Command _refreshViewCommand;
        #endregion

        #region Constructor

        public BlogFeedPageViewModel()
        {
        }

        #endregion

        #region Properties

        public string Name
        {
            get => _name;
            set => SetProperty(ref _name, value);
        }

        public bool IsRefreshing
        {
            get => _isRefreshing;
            set => SetProperty(ref _isRefreshing, value);
        }

        public Command RefreshViewCommand
        {
            get
            {
                return _refreshViewCommand ?? (_refreshViewCommand = new Command(() =>
                {
                    this.RefreshData();
                }));
            }
        }

        #endregion

        #region Methods

        private void RefreshData()
        {
            //Do your stuff
            this.Name = "Delpin";
            this.IsRefreshing = false;
        }

        #endregion

    }
}

Click the "Play" button to try it out.

 

 

Change Refresh ActivityIndicator Color

 

Now, Change Refresh ActivityIndicator Color. Set RefreshColor="Color". Check the below code:

 

MainPage.xaml

<RefreshView IsRefreshing="{Binding IsRefreshing}" RefreshColor="Red"
             Command="{Binding RefreshViewCommand}">
            <ScrollView>
        <FlexLayout Direction="Column" Margin="0,100,0,0"
                AlignItems="Center">

            <Label FontSize="Large"  Text="{Binding Name}"/>

        </FlexLayout>
    </ScrollView>
</RefreshView>

Click the "Play" button to try it out.

 

 

Wow, it's working.

 

I hope you have understood how to use implement Pull to Refresh the Entire Page using RefreshView in Xamarin.Forms.

 

Thanks for reading. Please share your comments and feedback. Happy Coding