Xamarin.Forms - Validation Using Xamarin Community Toolkit - Part Two

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.

• Xamarin.Forms - Validation Using Xamarin Community Toolkit

Xamarin Community Toolkit

Xamarin Community Toolkit is a collection of reusable elements for mobile development with Xamarin.Forms, including animations, behaviors, converters, effects, and helpers. It simplifies and demonstrates common developer tasks when building iOS, Android, macOS, WPF, and UWP apps using Xamarin.Forms.

The Xamarin Community Toolkit is available as a Visual Studio NuGet package for new or existing Xamarin.Forms projects.

Validation Behaviours

1. CharactersValidationBehavior
2. EmailValidationBehavior
3. MultiValidationBehavior
4. NumericValidationBehavior
5. RequiredStringValidationBehavior
6. TextValidationBehavior
7. UriValidationBehavior

References

• https://docs.microsoft.com/en-us/xamarin/community-toolkit/behaviors/
• https://github.com/xamarin/XamarinCommunityToolkit

Prerequisites

• Visual Studio 2017 or later (Windows or Mac)

Let's Start,

Setting up a Xamarin.Forms Project

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

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

Install Xamarin.CommunityToolkit NuGet

Install the following Nuget from Nuget Manager In your Visual Studio.

Xamarin.CommunityToolkit

NumericValidation

NumericValidationBehavior is a behavior that allows the user to determine if text input is a valid numeric value. For example, an Entry control can be styled differently depending on whether a valid or an invalid numeric input is provided.

XAML code

<Entry>
  <Entry.Behaviors>
    <xct:NumericValidationBehavior InvalidStyle="{StaticResource InvalidEntryStyle}" MinimumValue="1.0" MaximumValue="100.0" />
  </Entry.Behaviors>
</Entry>

More details

https://docs.microsoft.com/en-us/xamarin/community-toolkit/behaviors/numericvalidationbehavior

Result