JavaScript Interoperability in Blazor

-
JavaScript Interoperability in Blazor

This blog is going to explain JavaScript Interoperability in Blazor. Sometimes it is necessary to use JavaScript in Blazor; you can not avoid that. To use the JavaScript in Blazor, you have to use the IJSRuntime instance via the dependency injection. The InvokeAsync method helps to call the JavaScript function.

Let's see how to use JavaScript in Blazor.

Step1: Create a new Blazor WebAssembly App
In Visual Studio -> Create a New Project -> Blazor App. Provide Project name and Location. Then click the Create button. It will display the Create a New Blazor app window. In there, select 'Blazor WebAssembly App';
Blazor WebAssembly App

Step 2: Create JavaScript File
In this step I have created a javascript file with the name SampleJavaScript.js, under wwwroot -> Scripts folder. The following is a code of simple javascript code for adding two integer numbers.

\wwwroot\Scripts\SampleJavaScript.js
function CalulateSum(firstValue, secondValue) {
    alert(firstValue + secondValue);
}

Step 3: JavaScript reference
In this step, I have added the JavaScript reference to the application. For that, I included the javascript reference to the index.html page.

\wwwroot\index.html
<body>
    <app>Loading...</app>

    <div id="blazor-error-ui">
        An unhandled error has occurred.
        <a href="" class="reload">Reload</a>
        <a class="dismiss">🗙</a>
    </div>
    <script src="_framework/blazor.webassembly.js"></script>
    <script src="Scripts/SampleJavaScript.js"></script>
</body>

Step 4: Calculate Page
The following is a calculate page code. Here I have injected the IJSRuntime instence using @inject directive. And added two textbox to collect the input value and one button to display the calculated value. Using InvokeVoidAsync() method I have called the CalulateSum Javacript method and pass the input value.

\Pages\Calculate.razor
@page "/calculate"

@inject IJSRuntime jsRuntime

<h4>JavaScript Interoperability in Blazor</h4>
<br />
<br />
First Value:
<input @bind="firstValue" />
<br />
<br />
Second Value:
<input @bind="secondValue" />
<br />
<br />
<button type="button" class="btn btn-info" @onclick="ShowSum">Sum</button>

@code {
    private int firstValue;
    private int secondValue;

    public async Task ShowSum()
    {
        await jsRuntime.InvokeVoidAsync("CalulateSum", firstValue, secondValue);
    }
}

Output
The following is an output of the above code. Here you can see when the user clicks on the sum button, it gives the result in JavaScript alert message.

JavaScript Interoperability in Blazor

I hope this helps you. Keep coding.

Comments

Post a Comment

Popular posts from this blog

Entity Framework Core (EF) with SQL Server LocalDB

-
Image
This blog is going to illustrate how to implement Entity Framework (EF) Core with SQL Server LocalDB. The Entity Framework Core enables access to data from the database. This allows developers to avoid having to write most of the data access code. And the SQL Server LocalDB works similarly to the SQL SERVER with few features. You can get the LocalDB when you install visual studio or visual studio express. You can find the .mdf and _log.ldf files in the C:/Users/{user} directory. Let see how to create a SQL Server LocalDB and implement Entity Framework Core Step 1: The first step is to add a connection. In the menu -> click Tools and select Connect to Database It will display the Add Connection window. Enter (localdb)\mssqllocaldb in the server name textbox. Then in the Select or enter a database, select master and click ok Now in the server explorer, you can find the master DB containing Tables, Views, Stored
Read more

Creating a C# Azure Function with Visual Studio: Step-by-Step Guide

-
Image
Azure Functions is a serverless computing service provided by Microsoft Azure, enabling developers to create applications without worrying about server maintenance and infrastructure. Using Azure Functions, developers can create event-driven, scalable, and highly available applications. In this blog, we will explain how to create an Azure function using Visual Studio 2022 with C# as the programming language. Before we begin, there are some prerequisites to consider. You will need an active Azure account subscription, Visual Studio 2022, and Azure Functions and Azure Storage extensions for Visual Studio. Step 1: Creating a new Azure Functions project in Visual Studio To create a new project, open Visual Studio 2022 and click on "Create a new project". In the "Create a new project" window, search for "Azure Functions" and select "Azure Functions" from the list of project templates. Next, enter the project name, which
Read more

Exploring EventCallback in Blazor: Building Interactive Components

-
Image
Introduction: Blazor is a powerful framework for building web applications using C# instead of JavaScript. It allows developers to create interactive and dynamic user interfaces with ease. One of the key features in Blazor is the EventCallback<T> pattern, which enables communication between components through events. In this blog post, we will explore how to use the EventCallback<T> pattern in Blazor by building a simple example. Creating the Event-Driven Component: Let's start by creating a Blazor component called MyComponent. This component will raise an event when a button is clicked. Here's the code for the MyComponent.razor file: MyComponent.razor < h3 > My Component < / h3 > < button @onclick = " RaiseEvent " > Raise Event < / button > @code { [ Parameter ] public EventCallback < string > EventRaised { get ; set ; } private async Task RaiseEvent ( ) { await EventRais
Read more