In this article, we will add a Razor component to our existing .NET Core MVC project.
 
Blazor is a framework for building interactive client-side web UI with .NET. With it, you can:

    Create rich interactive UIs using C# instead of JavaScript.
    Share server-side and client-side app logic written in .NET.
    Render the UI as HTML and CSS for wide browser support, including mobile browsers.

Blazor apps are based on components. A component in Blazor is an element of UI, such as a page, dialog, or data entry form.
 
Let's start with a few simple steps.

Step 1

Step 2

Step 3
Add a Microsoft.AspNetCore.Components reference to your project if not available.

Step 4
Add a Component folder inside the view/shared folder, then add a Razor component.

Step 5
For the Razor component we have written a simple method named "GetData", which you can see below. Also, I have made 2 public properties for getting data from the view and decorating it with the attribute name as Parameter.

    <div class="card-header">  
      
        <h3>DataComponent</h3>  
        <button @onclick="Getdata" class="btn btn-dark">Click to GetData    </button>  
    </div>  
    <div class="card-body">  
        <br />  
        <div class="@style">@Data </div>  
    </div>  
      
    @code {  
        [Parameter]  
        public string Data { get; set; } = string.Empty;  
        [Parameter]  
        public string style { get; set; }  
        private void Getdata()  
        {  
            Data = "I am Working";  
            style = "badge-success";  
      
        }  
      
    }  

Step 6
The below code you need to add to your _Layout.cshtml  
This is for registering Blazor to your web application:
    <base href="~/" />  
    <script src="_framework/blazor.server.js"></script>

Step 7
Add simple _Imports.razor file to your root of the project which consists of the below code. These namespaces are required to access the component features over your components.

    @using System.Net.Http  
    @using Microsoft.AspNetCore.Authorization  
    @using Microsoft.AspNetCore.Components.Authorization  
    @using Microsoft.AspNetCore.Components.Forms  
    @using Microsoft.AspNetCore.Components.Routing  
    @using Microsoft.AspNetCore.Components.Web  
    @using Microsoft.JSInterop  
      
    @using System.IO   

Step 8
Add services.AddServerSideBlazor(); to your startup file method name ConfigureServices.
Add endpoints.MapBlazorHub(); to your Configure method.
    public void ConfigureServices(IServiceCollection services)  
        {   
            services.AddServerSideBlazor();  
            services.AddControllersWithViews();  
        }  
      
        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.  
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)  
        {  
            if (env.IsDevelopment())  
            {  
                app.UseDeveloperExceptionPage();  
            }  
            else  
            {  
                app.UseExceptionHandler("/Home/Error");  
                // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.  
                app.UseHsts();  
            }  
            app.UseHttpsRedirection();  
            app.UseStaticFiles();  
      
            app.UseRouting();  
      
            app.UseAuthorization();  
      
            app.UseEndpoints(endpoints =>  
            {  
                endpoints.MapControllerRoute(  
                    name: "default",  
                    pattern: "{controller=Home}/{action=Index}/{id?}");   
                endpoints.MapBlazorHub();  
            });  
      
        }  

Step 9
The last step is to render components on your View page.
You can see that I am passing 2 parameters as requested in our DataViewComponent.razor file
    @{  
        ViewData["Title"] = "Home Page";  
    }  
    <div class="text-center">  
        <h1 class="display-4">Welcome</h1>  
          
    </div>  
      
    <div class="card">  
         
            @(await Html.RenderComponentAsync<BlazorComponentProject.Views.Shared.Components.DataViewComponent>(RenderMode.ServerPrerendered,new {  Data="I came from Index",style= "badge-danger" }))  
               
          
    </div>