Ankit Sharma, 2020.05.28 Updated to .NET Core 3.2 Preview-1
Tutorial: https://www.c-sharpcorner.com/article/getting-started-with-blazor/
Github: https://github.com/AnkitSharma-007/ASPCore.BlazorDemo
Calculator module using Blazor
- Install .NET Core SDK from here or SDK preview
- Install Visual Studio Community 2019 Latest with the ASP.NET and web development workload selected from here or preview
- Entity Framework Core Tools >> NuGet or on command-line tools: dotnet tool install –global dotnet-ef
(Install ASP.NET Core Blazor Language Services extension from here not needed (needed in VS2019) older ?)) - SQL Server 2012 or above
STEP 1.
- VS2019 >> File >> New >> Project
- Select Blazor App C# (older : .NET Core inside Visual C# menu from the left panel)
- Select Blazor App (older : “ASP.NET Core Web Application”) from available project types.
- Put the name of the project as BlazorDemoCalc and J:\netcore\source\repos
- Click “Blazor WebAssembly App”, “ASP.NET Core hosted”, “Progressive web app”
STEP 2. Client proj, Pages folder. We will be adding our view pages to this folder only. These pages will be rendered on the web.
Execute the program – displays navigation links Home, Counter, Fetch data in navigation menu are displayed.
- Right click on Pages folder in Client proj >> select Add >> New Item
- “Add New Item” dialog box will open. Selected is Visual C# from the left panel (old : select Web) ,
- select Razor Component from templates panel and put the name as Calculator (old : Razor View – empty)
J:\netcore\source\repos\BlazorDemoCalc\BlazorDemo\Pages\Calculator.razor
@page "/calculator"
<h1>Basic Calculator Demo Using Blazor</h1>
<hr />
<div>
<div class="row">
<div class="col-md-3">
<p>First Number</p>
</div>
<div class="col-md-4">
<input placeholder="Enter First Number" @bind="@num1" />
</div>
</div>
<br />
<div class="row">
<div class="col-md-3">
<p>Second Number</p>
</div>
<div class="col-md-4">
<input placeholder="Enter Second Number" @bind="@num2" />
</div>
</div>
<br />
<div class="row">
<div class="col-md-3">
<p>Result</p>
</div>
<div class="col-md-4">
<input readonly @bind="@finalresult" />
</div>
</div>
<br /> <div class="row"> <div class="col-md-2"> <button @onclick="AddNumbers" class="btn btn-light">Add (+)</button> </div> <div class="col-md-2"> <button @onclick="SubtractNumbers" class="btn btn-primary">Subtract (−)</button> </div> <div class="col-md-2"> <button @onclick="MultiplyNumbers" class="btn btn-success ">Multiply (X)</button> </div> <div class="col-md-2"> <button @onclick="DivideNumbers" class="btn btn-info">Divide (/)</button> </div> </div> </div> @code { string num1; string num2; string finalresult; void AddNumbers() { finalresult = (Convert.ToDouble(num1) + Convert.ToDouble(num2)).ToString(); } void SubtractNumbers() { finalresult = (Convert.ToDouble(num1) - Convert.ToDouble(num2)).ToString(); } void MultiplyNumbers() { finalresult = (Convert.ToDouble(num1) * Convert.ToDouble(num2)).ToString(); } void DivideNumbers() { if (Convert.ToDouble(num2) != 0) { finalresult = (Convert.ToDouble(num1) / Convert.ToDouble(num2)).ToString(); } else { finalresult = "Cannot Divide by Zero"; } } }
Let’s understand Calculator.razor
On the top, we are defining the route of this page using @page directive. So in this module, if we append “/calculator” to base URL then we will be redirected to this page.
Then we have defined the HTML section to read two numbers from the user and display the result in another textbox. The attribute “bind” is used to bind the value entered in the textbox to the variables we have defined. We also created four buttons to perform our basic arithmetic operations. We are calling our business logic methods on button click.
At the bottom of the page, we have a @code (was functions) section which contains all our business logic. We have declared three variables, two variables to read the value from the user and another one to display the result. We have also defined four methods to handle addition, subtraction, multiplication, and division. The “bind” attribute will work only for string variables not for floating point values. Hence, we need to convert a string to double to perform our arithmetic operations.
STEP 3. Add the link to our “calculator” page in the navigation menu, open /Shared/NavMenu.razor page
J:\netcore\source\repos\BlazorDemoCalc\BlazorDemo\Shared\NavMenu.razor
and put the following BLUE COLORED code into it.
<div class="top-row pl-4 navbar navbar-dark">
<a class="navbar-brand" href="">BlazorDemoCalcDev</a>
<button class="navbar-toggler" @onclick="ToggleNavMenu">
<span class="navbar-toggler-icon"></span>
</button>
</div>
<div class="@NavMenuCssClass" @onclick="ToggleNavMenu">
<ul class="nav flex-column">
<li class="nav-item px-3">
<NavLink class="nav-link" href="" Match="NavLinkMatch.All">
<span class="oi oi-home" aria-hidden="true"></span> Home
</NavLink>
</li>
<li class="nav-item px-3">
<NavLink class="nav-link" href="counter">
<span class="oi oi-plus" aria-hidden="true"></span> Counter
</NavLink>
</li>
<li class="nav-item px-3">
<NavLink class="nav-link" href="fetchdata">
<span class="oi oi-list-rich" aria-hidden="true"></span> Fetch data
</NavLink>
</li>
<li class="nav-item px-3">
<NavLink class="nav-link" href="calculator">
<span class="oi oi-plus" aria-hidden="true"></span> Calculator
</NavLink>
</li>
</ul>
</div>
@code {
private bool collapseNavMenu = true;
private string NavMenuCssClass => collapseNavMenu ? "collapse" : null;
private void ToggleNavMenu()
{
collapseNavMenu = !collapseNavMenu;
}
}
What is Blazor
What is WebAssembly
Why use Blazor
- Routing
- Layouts
- Forms and validation
- JavaScript interop
- Build on save during development
- Server-side rendering
- Dependency Injection
Using .NET for developing Client-side application has multiple advantages :
- .NET offers a range of API and tools across all platform that are stable and easy to use.
- The modern languages such as C# and F# offer a lot of features that make programming easier and interesting for developers.
- The availability of one of the best IDE in form of Visual Studio provides a great .NET development experience across multiple platforms such as Windows, Linux, and MacOS.
- .NET provides features such as speed, performance, security, scalability, and reliability in web development that makes full stack development easier.
See Fluxor https://github.com/mrpmorris/fluxor