ASP.NET plain text
last modified October 18, 2023
In this article we show how to serve plain text in an ASP.NET application.
ASP.NET is a cross-platform, high-performance, open-source framework for building modern, cloud-enabled, web applications. It is developed by Microsoft.
Content type
Content type, or media type, is a string sent along with a file indicating the type of the file. It describes the content format; for example, an HTML file might be labeled text/html, or an image file as image/png). It serves the same purpose as filename extensions on Windows.
The content-type header values is used to indicate the
media type of the resource. The text/plain; charset=utf-8 is used
for text files.
ASP.NET plain text example
The easiest way to return plain text is with lambda expressions.
$ dotnet new web --no-https -o PlainTextEx
We create a new ASP.NET web application.
var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();
app.MapGet("/", () => "home page\n");
app.MapGet("/about", () => Results.Content("about page\n"));
app.MapGet("/contact", () => "contact page\n");
app.Run("http://localhost:3000");
We have three mappings. The mappings use lambdas.
app.MapGet("/", () => "home page\n");
In the first mapping, we send a string. ASP.NET automatically sets the status code and the content type.
app.MapGet("/about", () => Results.Content("about page\n"));
We can also use the Results.Content helper for a more explicit
intent.
$ dotnet watch
We start the application.
$ curl localhost:3000 -i HTTP/1.1 200 OK Content-Type: text/plain; charset=utf-8 Date: Tue, 27 Sep 2022 10:28:43 GMT Server: Kestrel Transfer-Encoding: chunked home page $ curl localhost:3000/about -i HTTP/1.1 200 OK Content-Length: 11 Content-Type: text/plain; charset=utf-8 Date: Tue, 27 Sep 2022 10:25:54 GMT Server: Kestrel about page $ curl localhost:3000/contact -i HTTP/1.1 200 OK Content-Type: text/plain; charset=utf-8 Date: Tue, 27 Sep 2022 10:29:00 GMT Server: Kestrel Transfer-Encoding: chunked contact page
We create GET requests with curl.
ASP.NET plain text example II
In the second example, we send plain text response from a controller.
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddControllers();
var app = builder.Build();
app.UseRouting();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers();
});
app.Run("http://localhost:3000");
In Program.cs, we set up the controllers.
using Microsoft.AspNetCore.Mvc;
namespace PlainTextEx.Controllers;
public class HomeController : Controller
{
[Produces("text/plain")]
[HttpGet("/")]
public IActionResult Home()
{
string msg = "home page\n";
return Ok(msg);
}
[HttpGet("about")]
public ContentResult About()
{
return Content("about page\n");
}
}
We have two action methods.
[Produces("text/plain")]
[HttpGet("/")]
public IActionResult Home()
{
string msg = "home page\n";
return Ok(msg);
}
With Produces attribute, we set the content type. We put the message
into the Ok method, which sets the OK status code.
[HttpGet("about")]
public ContentResult About()
{
return Content("about page\n");
}
Alternatively, we can also use the ContentResult and
Content to produce plaint text response.
$ curl localhost:3000 -i HTTP/1.1 200 OK Content-Type: text/plain; charset=utf-8 Date: Tue, 27 Sep 2022 10:22:49 GMT Server: Kestrel Transfer-Encoding: chunked home page
We generate a GET request to the home page.
$ curl localhost:3000/about -i HTTP/1.1 200 OK Content-Length: 11 Content-Type: text/plain; charset=utf-8 Date: Tue, 27 Sep 2022 10:23:39 GMT Server: Kestrel about page
We generate a GET request to the about page.
In this article we have shown how to serve plain text in an ASP.NET application.
