Activity: Implementing Your Own IActionResult

Scenario

You want to learn how to access the underlying stream of response of a string.

Aim

Write an activity result that would capitalize the given string.

Steps for completion

1. First, add the following class to your projects:

public class UpperStringActionResult : ActionResult
{
  readonly string str;
  public UpperStringActionResult(string str)
  {
    this.str = str;
  }
  public override void ExecuteResult(ActionContext context)
  {
    var upperStringBytes =
    Encoding.UTF8.GetBytes(str.ToUpper());
    context.HttpContext.Response.Body.Write(
    upperStringBytes, 0, upperStringBytes.Length);
  }
}

2. Then, revise your controller action, as follows:

public IActionResult IndexUpper()
{
  return new UpperStringActionResult("Hello World! I am learning MVC!");
}

3. Then, run your application. You'll get the following output:

As you can see, all letters are in capitals.