How to get Input control value in controller's Index method asp.net core-CodePudding

I am working on captcha authentication. I want to get user entered captcha value in controller's Index method. Below is my cshtml file code

@{
    ViewData["Title"] = "Home Page";
 }
<div >
   <label for="captcha"><b>Enter chaptcha -  </b></label>
   <label id="lblshowCaptcha"><b>@ViewData["captcha"]</b></label>
   <input id="txtCapValue" type="text" placeholder="Enter captcha" name="cap" required>
     <br/>
   <button  type="submit">Login</button>
     <br />
</div>

When user entering captcha value in txtCapValue and click submit button I need that value in controller. Here is my controller

public IActionResult Index()
{
    randnumber = RandomString(6);
    ViewData["captcha"] = randnumber;
    return View();
}

how can I get txtCapValue input control value when user click on submit button ?

CodePudding user response：

One of the easy ways using the