Question

I am having some trouble with my code. Okay so I have an ASPx webpage. Right now i have drop down box that gets filled by a sql server from the model (via the controller). I have added a button and dropdownlist like below.

I am unable to return the selected value from the dropdownlist to the controller. Any help would be great

View:

<% = Html.DropDownList("Books") %>
<input type = "submit" value = "Update"/>

<h1> <%=TempData["BookName"]%> </h1>

Controller:

 public ActionResult Index(string bookName)
 {
   ViewData["BookName"] = new SelectList(_context.BookName.Select(a =>a.Book_Name).Distinct());

 if (!string.IsNullOrWhiteSpace(bookName))
 {
   ViewData["Books"] = _context.BookName.Where(b => b.Book_Name == bookName).ToList();
   UpdateBookNameTitle(bookName);
  }
  return View();
}

public ActionResult UpdateBookNameTitle(string bookName)
{
   TempData["BookName"] = bookName;
    return View("Home2"); 


}

Answer 1

You need to wrap you drop-down list and button into form (in view). Also change the name of drop-down to “bookName”, so MVC can map selected value to bookName action parameter:

<% using(Html.BeginForm("Index", "Home")) { %>
  <%= Html.DropDownList("bookName") %>
  <input type="submit" value="Update"/>
<% } %>

Without HTML form your submit button will not do POST requests to the server.