Sample code is given below:
@using (Html.BeginForm("Index", "Home"))
{
@Html.ListBoxFor(m => m.SelectedCountry, new SelectList(Model.CountryList, "Value", "Text", Model.CountryList.SelectedValue), new { @Id = "lstcountry", @style = "width:200px;height:60px;" })
<br /> <input type="submit" value="Submit" title="submit" />
<input style="color: black; " value="@ViewBag.Country"></input>
}
For more information visit:
http://mvc-model.blogspot.in/2013/07/how-to-bind-listbox-in-mvc3-razor-with.html[
^]
If you want as you select a value from listbox simultaneously value of textbox should change in this case you can use javascript/jQuery also.
Hope it will help you...if any problem post it.