在登录失败后将username传递回MVC view/textbox

[HttpPost]
public ActionResult Login(LoginModel model)
{
    if (!IsValidUser(model.Username, model.Password))
    {
        ViewBag.Username = model.Username; // 将username传递给View
        return View(model);
    }
    // 登录成功的逻辑
    return RedirectToAction("Index", "Home");
}

@model LoginModel

@using (Html.BeginForm("Login", "Account", FormMethod.Post))
{
    @Html.TextBoxFor(m => m.Username, new { @value = ViewBag.Username }) // 使用传递的username填充textbox
    @Html.PasswordFor(m => m.Password)
    <input type="submit" value="Login" />
}