MVC远程控制器操作仅在表单提交时调用

Question

根据我的理解，我认为远程验证会在用户离开文本框后立即调用控制器操作。我正在尝试验证用户名（电子邮件）但仅在我提交表单时调用控制器操作（当我单击提交按钮时）。我想在离开电子邮件文本框后立即调用此功能。我在这里做错了什么？

视图模型

public class RegisterViewModel
{
    [Required(ErrorMessage = "Email is required")]
    [DataType(DataType.EmailAddress)]
    [Remote("IsEmailAvailable","Register", ErrorMessage = "Email is already registered, use forgot password to reset your password if this is the case.")]
    [Display(Name = "Email")]
    public string Username { get; set; }

    [Required(ErrorMessage = "First Name is required")]
    [Display(Name = "First Name")]
    public string FirstName { get; set; }

    [Required(ErrorMessage = "LastName is required")]
    [Display(Name = "Last Name")]
    public string LastName { get; set; }

    [DataType(DataType.Password)]
    [Required(ErrorMessage = "Password is required")]
    [Display(Name = "Password")]
    public string Password { get; set; }

    [DataType(DataType.Password)]
    [Required(ErrorMessage = "Password is required")]
    [System.ComponentModel.DataAnnotations.Compare("Password", ErrorMessage = "Passwords do not match")]
    [Display(Name = "Confirm Password")]
    public string ConfirmPassword { get; set; }

    [Required(ErrorMessage = "Business name is required")]
    [Display(Name = "Business Name")]
    public string BusinessName { get; set; }

    [Required(ErrorMessage = "Address Line 1 is required")]
    [Display(Name = "Address Line 1")]
    public string AddressLine1 { get; set; }

    [Display(Name = "Address Line 2")]
    public string AddressLine2 { get; set; }

    [Required(ErrorMessage = "Postcode is required")]
    [Display(Name = "Postcode")]
    public string PostCode { get; set; }

    [Required(ErrorMessage = "City is required")]
    [Display(Name = "City")]
    public string City { get; set; }

    [Required(ErrorMessage = "Country is required")]
    [Display(Name = "Country")]
    public string Country { get; set; }

    [Required(ErrorMessage = "Telephone number is required")]
    [Display(Name = "Telephone Number")]
    public string TelephoneNumber { get; set; }

    public bool EmailVerified { get; set; }

    public bool TelephoneNumberVerified { get; set; }

}

控制器操作

    [HttpGet]
    public JsonResult IsEmailAvailable(string username)
    {
        return Json(false, JsonRequestBehavior.AllowGet);
    }

查看

@using (Html.BeginForm("Register", "Register", FormMethod.Post, new { id = "frmRegister", @class = "frmRegister" }))
{
    @Html.AntiForgeryToken()
    <h2>Register</h2>
    @Html.ValidationSummary(false, "Some informations you have provided are not correct", new {@class = "alert alert-danger"})
    <div class="form-group">
        @Html.LabelFor(m => m.FirstName)
        @Html.TextBoxFor(m => m.FirstName, null, new {id = "txtFirstName", @class = "form-control", placeholder = "First Name"})
    </div>
    <div class="form-group">
        @Html.LabelFor(m => m.LastName)
        @Html.TextBoxFor(m => m.LastName, null, new {id = "txtLastName", @class = "form-control", placeholder = "Last Name"})
    </div>
    <div class="form-group">
        @Html.LabelFor(m => m.Username)
        @Html.TextBoxFor(m => m.Username, null, new {id = "txtEmail", @class = "form-control", placeholder = "Email", type="email"})
        @Html.ValidationMessageFor(m => m.Username)

    </div>
    <div class="form-group">
        @Html.LabelFor(m => m.Password)
        @Html.TextBoxFor(m => m.Password, null, new {id = "txtPassword", @class = "form-control", placeholder = "Password", type="password"})
    </div>
    <div class="form-group">
        @Html.LabelFor(m => m.ConfirmPassword)
        @Html.TextBoxFor(m => m.ConfirmPassword, null, new {id = "txtConfirmPassword", @class = "form-control", placeholder = "Password", type = "password"})
    </div>
    <div class="form-group">
        @Html.LabelFor(m => m.BusinessName)
        @Html.TextBoxFor(m => m.BusinessName, null, new { id = "txtBusinessName", @class = "form-control", placeholder = "Business Name" })
    </div>
    <div class="form-group">
        @Html.LabelFor(m => m.AddressLine1)
        @Html.TextBoxFor(m => m.AddressLine1, null, new {id = "txtAddressLine1", @class = "form-control", placeholder = "Address Line 1"})
    </div>
    <div class="form-group">
        @Html.LabelFor(m => m.AddressLine2)
        @Html.TextBoxFor(m => m.AddressLine2, null, new {id = "txtAddressLine1", @class = "form-control", placeholder = "Address Line 2" })
    </div>
    <div class="form-group">
        @Html.LabelFor(m => m.PostCode)
        @Html.TextBoxFor(m => m.PostCode, null, new {id = "txtPostcode", @class = "form-control", placeholder = "Postcode"})
    </div>
    <div class="form-group">
        @Html.LabelFor(m => m.City)
        @Html.TextBoxFor(m => m.City, null, new {id = "txtCity", @class = "form-control", placeholder = "City"})
    </div>
    <div class="form-group">
        @Html.LabelFor(m => m.Country)
        @Html.TextBoxFor(m => m.Country, null, new {id = "txtCountry", @class = "form-control", placeholder = "Country"})
    </div>
    <div class="form-group">
        @Html.LabelFor(m => m.TelephoneNumber)
        @Html.TextBoxFor(m => m.TelephoneNumber, null, new {id = "txtTelephoneNumber", @class = "form-control", placeholder = "Telephone Number"})
    </div>
    <button type="submit" class="btn btn-success btnRegister">Register</button>
    }

    @Scripts.Render("~/bundles/jquery")
    @Scripts.Render("~/bundles/bootstrap")
    @Scripts.Render("~/bundles/jqueryval")
    @Styles.Render("~/Content/css")