【问题标题】：return type is getting null while having data passed in it返回类型在传递数据时变为空
【发布时间】：2018-12-20 07:57:03
【问题描述】：

这是我在 VS2013 中使用 mvc 的表单，我对这里发生的事情有点困惑，它在我传递所需数据时返回空字段，虽然当字段为空但它有数据时可以它应该被成功发送，但它不工作
伙计们请帮助我让我的这段代码正常工作

查看

@using (Html.BeginForm("RegUser", "User", FormMethod.Post, new { @id = "myForm" }))
{
    @Html.AntiForgeryToken()
    @Html.ValidationSummary(true)
    <div class="form-horizontal custom_frmHorizontal">
        <fieldset>

            <!-- Form Name -->
            <!-- Text input-->
            <div class="form-group">

                <div class="col-md-12">
                    @*@Html.HiddenFor(model => model.Subscription)*@
                    @Html.TextBoxFor(model => model.CompanyName, new { @class = "form-control input-md", @autocomplete = "off", @placeholder = "Company Name", @id = "txtName" })
                    @Html.ValidationMessageFor(model => model.CompanyName, null, new { @class = "text-danger" })
                    <span id="ern" class="field-validation-error text-danger" data-valmsg-for="CompanyName" data-valmsg-replace="true" style="display:none;"></span>
                </div>
            </div>
            <div class="form-group">
                @*<label class="col-md-4 control-label" for="textinput">Email Address :</label>*@
                <div class="col-md-12">
                    @*<input id="textinput" name="textinput" type="text" placeholder="Email Address" class="form-control input-md">*@

                    @Html.TextBoxFor(model => model.Email, new { @class = "form-control input-md", @style = "background-color:transparent !important;", @autocomplete = "off", @placeholder = "Email Address", @id = "txtemail" })
                    @Html.ValidationMessageFor(model => model.Email, null, new { @class = "text-danger" })
                    <span id="ere" class=" field-validation-error text-danger" data-valmsg-for="Email" data-valmsg-replace="true" style="display:none;"></span>
                </div>
            </div>
            <div class="form-group">
                <div class="col-md-12">

                    @Html.TextBoxFor(model => model.Mobile, new { @class = "form-control input-md", @autocomplete = "off", @placeholder = "Phone Number", @id = "txtMobile" })
                    @Html.ValidationMessageFor(model => model.Mobile, null, new { @class = "text-danger" })
                    <span id="ermob" class=" field-validation-error text-danger" style="display:none;"></span>
                </div>
            </div>
            <div class="form-group">
                <div class="col-md-12">

                    @Html.TextBoxFor(model => model.CRN, new { @class = "form-control input-md", @autocomplete = "off", @placeholder = "Company CRN", @id = "txtCrn" })
                    @Html.ValidationMessageFor(model => model.CRN, null, new { @class = "text-danger" })
                    <span id="ercrn" class=" field-validation-error text-danger" style="display:none;"></span>

                </div>
            </div>
            <div class="form-group">
                <div class="col-md-12">

                    @Html.TextBoxFor(model => model.EmpStrength, new { @class = "form-control", @autocomplete = "off", @placeholder = "Employees Strength", @id = "txtEmpStr" })
                    @Html.ValidationMessageFor(model => model.EmpStrength, null, new { @class = "text-danger" })
                    <span id="eremp" class="field-validation-error text-danger" style="display:none;"></span>
                </div>
            </div>
            <div class="form-group">
                <div class="col-md-12">

                    @Html.TextBoxFor(model => model.Address, new { @class = "form-control input-md", @autocomplete = "off", @placeholder = "Company Address", @id = "txtCadrs" })
                    @Html.ValidationMessageFor(model => model.Address, null, new { @class = "text-danger" })
                    <span id="eradrs" class="errmsg field-validation-error text-danger" style="display:none;"></span>
                </div>
            </div>
            <div class="form-group btn_wrap">
                <div class="col-md-12">
                        <button id="formSubmit" value="Submit" type="submit" class="btnCutom1 btn btn-primary">Send Request<i class="far fa-paper-plane pl-3"></i></button>
                </div>
            </div>
        </fieldset>
    </div>
}

jquery

$('#myForm').on('submit', function(event) {
  var frmData = $("myForm");
  event.preventDefault()

  var name = document.getElementById('txtName').value;
  var email = document.getElementById('txtemail').value;
  var mobile = document.getElementById('txtMobile').value;
  var crn = document.getElementById('txtCrn').value;
  var emp = document.getElementById('txtEmpStr').value;
  var adrs = document.getElementById('txtCadrs').value;

  if (name.length == 0) {
    //alert("Please insert Company Name");
    $("#ern").text("Company name must required").fadeIn();
  }
  if (email.length == 0) {
    $("#ere").text("Please insert email address").fadeIn();
  }
  if (mobile.length == 0) {
    //alert("Please insert Mobile Number");
    $("#ermob").text("Please insert Mobile Number").fadeIn();
  }
  if (crn.length == 0) {
    //alert("Please insert CRN");
    $("#ercrn").text("Please insert CRN").fadeIn();
  }
  if (emp.length == 0) {
    //alert("Please insert Employees");
    $("#eremp").text("Please insert Employees Strength").fadeIn();
  }
  if (adrs.length == 0) {
    //alert("Please insert Address");
    $("#eradrs").text("Please insert Company Address").fadeIn();
  } else {

    //var frmData = $("myForm");
    //e.preventDefault();
    $.ajax({
      type: "Post",
      ContentType: "application/json; charset=utf-8",
      data: "{frmData:" + JSON.stringify(frmData) + "}",
      // url: "pricing/Index",                   
      success: function(data) {
        alert("sent successfully:" + data);
        location.window.href = "RegUser/User";

      },
      error: function(result) {
        //$form = $(this);
        alert("something went wrong");
      }

    });
  }
});

控制器

public class UserController : Controller
{
    //
    // GET: /User/
    [HttpGet]
    public ActionResult RegUser(int id=0)
    {
        UserDtl userModel = new UserDtl();
        return View(userModel);
    }

    [HttpPost]
    public ActionResult RegUser(UserDtl userModel, string CompanyName, string Email, string CRN, string EmpStrength, string Mobile, string Address)
    {
        try
        {
            using (DbModels dbModel = new DbModels())
            {
                dbModel.UserDtls.Add(userModel);
                dbModel.SaveChanges();
            }
            if (ModelState.IsValid)
            {
                var senderemail = new MailAddress("shakil.7878@gmail.com", "deem-admin");
                var receiveremail = new MailAddress(Email, "New Request");
                var password = "inDia123#";
                var sub = CompanyName;
                string bodyText = string.Format("<table border='0' cellpadding='0' cellspacing='0' style='width:600px; background:#efefef;'> <tr><td colspan='2'><center><img src='https://drcoder1tcircle.000webhostapp.com/mh.jpg' /></center></td></tr><tr><td colspan='2'><center><img src='https://drcoder1tcircle.000webhostapp.com/ms.jpg' /></center></td></tr> <tr><td style='height:40px;'></td> <td style='height:40px;'></td></tr> <tr> <td style='color:#000000;text-align:right; font-family:Arial; font-size:12px;'><b>New Request</b></td><td> </td></tr> <tr><td style='color:#000000;text-align:right; font-family:Arial; font-size:12px;'>Company Name: </td> <td style='color:#000000;text-align:center; font-family:Arial; font-size:12px;'>{0}</td> </tr> <tr><td style='color:#000000;text-align:right; font-family:Arial; font-size:12px;'>Email Address: </td> <td style='color:#000000;text-align:center; font-family:Arial; font-size:12px;'>{1}</td> </tr> <tr> <td style='color:#000000;text-align:right; font-family:Arial; font-size:12px;'> Company Registration No.</td> <td style='color:#000000;text-align:center; font-family:Arial; font-size:12px;'>{2}</td> </tr> <tr> <td style='color:#000000;text-align:right; font-family:Arial; font-size:12px;'>Employees Strength</td> <td style='color:#000000;text-align:center; font-family:Arial; font-size:12px;'>{3}</td></tr> <tr><td style='color:#000000;text-align:right; font-family:Arial; font-size:12px;'> Mobile No.</td> <td style='color:#000000;text-align:center; font-family:Arial; font-size:12px;'>{4}</td></tr> <tr><td style='color:#000000;text-align:right; font-family:Arial; font-size:12px;'> Company Address</td>  <td style='color:#000000;text-align:center; font-family:Arial; font-size:12px;'>{5}</td> </tr>  <tr><td style='height:40px;'></td> <td style='height:40px;'></td></tr>  <tr><td style='background:#303030; height:30px;' colspan='2'><center><a style='color:#ffffff; text-align:center; font-family:Arial; font-size:12px;' href='#' target='_blank'>www.deem.sa</a></center></td></tr> </table>", CompanyName, Email, CRN, EmpStrength, Mobile, Address);
                var body = bodyText;                    
                var smtp = new SmtpClient
                    {Host = "smtp.gmail.com",
                    Port = 587,
                    EnableSsl = true,
                    DeliveryMethod = SmtpDeliveryMethod.Network,
                    UseDefaultCredentials = false,
                    Credentials = new NetworkCredential(senderemail.Address, password)};
                var mess = new MailMessage(senderemail, receiveremail)
                    {Subject = sub,
                    Body = body,
                    IsBodyHtml = true};                    
                smtp.Send(mess);
                ModelState.Clear();
                ViewBag.SuccessMessage = "Request sent Successful. We will send you Registration Details on your email address.";
                return View();
            }
            //ModelState.Clear();
            //ViewBag.SuccessMessage = "Request sent Successful. We will send you Registration Details on your email address.";            
        }
        catch (Exception ex)
        {
        }
        return View("RegUser", new UserDtl());
    }
}

【问题讨论】：

请宽恕并格式化您的代码。 :)

标签： sql .net ajax model-view-controller

【解决方案1】：

您不能像这样为输入元素指定 DOM id (@id = "txtName")。 id 由框架自动生成。如果您在浏览器中查看源代码，您将看到这些元素已使用 2 个 id 呈现。这是无效的 HTML，导致您的损坏。

这里有其他问题的公认答案，基本上说你可以大写@id 来解决这个问题（即@Id），但提供这些答案的用户不了解这些元素的属性是如何生成的，并且是只是观察一个 hack 的副作用，它实际上并不能保证在任何情况下都能正常工作，尽管它现在可能恰好在某些条件下在一些浏览器中工作。

相反，删除“@id=”的任何使用，并使用 @Html.IdFor() 帮助程序来确定分配的 ID。例如：

<script>
var myId = "@Html.IdFor(m => m.CompanyName)";
</script>

然后，您将使用此 Javascript 变量（例如 myId）代替您在其余代码中发明的 ID（“txtName”）。例如，您可以更改：

var name = document.getElementById('txtName').value;

到这里：

var name = document.getElementById(myId).value;

而且由于您使用的是 jQuery，因此您也可以这样表达：

var name = $("#" + myId).val();

然后生成的 HTML 将是有效的，您的表单将按预期发布。

【讨论】：

可能是因为你的变量赋值都被注释掉了？即 //var name = $("#" + myCn).val();

【解决方案2】：

$('#myForm').on('submit', function (event) {
    var frmData = $("myForm");
  //  event.preventDefault()

    var myCn = "@Html.IdFor(m => m.CompanyName)";
    var myEm = "@Html.IdFor(m => m.Email)";
    var myMo = "@Html.IdFor(m => m.Mobile)";
    var myCr = "@Html.IdFor(m => m.CRN)";
    var myEp = "@Html.IdFor(m => m.EmpStrength)";
    var myAd = "@Html.IdFor(m => m.Address)";

    var name = document.getElementById(myCn).value;
    var email = document.getElementById(myEm).value;
    var mobile = document.getElementById(myMo).value;
    var crn = document.getElementById(myCr).value;
    var emp = document.getElementById(myEp).value;
    var adrs = document.getElementById(myAd).value;

    //var name = $("#" + myCn).val();
    //var email = $("#" + myEm).val();
    //var mobile = $("#" + myMo).val();
    //var crn = $("#" + myCr).val();
    //var emp = $("#" + myEp).val();
    //var adrs = $("#" + myAd).val();


    if (name.length == 0) {
        //alert("Please insert Company Name");
        $("#ern").text("Company name must required").fadeIn();
    } if (email.length == 0) {
        $("#ere").text("Please insert email address").fadeIn();
    } if (mobile.length == 0) {
        //alert("Please insert Mobile Number");
        $("#ermob").text("Please insert Mobile Number").fadeIn();
    }
    if (crn.length == 0) {
        //alert("Please insert CRN");
        $("#ercrn").text("Please insert CRN").fadeIn();
    }
    if (emp.length == 0) {
        //alert("Please insert Employees");
        $("#eremp").text("Please insert Employees Strength").fadeIn();
    }
    if (adrs.length == 0) {
        //alert("Please insert Address");
        $("#eradrs").text("Please insert Company Address").fadeIn();
    }
    else {

        //var frmData = $("myForm");
        //e.preventDefault();
        $.ajax({
            type: "Post",
            ContentType: "application/json; charset=utf-8",
            data: "{frmData:" + JSON.stringify(frmData) + "}",
            // url: "pricing/Index",
            success: function (data) {
                alert("sent successfully:" + data);
                location.window.href = "RegUser/User";

            },
            error: function (result) {
                //$form = $(this);
                alert("something went wrong");
            }

        });
    }

});

【讨论】：