Javascript 如果可选参数概念不适用'；不行？

我有一个JS函数，它根据选中的单选按钮从文本框中获取一个值

示例：如果选择了RadioButtonNo，则值从文本框A中提取，否则如果选择RadioButtonYes，则值从文本框B中提取。以下脚本在我看来

$('#btnVolunteerSaveBtn').on('click', function() { // on click of save button
  if (document.getElementById('RadioNo').checked) { //ID of radio button NO
    var checking = $('#Donation').val(); //ID of textbox from where the value is to be taken if RadioButton No is selected
    if (checking == "") {
      //if nothing is entered, stop from saving in DB
    } else {
      x = $('#Donation').val(); //ID of textbox from where the value is to be taken if RadioButton No is selected
      $.ajax({
        url: '@Url.Action("DonationValue","VolunteerInfo")',
        data: {
          name: x
        },
        type: "POST"
      });
    }
  } else {
    x = $('#GetNames').val(); //ID of textbox from where the value is to be taken if RadioButton Yes is selected
    $.ajax({
      url: '@Url.Action("DonationValue","VolunteerInfo")',
      data: {
        name: x
      },
      type: "POST"
    });
  }
});

到现在为止，它似乎工作得很好。现在谈到控制器，我有一个函数

DonationValue

我的问题：

[HttpPost]
public ActionResult AddVolunteer(VolunteerInfo viewModel)
{
    if (!ModelState.IsValid)
    {
        return View("AddVolunteer", viewModel);
    }

    var volunteer = new VolunteerInfo()
    {
        Name = viewModel.Name,
        BirthdayDateTime = viewModel.BirthdayDateTime,
        Address = viewModel.Address,
        PhoneNumber = viewModel.PhoneNumber,
        EmailAddress = viewModel.EmailAddress,
        OccasionsID = viewModel.OccasionsID,
        DonationForWhom = _DonationValue
    };

    if (!string.IsNullOrEmpty(volunteer.DonationForWhom))
    {
        _context.VolunteerInfos.Add(volunteer);
        _context.SaveChanges();
        return RedirectToAction("Index", "Home");
    }

    return //something to save state so that user doesnt have to enter all the values again
}

[HttpPost]
public void DonationValue(string name)
{
    _DonationValue = name;
}

如何传递上面的

name

参数

如果id为捐赠的文本框中没有填写任何内容，我如何停止 在数据库中保存表单

我的尝试：

[HttpPost]
public ActionResult AddVolunteer(VolunteerInfo viewModel)
{
    if (!ModelState.IsValid)
    {
        return View("AddVolunteer", viewModel);
    }

    var volunteer = new VolunteerInfo()
    {
        Name = viewModel.Name,
        BirthdayDateTime = viewModel.BirthdayDateTime,
        Address = viewModel.Address,
        PhoneNumber = viewModel.PhoneNumber,
        EmailAddress = viewModel.EmailAddress,
        OccasionsID = viewModel.OccasionsID,
        DonationForWhom = _DonationValue
    };

    if (!string.IsNullOrEmpty(volunteer.DonationForWhom))
    {
        _context.VolunteerInfos.Add(volunteer);
        _context.SaveChanges();
        return RedirectToAction("Index", "Home");
    }

    return //something to save state so that user doesnt have to enter all the values again
}

[HttpPost]
public void DonationValue(string name)
{
    _DonationValue = name;
}

我试过了

public string DonationValue(string name = null)
{
    return name; //Trying to pass this value above
}

这没用。它解决了错误，但传递的值始终为null。我也尝试了一些其他的方法，但都没有效果

编辑：

[HttpPost]
public ActionResult AddVolunteer(VolunteerInfo viewModel)
{
    if (!ModelState.IsValid)
    {
        return View("AddVolunteer", viewModel);
    }

    var volunteer = new VolunteerInfo()
    {
        Name = viewModel.Name,
        BirthdayDateTime = viewModel.BirthdayDateTime,
        Address = viewModel.Address,
        PhoneNumber = viewModel.PhoneNumber,
        EmailAddress = viewModel.EmailAddress,
        OccasionsID = viewModel.OccasionsID,
        DonationForWhom = _DonationValue
    };

    if (!string.IsNullOrEmpty(volunteer.DonationForWhom))
    {
        _context.VolunteerInfos.Add(volunteer);
        _context.SaveChanges();
        return RedirectToAction("Index", "Home");
    }

    return //something to save state so that user doesnt have to enter all the values again
}

[HttpPost]
public void DonationValue(string name)
{
    _DonationValue = name;
}

@戴西·希普顿。 这是更好的解决方案吗

<script>
        $(function() {
            $('#btnVolunteerSaveBtn').on('click', function() { // on click of save button
                debugger;
                if (document.getElementById('RadioNo').checked) { //ID of radio button NO
                    var checking = $('#Donation').val(); //ID of textbox from where the value is to be taken if RadioButton No is selected
                    if (checking == "") {
                        //if nothing is entered, stop from saving in DB
                    }
                    else {
                        var x = $('#Donation').val(); //ID of textbox from where the value is to be taken if RadioButton No is selected
                        var jsonObject = {
                            "textValue": x,
                            "isRadioSelected": "true" // show the radio is selected
                        };

                        $.ajax({
                            url: '@Url.Action("AddVolunteer", "VolunteerInfo")',
                            data: JSON.stringify(jsonObject),
                            contentType: "application/json; charset=utf-8",
                            dataType: "json",
                            type: "POST",
                            error: function (response) {
                                alert(response.responseText);
                            },
                            success: function (response) {
                                alert(response);
                            }
                        });
                    }
                }
                else {
                    var jsonObject2 = {
                        "textValue": $('#GetNames').val(),
                        "isRadioSelected": "false" // show the radio is not selected
                    };

                    $.ajax({
                        url: '@Url.Action("AddVolunteer", "VolunteerInfo")',
                        data: JSON.stringify(jsonObject2),
                        contentType: "application/json; charset=utf-8",
                        dataType: "json",
                        type: "POST",
                        error: function (response) {
                            alert(response.responseText);
                        },
                        success: function (response) {
                            alert(response);
                        }
                    });
                }

            });
        })
    </script>

1） 客户端使用name参数调用

DonationValue

post方法

e、 g.

name=“abc”

此返回值将存储在客户端say变量

retunedDonationValue

如果您没有传递任何name参数，那么上面的post方法将返回空字符串，然后只需设置

retunedDonationValue=''

2） 现在，您必须将上面的

retunedDonationValue

传递给post json对象中的post方法，如

var jsonObject = 
                {
                    "Name" = "YourName",
                    "BirthdayDateTime" = "YourBirthdayDateTime",
                    "Address" = "YourAddress",
                    "PhoneNumber" = "YourPhoneNumber",
                    "EmailAddress" = "YourEmailAddress",
                    "OccasionsID" = "YourOccasionsID",
                    "DonationForWhom" = retunedDonationValue  //Note here
                }

3） 并将此post数据传递给http调用AddInvorite

                    $.ajax({
                        url: '@Url.Action("AddVolunteer", "VolunteerInfo")',
                        data: JSON.stringify(jsonObject),
                        contentType: "application/json; charset=utf-8",
                        dataType: "json",
                        type: "POST",
                        error: function (response) {
                            alert(response.responseText);
                        },
                        success: function (response) {
                            alert(response);
                        }
                    });

4） 你的行动方法是

[HttpPost]
    public ActionResult AddVolunteer(VolunteerInfo viewModel)
    {
        if (!ModelState.IsValid)
        {
            return View("AddVolunteer", viewModel);
        }

        var volunteer = new VolunteerInfo()
        {
            Name = viewModel.Name,
            BirthdayDateTime = viewModel.BirthdayDateTime,
            Address = viewModel.Address,
            PhoneNumber = viewModel.PhoneNumber,
            EmailAddress = viewModel.EmailAddress,
            OccasionsID = viewModel.OccasionsID,
            DonationForWhom = viewModel.DonationForWhom
        };

        if (!string.IsNullOrEmpty(volunteer.DonationForWhom))
        {
            _context.VolunteerInfos.Add(volunteer);
            _context.SaveChanges();
        }

        return View(viewModel);

    }

---

您忘记将

[HttpPost]

属性放在您的

DonationValue

method@RuiJarimba：没有。我试过了。不起作用。@Priyanka Dembla，上面代码中的

ha

参数在哪里？@ershoaib:我是说name参数。现在请看。谢谢你纠正我，@Priyanka Dembla，你是否检查了

如果（！string.IsNullOrEmpty（志愿者.donationforwhere））{{u context.志愿者信息.Add（志愿者）；_context.SaveChanges（）}

你的解决方案有什么变化，查看我新发布的解决方案可能会有帮助：）@Priyanka Dembla，让我知道它是否对你有帮助：）