本文介绍了发行保存编辑后的数据:DDL值不能为空的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

我有保存编辑的字段在我的MVC项目的问题。当我点击提交按钮,我得到一个错误

I am having an issue with saving the edited fields in my MVC project. When I click the submit button I get an error

值不能为空。
参数名:项目
  说明:执行当前Web请求的执行过程中发生未处理的异常。请查看有关错误的详细信息的堆栈跟踪以及它起源于code。

Value cannot be null.Parameter name: items Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

异常详细信息:System.ArgumentNullException:值不能为空。
参数名称:项目

Exception Details: System.ArgumentNullException: Value cannot be null.Parameter name: items

源错误:

63号线:
64号线:
65号线:@ Html.DropDownListFor(型号=> model.EventTypeID,新的SelectList(ViewBag.EventTypes,EventTypeID,EventType1),选择)
66号线:
第67行:

Line 63:Line 64:Line 65: @Html.DropDownListFor(model => model.EventTypeID, new SelectList(ViewBag.EventTypes, "EventTypeID", "EventType1"), "Choose")Line 66:Line 67:

我尝试过的一些事情,我已经看到了互联网上,但它似乎并没有为我做任何事情:(帮助将AP preciated谢谢!

I have tried some things that I have seen on the internet but it doesn't seem to be doing anything for me :( Help would be appreciated thank you!

这是我的控制器当我把一个破发点这里从来没有触发。

this is my controller When I put a break point here it never triggers.

    [HttpPost]
    public ActionResult IndexPST(Event_Setup es)
    {
        db.Event_Setup.Add(es);
        db.SaveChanges();
       return View("Index",es);
    }

这是我的看法。

@model DixonGroupInc.Models.Event_Setup

<link href="~/Content/EventManagement.css" rel="stylesheet" />

@using (Html.BeginForm("IndexPST", "EventManagement", FormMethod.Post))
 {
    @Html.AntiForgeryToken()
    @Html.ValidationSummary(true)

<div id="cntr">
    <div id="emLoc">
        <table id="ldTbl">
            <thead>
                <tr>
                    <th class="ln">
                        <img src="~/Images/4.gif" />
                    </th>
                    <th>
                        <img src="~/Images/5.gif" />
                    </th>
                    <th>
                        <img src="~/Images/5.gif" />
                    </th>
                    <th>
                        <img src="~/Images/5.gif" />
                    </th>
                    <th>
                        <img src="~/Images/5.gif" />
                    </th>
                </tr>
            </thead>
            <tbody>
                <tr>
                    <td class="chosen space">EventMetadata
                    </td>
                    <td class="space">Client / Vendor
                    </td>
                    <td class="space">Venu info
                    </td>
                    <td class="space">Sponsored Participants
                    </td>
                    <td class="space">Event Services
                    </td>
                </tr>
            </tbody>

        </table>
    </div>

    <div id="emSetup">
        Setup Meeting
    </div>

    <div id="emTable">
        <table class="myTbl">
            <tr>
                <td class="lblEvent clm1">
                    @Html.Label("Event Type")
                </td>
                <td class="clm2">
                    @Html.DropDownListFor(model => model.EventTypeID, new SelectList(ViewBag.EventTypes, "EventTypeID", "EventType1"), "Choose")
                </td>
                <td class="clm3">
                    @{Html.RenderAction("EventType", "EventManagement");}
                </td>
            </tr>
            <tr class="rows">
                <td class="lblEvent clm1">
                    @Html.Label("Event Title")
                </td>
                <td class="clm2">
                    @Html.EditorFor(model => model.EventTitle)
                    @Html.ValidationMessageFor(model => model.EventTitle)
                </td>
            </tr>
            <tr>
                <td class="lblEvent clm1">
                    @Html.Label("Event Identifier")
                </td>
                <td class="clm2">
                    @Html.EditorFor(model => model.EventIdentifier)
                    @Html.ValidationMessageFor(model => model.EventIdentifier)
                </td>
            </tr>
        </table>

        <table class="dateTbl">
            <tr class="rows">
                <td class="lblEvent clm1">
                    @Html.Label("Event Date From")
                </td>
                <td class="clm2">
                    @Html.TextBoxFor(model => model.EventDateFrom, new { @class = "dateFrom" })
                    @Html.ValidationMessageFor(model => model.EventDateFrom)
                </td>
                <td class="lblEvent">
                    @Html.Label("To")
                </td>
                <td class="clm4">
                    @Html.TextBoxFor(model => model.EventDateTo, new { @class = "dateTo" })
                    @Html.ValidationMessageFor(model => model.EventDateTo)
                </td>
            </tr>
        </table>

        <table class="myTbl">
            <tr>
                <td class="lblEvent clm1">
                    @Html.Label("Event Description")
                </td>
                <td class="clm2">
                    @Html.TextAreaFor(model => model.EventDescription, new
            {
                id = "taED"
            })
                    <div>
                        <span id="charLeft2"></span>characters remaining.
                    </div>

                    @Html.ValidationMessageFor(model => model.EventDescription)
                </td>
            </tr>
            <tr class="rows">
                <td class="lblEvent clm1">
                    @Html.Label("Custom Message")
                </td>
                <td class="clm2">
                    @Html.TextAreaFor(model => model.CustomMessage, new
            {
                id = "taCM"
            })
                    <div>
                        <span id="charLeft1"></span>characters remaining.
                    </div>

                    @Html.ValidationMessageFor(model => model.CustomMessage)
                </td>
            </tr>
            <tr>
                <td class="lblEvent clm1">
                    @Html.Label("Instructions")
                </td>
                <td class="clm2">
                    @Html.TextAreaFor(model => model.Instructions, new
            {
                id = "taInstrct"
            })
                    <div>
                        <span id="charLeft"></span>characters remaining.
                    </div>

                    @Html.ValidationMessageFor(model => model.Instructions)
                </td>
            </tr>
        </table>

        <table class="myTbl">
            <tr class="rows">
                <td>
                    @{Html.RenderAction("AddTrack", "EventManagement");}
                </td>
            </tr>
            <tr>
                <td>
                    @{Html.RenderAction("EventTrack", "EventManagement");}
                </td>
            </tr>
        </table>

        <table class="myTbl">
            <tr class="rows">
                <td class="lblEvent clm1">
                    @Html.Label("CFP Pocess")
                </td>
                <td class="clm2">
                    @Html.RadioButtonFor(model => model.CFPRequired, "true") Yes
                </td>
                <td class="clm3">
                    @Html.RadioButtonFor(model => model.CFPRequired, "false") No
                </td>
            </tr>
        </table>
    </div>

    <div id="emSubmit">

        <input type="submit" value="Save & Next" id="submit" />

    </div>
</div>

}

推荐答案

Viewbag可能不可靠所以一般不建议通过您的下拉通过viewbag列表数据。我建议将其添加到您的视图模型来代替。在你Event_Setup类请确保您有

Viewbag can be unreliable so generally it isn't recommended to pass your drop down list data through the viewbag. I would recommend adding it to your view model instead. In your Event_Setup class make sure that you have

public int EventTypeID { get; set; }

public List<SelectListItem> EventTypeList { get; set; }

您的控制器上让你可以设置EventTypeID设置的下拉默认下来,你的控制器应该有类似

on your controller get you can set EventTypeID to set a default on the drop down so your controller should have something like

Event_Setup es = new Event_Setup();
es.EventTypeID = //default value if you want;
es.EventTypeList = //Method call here where List<SelectListItem> is returned with your event list

然后在您的视图中,可以改变你的下拉菜单

then on your view you can change your drop down to

@Html.DropDownListFor(x => x.EventTypeID, Model.EventTypeList)

这篇关于发行保存编辑后的数据:DDL值不能为空的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!

08-24 09:05