如何将List 从Table传递给Controller？

I have this code in C# using EF Core 1.2 where I have a form containing two submit buttons. The first button 'upload' invokes my method 'UpLoadMyFile' which compares each line from my textarea to a pattern and returns a string which tells me if it matches one pattern. Then I add all my text and its states into a

我在使用EF Core 1.2的C#中有这个代码,我有一个包含两个提交按钮的表单。第一个按钮'upload'调用我的方法'UpLoadMyFile',它将我的textarea中的每一行与一个模式进行比较,并返回一个字符串,告诉我它是否与一个模式匹配。然后我将所有文本及其状态添加到一个

 List <Tuple<string, string>>

that I pass to my View via a ViewModel and display each line plus its state in a table.

我通过ViewModel传递给我的View并在表格中显示每一行及其状态。

Now I'm trying to save each line into my database when I click my second button 'save'. But every time I try to save my lines a NullReferenceException occurs which tells me my List from my table is null.

现在,当我点击第二个按钮“保存”时,我正试图将每一行保存到我的数据库中。但是每次我尝试保存我的行时都会发生NullReferenceException,告诉我我的表中的List是null。

I would like to know how to pass all lines and states from my Table 'MyTupleList' to my Post Method since I really don't know how to fix my problem.

我想知道如何将我的表'MyTupleList'中的所有行和状态传递给我的Post方法,因为我真的不知道如何解决我的问题。

My View:

@model Models.ViewModels.CreateSaetzeModelView
<form asp-action="ProcessCreateLines" asp-controller="SoftwareService" method="post" enctype="multipart/form-data">

<div class="div-marginBottom">        
    <table class="table">           
        <tbody>
            <tr>
                <td>
                    <textarea name="ExpressionTextarea" id="ExpressionTextarea" runat="server" TextMode="MultiLine" asp-for="@Model.LoadExpressions"></textarea>

                    <div class="col-md-10">
                        <input type="submit" name="upload" value="upload" /> !--Calls 'uploadmyfile' action-->
                    </div>
                </td>
                <td></td>
            </tr>
        </tbody>
    </table>
</div>
<br />
<div class="div-ExpressionEingabe">

</div>
@if (Model.MyLinesList != null)
{
    <div class="div-marginBottom">
        <table id="MyTupleList" class="table table_align">
            <thead>
                <tr>
                    <th>
                        State
                    </th>
                    <th>
                        MyLines
                    </th>
                </tr>
            </thead>
            <tbody>   

                    @foreach (var item in Model.MyLinesList)
                {
                    <tr>
                        <td>                               
                            @Html.DisplayFor(modelItem => item.Item2)
                        </td>
                        <td>
                            @Html.DisplayFor(modelItem => item.Item1)                            
                    </tr>
                }

            </tbody>
        </table>
        <input type="submit" name="save" value="save" />
    </div>
}

My Code:

    [HttpPost]
    [ValidateAntiForgeryToken]
    public async Task<IActionResult> ProcessCreateLines(string upload, string save, CreateLinesModelView cmv)
    {           
        //Button 'upload': Checking my lines 
        if (!string.IsNullOrEmpty(upload))
        {
            string expressions = Request.Form["ExpressionTextarea"].ToString();

            List<Tuple<string, string>> result = new FileUploadController().CheckExpressions(expressions);

            cmv.MyLinesList = result;

            return View("ProcessCreateLines", cmv);

        }

        //Button 'save': Saving my lines into a Database
        if (!string.IsNullOrEmpty(save))
        {
    // ****************************MyLinesList is null*******************
            var list = cmv.MyLinesList;

            ...saving my list into database...
            }

        }

1 个解决方案

#1

I managed to solve my problem thanks to the comment of @StephenMuecke by using instead of a Tupel a selfmade class

由于@StephenMuecke的评论使用而不是使用Tupel自制类,我设法解决了我的问题

public class MyListModel
{
    public string myLine { get; set; }
    public string myState { get; set; }
}
}

and creating a List out of it in my ViewModel

并在我的ViewModel中创建一个List

public List<MyListModel> LineWithState { get; set; }

Also in my View I replaced the foreach loop with a for loop

同样在我的视图中,我用for循环替换了foreach循环

@for (int i = 0; i < Model.LineWithState.Count; i++)
                {
                    <tr>
                        <td>
                            @Html.TextBoxFor(m=>m.LineWithState[i].myState)
                        </td>
                        <td>
                            @Html.TextBoxFor(m=>m.LineWithState[i].myLine)
                    </tr>

                }

#1