在 .NET MVC 中将数据从视图传递到控制器 - “@model”未突出显示

Question

以下代码可以按我的需要工作：

 @using (Html.BeginForm("LOLOL", "PATIENT", null))
    {
        @Html.ValidationSummary(true)
        <fieldset>
            <legend>PATIENT</legend>
            <div class="editor-label">
                @Html.LabelFor(model => model.Name)
            </div>
            <div class="editor-field">
                @Html.EditorFor(model => model.Name)
                @Html.ValidationMessageFor(model => model.Name)
            </div>

        </fieldset>
        <p>
            <input type="submit" value="SUBMIT" />
        </p>
    }  

在 LOLOLController 中：

[HttpPost]
    public IActionResult LOLOL(Patient p) {
        var client = new MongoClient("mongodb://localhost:27017");
        var userId = _userManager.GetUserId(HttpContext.User);
        string db_name = "test" + userId;
        var database = client.GetDatabase(db_name);
        var collection = database.GetCollection<BsonDocument>("patients");
        var filter = Builders<BsonDocument>.Filter.Eq("Name", p.Name.ToString());
        var document = collection.Find(filter).First();
        // I'm cutting short the rest of the code, because when I do something 
 // similar later, "collection.Find(filter).First()" fires an exception, I'll     
// explain..


        return View(p);
    }

我有一些相当于去掉 HTML 中的 fieldset 元素，基本上只在“Html.BeginForm”中留下一个按钮，但是数据显然没有正确绑定，我知道这是因为如果我只有一个按钮并且没有数据输入，我单击按钮，然后我收到一条错误消息，指出无法从数据库中找到数据。 （编辑：我现在已经确认这确实是因为 Patient 对象没有像我预期的那样传递给控制器​​，似乎是在调用 html.beginform 时创建了一个全新的 Patient 对象......我想也许旧的 Patient 对象正在被传递，所以每次我们使用 Html.BeginForm 时我都不必输入它的所有数据成员）

总而言之，我想填写一个文本框，单击一个按钮以加载新页面并显示该文本框的值，但该值也基本上保持在会话状态中，所以如果我调用另一个 Html.BeginForm 函数并进入第三个视图，第一个视图中的文本将显示在第三个视图中，即使我不必在第二个视图中键入它的值。 希望我可以重复这个过程，本质上是加载一个类的数据成员，每个数据成员有一个视图。

Answer 1

确保将数据从前一个视图传递到控制器的新视图。当您传递它时，将 @HiddenFor 包含在新视图中的前一个视图中的那些属性。这样，新视图将保留，然后将值传递给您的下一个 POST。

@Html.HiddenFor(model => model.PropertyYouPassedAndWantToKeepAndPassAgain

编辑：这里是为一个对象使用多个视图的逻辑......根据要求。

型号：

public class Patient
{
    string Name { get; set; }
    string Address { get; set; }
    string City { get; set; }
}

第 1 页获取：

[HttpGet]
public ActionResult Page1()
{
    Patient patient = new Patient();
    return View("~/Views/Page1.cshtml", patient);
}

第 1 页视图...仅询问名称。

@model mysite.Models.Patient

@using (Html.BeginForm("LOLOL", "PATIENT", null))
    {
        @Html.ValidationSummary(true)
        <fieldset>
            <legend>PATIENT</legend>
            <div class="editor-label">
                @Html.LabelFor(model => model.Name)
            </div>
            <div class="editor-field">
                @Html.EditorFor(model => model.Name)
                @Html.ValidationMessageFor(model => model.Name)
            </div>

        </fieldset>
        <p>
            <input type="submit" value="SUBMIT" />
        </p>
    }

Page1 POST...获取患者并将其传递到下一个视图...

[HttpPost]
public ActionResult Page1(Patient patient)
{
    if (ModelState.IsValid)
    {
        return View("~/Views/Page2.cshtml", patient); // pass your patient to the second page view with the name
    }
    else
    {
        return View("~/Views/Page1.cshtml", patient);
    }
}

Page2 GET... 从之前的 Page1 POST 中获取患者并将其发送到 Page2 视图。

[HttpGet]
public ActionResult Page2(Patient patient)
    {
        // Receive patient from Page1 post and pass it to new view... includes the name
        return View("~/Views/Page2.cshtml", patient);
    }

Page2 视图获取对象...使用 HiddenFor 保留您刚刚从 GET 发送的名称。

@model mysite.Models.Patient

@using (Html.BeginForm("LOLOL", "PATIENT", null))
{
    @Html.HiddenFor(model => model.Name) @* This will keep the name on your next post *@
    @Html.ValidationSummary(true)
    <fieldset>
        <legend>PATIENT</legend>
        <div class="editor-label">
            @Html.LabelFor(model => model.Address)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.Address)
            @Html.ValidationMessageFor(model => model.Address)
        </div>

    </fieldset>
    <p>
        <input type="submit" value="SUBMIT" />
    </p>
}

由于 HiddenFor 拥有名称，它将在您的下一篇文章中传递。它在那里，但对表单本身隐藏。

[HttpPost]
public ActionResult Page2(Patient patient)
{
    // Because of the HiddenFor, the Name will be passed because it was kept in the view... but hidden from the form itself.
    // It's basically storing it for you to pass again
    if (ModelState.IsValid)
    {
        // Pass object with Name and Address to next controller
        return View("~/Views/Page3.cshtml", patient);
    }
    else
    {
        return View("~/Views/Page2.cshtml", patient);
    }
}

第2页发布

[HttpPost]
public ActionResult Page2(Patient patient)
{
    // Because of the HiddenFor, the Name will be passed because it was kept in the view... but hidden from the form itself.
    // It's basically storing it for you to pass again
    if (ModelState.IsValid)
    {
        // Pass object with Name and Address to next controller
        return View("~/Views/Page3.cshtml", patient);
    }
    else
    {
        return View("~/Views/Page2.cshtml", patient);
    }
}

第3页获取

[HttpGet]
public ActionResult Page3(Patient patient)
{
    // Pass patient again... to your next view
    return View("~/Views/Page3.cshtml", patient);
}

第 3 页视图...

@using (Html.BeginForm("LOLOL", "PATIENT", null))
{
    @Html.HiddenFor(model => model.Name) @* Keep name again for your next post *@
    @Html.HiddenFor(model => model.Address) @* Now we are keeping the address as well *@
    @Html.ValidationSummary(true)
    <fieldset>
        <legend>PATIENT</legend>
        <div class="editor-label">
            @Html.LabelFor(model => model.City)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.City)
            @Html.ValidationMessageFor(model => model.City)
        </div>

    </fieldset>
    <p>
        <input type="submit" value="SUBMIT" />
    </p>
} 

依此类推……直到你的模型完成并想用它做点什么。