C# Asp.Net MVC4 显示复选框列表

Asp.Net MVC4 Display CheckboxList

提问by Idrees Khan

I have searched a lot and spend 3 days only for searching and trying different technique (on stackoverflow etc) but I find no solution for implementing checkboxlist in asp.net mvc. And at last I am posting my problem to stackoverflow;
So, my model looks like this;

我搜索了很多东西，只花了 3 天时间来搜索和尝试不同的技术（在 stackoverflow 等上），但我没有找到在 asp.net mvc 中实现复选框列表的解决方案。最后我将我的问题发布到 stackoverflow；
所以，我的模型看起来像这样；

Many to Many relationship of my model(1 category may contain many projects and a project may belongs to many categories)
My controller;

我的模型的多对多关系（1个类别可能包含多个项目，一个项目可能属于多个类别）
我的控制器；

 [HttpGet]
    [Authorize(Roles = "Admin")]
    public ActionResult ProjectAdd()
    {
        return View();
    }

My view;

我的看法;

@using (Html.BeginForm())
{
    @Html.ValidationSummary(true)

    <fieldset>
        <legend>Add New Project</legend>

        <div class="editor-label">
            @Html.LabelFor(model => model.ProjectHeading)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.ProjectHeading)
            @Html.ValidationMessageFor(model => model.ProjectHeading)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.ProjecctUrl)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.ProjecctUrl)
            @Html.ValidationMessageFor(model => model.ProjecctUrl)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.ProjectLongDescription)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.ProjectLongDescription)
            @Html.ValidationMessageFor(model => model.ProjectLongDescription)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.PromoFront)
        </div>
        @Html.EditorFor(model => model.PromoFront)
        @Html.ValidationMessageFor(model => model.PromoFront)

        <div class="editor-label">
            @Html.LabelFor(model => model.ProjectThubmnail)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.ProjectThubmnail)
            @Html.ValidationMessageFor(model => model.ProjectThubmnail)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.ProjectImage)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.ProjectImage)
            @Html.ValidationMessageFor(model => model.ProjectImage)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.CategoryId)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.CategoryId)
            @Html.ValidationMessageFor(model => model.CategoryId)
        </div>

        <p>
            <input type="submit" value="Create" class="submit" />
        </p>

So, my question is How do I display checkboxlist for categories in my view?
How do I get selected values from that checkboxlist?

所以，我的问题是如何在我的视图中显示类别的复选框列表？
如何从该复选框列表中获取选定的值？

采纳答案by balexandre

You need to have an object that will have a list of all categories, for example, you could do this:

您需要有一个包含所有类别列表的对象，例如，您可以这样做：

[HttpGet]
[Authorize(Roles = "Admin")]
public ActionResult ProjectAdd()
{
    // Get all categories and pass it into the View
    ViewBag.Categories = db.ListAllCategories();

    return View();
}

in the top of your View

在您的视图顶部

@model Database.Project
@{
   // retrieve the list of Categories
   List<Database.Category> categories = ViewBag.Categories;
}

and then replace this

然后替换这个

    <div class="editor-label">
        @Html.LabelFor(model => model.CategoryId)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.CategoryId)
        @Html.ValidationMessageFor(model => model.CategoryId)
    </div>

for this

为了这

    <div class="editor-label">
        <label for="categories">Categories</label>
    </div>
    <div class="editor-field">
        @foreach(var c in categories) {

        <label class="checkbox">
            <input type="checkbox" name="categories" value="@c.CategoryId"> @c.CategoryName
        </label>

        }
    </div>

back in your Controller

回到你的控制器

[HttpPost]
[Authorize(Roles = "Admin")]
public ActionResult ProjectAdd(Database.Project model, int[] categories)
{
    if(ModelState.IsValid) {

        // fill up categories
        db.InsertAndSaveProject(model, categories);

    }

    ...

    return redirectToView("ProjectAdd");
}

回答by Rohit

Answer suggested by @balexandre above works great. However, I used following HTML Extension for CheckBoxList.

上面@balexandre 建议的答案效果很好。但是，我为 CheckBoxList 使用了以下 HTML 扩展。

1. CheckboxList in ASP.net MVC4
2. Source Code:HTML Extension Helper method (Github)

1. ASP.net MVC4 中的 CheckboxList
2. 源代码：HTML 扩展助手方法 (Github)

The Major advantage of using this helper method is clean code and better readability. E.g.

使用这个辅助方法的主要优点是干净的代码和更好的可读性。例如

@Html.CheckBoxListFor(model => model.SelectedItems, Model.AllItems)