完善控制器

为HomeController注入SearchService实例，给Index动作添加视图模型参数，并调用SearchService的GetList方法，最后将视图模型返回给视图。

代码如下：

public class HomeController(SearchService searchService) : Controller
{
    public IActionResult Index(SearchViewModel model)
    {
        return View(searchService.GetList(model));
    }
}

设置模型和标题

@model SearchViewModel
@{
    ViewBag.Title = "首页";
}

添加查询部分

<form method="post">
    <div class="field is-grouped">
        <div class="field has-addons">
            <div class="control">
                <a class="button is-static">专业</a>
            </div>
            <div class="control">
                <div class="select">
                    <select asp-for=MajorId asp-items=Model.Majors
                            hx-get="/Student/GetClassSelectPartial"
                            hx-target="#ClassId"
                            hx-include="#GradeId,#ClassId"
                            hx-swap="outerHTML">
                        <option value="">请选择</option>
                    </select>
                </div>
            </div>
        </div>
        <div class="field has-addons">
            <div class="control">
                <a class="button is-static">年级</a>
            </div>
            <div class="control">
                <div class="select">
                    <select asp-for=GradeId asp-items=Model.Grades
                            hx-get="/Student/GetClassSelectPartial"
                            hx-target="#ClassId"
                            hx-include="#MajorId,#ClassId"
                            hx-swap="outerHTML">
                        <option value="">请选择</option>
                    </select>
                </div>
            </div>
        </div>
        <div class="field has-addons">
            <div class="control">
                <a class="button is-static">班级</a>
            </div>
            <div class="control">
                <div class="select">
                    <input asp-for="ClassId"
                           hx-get="/Student/GetClassSelectPartial"
                           hx-trigger="load"
                           hx-include="#MajorId,#GradeId"
                           hx-swap="outerHTML">
                </div>

            </div>
        </div>
        <div class="field has-addons">
            <div class="control">
                <a class="button is-static">性别</a>
            </div>
            <div class="control">
                <div class="select">
                    <select asp-for=Gender>
                        <option value="">请选择</option>
                        <option value="false">男</option>
                        <option value="true">女</option>
                    </select>
                </div>
            </div>
        </div>
        <div class="field has-addons">
            <div class="control">
                <a class="button is-static">姓名</a>
            </div>
            <div class="control">
                <input asp-for=Name class="input">
            </div>
        </div>
        <div class="field has-addons">
            <div class="control">
                <a class="button is-static">学号</a>
            </div>
            <div class="control">
                <input asp-for=Number class="input">
            </div>
        </div>
        <div class="field">
            <button class="button is-primary">查找</button>
        </div>
    </div>
</form>

可以看到Major，Grade，Class的下拉栏请求的地址均是**/Student/GetClassSelectPartial**。

查询结果列表

<table class="table is-bordered is-striped is-hoverable is-fullwidth">
    <thead>
        <tr>
            <th>学号</th>
            <th>姓名</th>
            <th>专业</th>
            <th>年级</th>
            <th>班级</th>
            <th>性别</th>
            <th>生日</th>
        </tr>
    </thead>
    <tbody>
        @foreach (var result in Model.Results)
        {
            <tr>
                <td>@result.Number</td>
                <td>@result.Name</td>
                <td>@result.MajorName</td>
                <td>@result.GradeName</td>
                <td>@result.ClassName</td>
                <td>@(result.Gender?"女":"男")</td>
                <td>@result.Birthday.ToString("yyyy年MM月dd日")</td>
            </tr>
        }
    </tbody>
</table>

通过Results可以获得数据列表。

为什么只需要1个Action就能完成此操作？之前不是需要一个post请求吗？

因为如果不指定请求类型，Action能接受所有请求类型，包括get请求和post请求。

当我们通过浏览器直接进入首页，发送的是get请求，此时查询数据为空，因此可以显示所有数据。

而当我们点击按钮去筛选时，发送的是post请求，此时会根据条件查询数据。