如何将参数值从DDL传递到过滤查询

Question

在尝试了各种方案后，我对如何最好地将下拉列表中的选定值传递回 .cs 中的查询感到困惑。我需要下拉列表的结果成为我的查询中的“官员”值（其中 (x.ProbOfficer == 官员），以便根据官员的姓名和 DateComplete 字段为空的任何记录来过滤报告。

这是.cs：

[BindProperties]

public class IndexModel : PageModel
{
    private readonly ApplicationDbContext _db;

    public IndexModel(ApplicationDbContext db)
    {
        _db = db;
    }

    public IEnumerable<Officer> DisplayProbOfficerData { get; set; }
    public IEnumerable<InvestigationLog> Results { get; set; }

    public async Task OnGetAsync()
    {
        await _db.Officer.Select(a => a.DisplayName).ToListAsync();
        DisplayProbOfficerData = await _db.Officer.ToListAsync();
        Results = _db.InvestigationLog.ToList();
    }

    public void OnPost(string officer)
    {
        Results = (from x in _db.InvestigationLog where (x.ProbOfficer == officer) && (x.DateComplete.ToString() == "") select x).ToList();

        var officer1 = officer;

        ViewData["officerparameter"] = $"For Officer: {officer1}";
    }

这是我的 .cshtml 的相关部分：

 <form asp-page="./Index" method="post">
     <div class="form-actions no-color">
         <p>
             <h5>Probation Officer Selection</h5>
             <br/>
             <select name="SelectOfficer" id="Select1" class="form-select" asp-items="@(new SelectList(Model.DisplayProbOfficerData.OrderBy(x => x.DisplayName),"DisplayName", "DisplayName"))"><option value="" selected disabled>---Select Probation Officer---</option></select>
             <br/>
             <input type="submit" value="Filter Report" class="btn btn-primary mx-2" />
             <a asp-page="./Index" class="btn btn-link mx-2">Return to Full List</a>
         </p>
     </div>

并尝试用 Javascript 来完成它，但知道这是错误的：

    <script language="javascript">
        {
            const dropdown = document.getElementById('SelectOfficer');
            dropdown.addEventListener('change', () => {
                (SelectOfficer => input.value = officer);
            });
        }

     </script>

任何帮助将不胜感激。我需要在周一之前完成这项工作，但我被困住了！

Answer 1

模型绑定系统通过

name

来绑定属性，无需使用 js 只需更改

name

属性，如下所示：

<select name="Officer" id="Select1" class="form-select" asp-items="@(new SelectList(Model.DisplayProbOfficerData.OrderBy(x => x.DisplayName),"DisplayName", "DisplayName"))"><option value="" selected disabled>---Select Probation Officer---</option></select>