ASP Razor 页面 BindProperties 值在 Post 上丢失

Question

I 'm working with an ASP Razor project (.Net5). Thee is a page with the user list and a filter. The goal is to present the user that match the filtering criteria. The code below is able to do the filtering but the filtering values are lost (become blank) everytime the filtering is done.

I have [BindProperties] and I don;t understand why it works for the UserList (the table data) and not for the filter criteria.

I tried to reassign the values but it;s not working. Does anyone has an idea how to solve this? Any pointer to the underlying reason and documentation page would be appreciated. I have looked at https://www.learnrazorpages.com/razor-pages/tempdata but I'm not sure it's the way to go.

Also do not hesitate to give feedback on the code itself as it's literally my first ASP.Net project.

UserList.cshtml

@model Web.Areas.Admin.Pages.UserListModel
@{
    ViewData["Title"] = "User list";
}
<h1>User list</h1>

<div>
    <form method="post">
        <label asp-for="UserNameFilter"></label>
        <input type="text" name="UserNameFilter" /> @*This input criteria reset when I click on filter*@
        <input type="submit" value="Filter" />
    </form>
</div>

<table class="table">
    <thead>
        <tr>
            <th>Id</th>
            <th>User Name</th>
            <th>Email</th>
            <th>Password</th>
            <th>Actions</th>
        </tr>
    </thead>
    <tbody>
        @foreach (var user in Model.UserInfos)
        {
        <tr>
            <td>@user.Id</td>
            <td>@user.UserName</td>
            <td>@user.Email</td>
            <td>
                <a asp-page="/UserUpdate" asp-route-id="@user.Id">Edit</a> |
                <a asp-page="/Details" asp-route-id="@user.Id">Details</a> |
                <a asp-page="/UserDelete" asp-route-id="@user.Id">Delete</a>
            </td>
        </tr>
        }
    </tbody>
</table>

UserList.cshtml.cs

using System.Collections.Generic;
using System.Linq;
using Entities;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Services;

namespace Web.Areas.Admin.Pages
{
    [Authorize(Roles = "ADMIN")]
    [BindProperties]
    public class UserListModel : PageModel
    {
        public string UserNameFilter { get; set; }
        public List<UserInfo> UserInfos { get; set; }
        private readonly IUserService _userService;

        public UserListModel(IUserService userService)
        {
            _userService = userService;
        }

        public void OnGet()
        {
            UserInfos = _userService.GetUserInfoList(new UserInfoFilter()).ToList();
        }

        public void OnPost()
        {
            var userInfoFilter = new UserInfoFilter
            {
                UserName = UserNameFilter
            };
            UserInfos = _userService.GetUserInfoList(userInfoFilter).ToList();
        }
    }
}

Answer 1

So that was a basic answer... you need to assign the value of the input with the model...

<input type="text" name="UserNameFilter" value="@Model.UserNameFilter"/> 

I'm leaving the post and answer here for other noob like me in future. Keep coding..

Answer 2

The above code works. If someone else is looking for it, I want to add my scenario here.

I have two screens. One is sending an ID through asp-route-CurrentPOID

once on the other page, I was able to get it

[BindProeprty(SupportsGet = true)]
public int POID {get;set;}


public void onGet(int CurrentPOID)
{
   CurrentPOID = whatever was selected on the other page
   // so I want to assign route value to this pages POID
   CurrentPOID = POID;  //works (only for onGet)

   _context.BLLMETHOD(currentPOID)  //works
   OR
   _context.BLLMETHOD(POID)  //works
}

However, I was not getting POID once I did onPost POID was null

to solve this, I used exactly what the author of this post did

on front

<input type="hidden" name="POID" value="@Model.POID"/> 

This solved my issue on Post, where POID was null.

I am new to razor pages, so please pardon the inefficiency.