在 dot net core razor 页面中 - 你如何默认创建页面上的下拉选项？

Question

我目前的父页面可以正确导航到不同的子页面。子页面有子记录的站立网格 - 它还有 'Create' link 添加新的子记录。

在标准 Entity Framework 脚手架下，'Create' 页面具有标准 html“下拉”列表，用于 link 编辑为 'lookup' 值的字段。

下面是一些屏幕截图：

职位详情 link 导航到子记录：

新建 Link 打开标准的脚手架创建页面：

PositionId 字段显示父查找的完整选项列表 - 而不是引入父键默认值。

这是创建页面的代码：

对于创建页面 我的问题是 - 如何将 PositionID/PositionNbr 的值默认为前一个网格页面上所有现有子记录的值？ 这应该是一个标准的子记录创建场景——其中预填充了父键

我没有在 google 搜索中找到很多关于如何在子记录中预填充父外键的好例子 - 特别是当创建是在单独的创建页面上时。

希望我的问题有意义-提前致谢...

已修改-这里是代码原样

    using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Microsoft.AspNetCore.Mvc.Rendering;
using ThePositionerRazor2.Models;

namespace ThePositionerRazor2.Pages.PositionDetail
{
    public class CreateModel : PageModel
    {
        private readonly ThePositionerRazor2.Models.WorkManagerV4Context _context;

        public CreateModel(ThePositionerRazor2.Models.WorkManagerV4Context context)
        {
            _context = context;
        }

        public IActionResult OnGet()
        {
        ViewData["ImportanceId"] = new SelectList(_context.Imp, "ImportanceId", "ImportanceId");
        ViewData["Knowdepth"] = new SelectList(_context.Knowdep, "DepthId", "DepthId");
        ViewData["PositionId"] = new SelectList(_context.Possummary, "PositionId", "PositionNbr");
        ViewData["TimeSpent"] = new SelectList(_context.Timescale, "TimevalId", "TimevalId");
        ViewData["Workitem"] = new SelectList(_context.Workhier, "Workitemid", "Workitemid");
            return Page();
        }

        [BindProperty]
        public Posdetail Posdetail { get; set; }

        // To protect from overposting attacks, enable the specific properties you want to bind to, for
        // more details, see https://aka.ms/RazorPagesCRUD.
        public async Task<IActionResult> OnPostAsync()
        {
            if (!ModelState.IsValid)
            {
                return Page();
            }

            _context.Posdetail.Add(Posdetail);
            await _context.SaveChangesAsync();

            return RedirectToPage("./Index");
        }
    }
}

和

    @page
@model ThePositionerRazor2.Pages.PositionDetail.CreateModel

@{
    ViewData["Title"] = "Create";
}

<h1>Create</h1>

<h4>Posdetail</h4>
<hr />
<div class="row">
    <div class="col-md-4">
        <form method="post">
            <div asp-validation-summary="ModelOnly" class="text-danger"></div>
            <div class="form-group">
                <label asp-for="Posdetail.PositionId" class="control-label"></label>
                <select asp-for="Posdetail.PositionId" class ="form-control" asp-items="ViewBag.PositionId"></select>
            </div>
            <div class="form-group">
                <label asp-for="Posdetail.Workitem" class="control-label"></label>
                <select asp-for="Posdetail.Workitem" class ="form-control" asp-items="ViewBag.Workitem"></select>
            </div>
            <div class="form-group">
                <label asp-for="Posdetail.TimeSpent" class="control-label"></label>
                <select asp-for="Posdetail.TimeSpent" class ="form-control" asp-items="ViewBag.TimeSpent"></select>
            </div>
            <div class="form-group">
                <label asp-for="Posdetail.ImportanceId" class="control-label"></label>
                <select asp-for="Posdetail.ImportanceId" class ="form-control" asp-items="ViewBag.ImportanceId"></select>
            </div>
            <div class="form-group">
                <label asp-for="Posdetail.TimeNrmz" class="control-label"></label>
                <input asp-for="Posdetail.TimeNrmz" class="form-control" />
                <span asp-validation-for="Posdetail.TimeNrmz" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Posdetail.Knowdepth" class="control-label"></label>
                <select asp-for="Posdetail.Knowdepth" class ="form-control" asp-items="ViewBag.Knowdepth"></select>
            </div>
            <div class="form-group">
                <label asp-for="Posdetail.Need" class="control-label"></label>
                <input asp-for="Posdetail.Need" class="form-control" />
                <span asp-validation-for="Posdetail.Need" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Posdetail.TimeCalc" class="control-label"></label>
                <input asp-for="Posdetail.TimeCalc" class="form-control" />
                <span asp-validation-for="Posdetail.TimeCalc" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Posdetail.Postskval" class="control-label"></label>
                <input asp-for="Posdetail.Postskval" class="form-control" />
                <span asp-validation-for="Posdetail.Postskval" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Posdetail.Ftetime" class="control-label"></label>
                <input asp-for="Posdetail.Ftetime" class="form-control" />
                <span asp-validation-for="Posdetail.Ftetime" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Posdetail.Ftesal" class="control-label"></label>
                <input asp-for="Posdetail.Ftesal" class="form-control" />
                <span asp-validation-for="Posdetail.Ftesal" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Posdetail.Lastupdated" class="control-label"></label>
                <input asp-for="Posdetail.Lastupdated" class="form-control" />
                <span asp-validation-for="Posdetail.Lastupdated" class="text-danger"></span>
            </div>
            <div class="form-group">
                <input type="submit" value="Create" class="btn btn-primary" />
            </div>
        </form>
    </div>
</div>

<div>
    <a asp-page="Index">Back to List</a>
</div>

@section Scripts {
    @{await Html.RenderPartialAsync("_ValidationScriptsPartial");}
}

附加信息：

相关机型

    using System;
using System.Collections.Generic;

namespace ThePositionerRazor2.Models
{
    public partial class Possummary
    {
        public Possummary()
        {
            Posdetail = new HashSet<Posdetail>();
        }

        public int PositionId { get; set; }
        public string PositionNbr { get; set; }
        public string WorkTitle { get; set; }
        public string Purpose { get; set; }
        public double? JobValue { get; set; }
        public double? TimeTotal { get; set; }
        public double? Fte { get; set; }
        public double? Salary { get; set; }
        public DateTime? Lastupdated { get; set; }
        public string JobFamily { get; set; }
        public int? DescriptionTypeId { get; set; }

        public virtual Descriptiontype DescriptionType { get; set; }
        public virtual ICollection<Posdetail> Posdetail { get; set; }
    }
}

和

    using System;
using System.Collections.Generic;

namespace ThePositionerRazor2.Models
{
    public partial class Posdetail
    {
        public int PosdetailId { get; set; }
        public int PositionId { get; set; }
        public int Workitem { get; set; }
        public int? TimeSpent { get; set; }
        public int? ImportanceId { get; set; }
        public double? TimeNrmz { get; set; }
        public int? Knowdepth { get; set; }
        public int? Need { get; set; }
        public int? TimeCalc { get; set; }
        public double? Postskval { get; set; }
        public double? Ftetime { get; set; }
        public double? Ftesal { get; set; }
        public DateTime Lastupdated { get; set; }

        public virtual Imp Importance { get; set; }
        public virtual Knowdep KnowdepthNavigation { get; set; }
        public virtual Possummary Position { get; set; }
        public virtual Timescale TimeSpentNavigation { get; set; }
        public virtual Workhier WorkitemNavigation { get; set; }
    }
}

Answer 1

确认您的要求：

在您的主索引页面中，您有一个列表 Possummary。当您单击 Details link 时，它将显示属于列表 Posdetail 的详细信息Possummary你在Detailspage.Then中选择你点击Createlink，它会显示Possummary 你在Create页面开头选择的PositionId。

满足您的要求：

您可以在 Create 中传递 PositionId link.Then 通过此 PositionId:

设置选择列表的默认选择值

public IActionResult OnGet(int PositionID)
{
    ViewData["ImportanceId"] = new SelectList(_context.Imp, "ImportanceId", "ImportanceId");
    ViewData["Knowdepth"] = new SelectList(_context.Knowdep, "DepthId", "DepthId");

    //change here....
    ViewData["PositionId"] = new SelectList(_context.Possummary, "PositionId", "PositionNbr", PositionID);
    ViewData["TimeSpent"] = new SelectList(_context.Timescale, "TimevalId", "TimevalId");
    ViewData["Workitem"] = new SelectList(_context.Workhier, "Workitemid", "Workitemid");
    return Page();
}

整个工作演示：

型号：

public class Possummary
{
    public Possummary()
    {
        Posdetail = new HashSet<Posdetail>();
    }
    [Key]
    public int PositionId { get; set; }
    public string PositionNbr { get; set; }
    public string WorkTitle { get; set; }
    public string Purpose { get; set; }
    public double? JobValue { get; set; }
    public double? TimeTotal { get; set; }
    public double? Fte { get; set; }
    public double? Salary { get; set; }
    public DateTime? Lastupdated { get; set; }
    public string JobFamily { get; set; }
    public int? DescriptionTypeId { get; set; }

    public virtual Descriptiontype DescriptionType { get; set; }
    public virtual ICollection<Posdetail> Posdetail { get; set; }
}
public class Descriptiontype
{
    public int Id { get; set; }
    public string Name { get; set; }
}

public partial class Posdetail
{
    public int PosdetailId { get; set; }
    public int PositionId { get; set; }
    public int Workitem { get; set; }
    public int? TimeSpent { get; set; }
    public int? ImportanceId { get; set; }
    public double? TimeNrmz { get; set; }
    public int? Knowdepth { get; set; }
    public int? Need { get; set; }
    public int? TimeCalc { get; set; }
    public double? Postskval { get; set; }
    public double? Ftetime { get; set; }
    public double? Ftesal { get; set; }
    public DateTime Lastupdated { get; set; }

    public virtual Imp Importance { get; set; }
    public virtual Knowdep KnowdepthNavigation { get; set; }
    public virtual Possummary Position { get; set; }
    public virtual Timescale TimeSpentNavigation { get; set; }
    public virtual Workhier WorkitemNavigation { get; set; }
}
public class Imp
{
    [Key]
    public int ImportanceId { get; set; }
    public string Name { get; set; }
}
public class Knowdep
{
    [Key]
    public int DepthId { get; set; }
    public string Name { get; set; }
}
public class Timescale
{
    [Key]
    public int TimevalId { get; set; }
    public string Name { get; set; }
}
public class Workhier
{
    [Key]
    public int Workitemid { get; set; }
    public string Name { get; set; }
}

Possummarys/Index.cshtml:

@page
@model IndexModel
<h1>Index</h1>

<p>
    <a asp-page="Create">Create New</a>
</p>
<table class="table">
    <thead>
        <tr>
            <th>
                @Html.DisplayNameFor(model => model.Possummary[0].PositionNbr)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Possummary[0].WorkTitle)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Possummary[0].Purpose)
            </th>
     
            <th></th>
        </tr>
    </thead>
    <tbody>
@foreach (var item in Model.Possummary) {
        <tr>
            <td>
                @Html.DisplayFor(modelItem => item.PositionNbr)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.WorkTitle)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.Purpose)
            </td>          
            <td>
                <a asp-page="./Edit" asp-route-id="@item.PositionId">Edit</a> |
                <a asp-page="./Details" asp-route-id="@item.PositionId">Details</a> |
                <a asp-page="./Delete" asp-route-id="@item.PositionId">Delete</a>
            </td>
        </tr>
}
    </tbody>

Possummarys/Index.cshtml.cs:

namespace RazorProj3_1.Pages.Possummarys
{
    public class IndexModel : PageModel
    {
        private readonly RazorProj3_1Context _context;

        public IndexModel(RazorProj3_1Context context)
        {
            _context = context;
        }

        public IList<Possummary> Possummary { get;set; }

        public async Task OnGetAsync()
        {
            Possummary = await _context.Possummary.ToListAsync();
        }
    }
}

Possummarys/Details.cshtml:

@page
@model DetailsModel
     

    //focus here...
    <a asp-page="/PositionDetail/Create" asp-route-PositionID="@Model.Posdetail[0].PositionId" >Create New</a>
<h1>Postition Detail</h1>
<table class="table">
    <thead>
        <tr>
            <th>
                @Html.DisplayNameFor(model => model.Posdetail[0].Position)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Posdetail[0].WorkitemNavigation)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Posdetail[0].TimeNrmz)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Posdetail[0].Importance)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Posdetail[0].Lastupdated)
            </th>
            <th></th>
        </tr>
    </thead>
    <tbody>
        @foreach (var item in Model.Posdetail)
        {
        <tr>
            <td>
                @Html.DisplayFor(modelItem => item.Position.PositionNbr)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.WorkitemNavigation.Workitemid)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.TimeNrmz)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.ImportanceId)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.Lastupdated)
            </td>
            <td>
                <a asp-page="./Edit" asp-route-id="@item.PosdetailId">Edit</a> |
                <a asp-page="./Details" asp-route-id="@item.PosdetailId">Details</a> |
                <a asp-page="./Delete" asp-route-id="@item.PosdetailId">Delete</a>
            </td>
        </tr>
        }
    </tbody>
</table>

Possummarys/Details.cshtml.cs:

public class DetailsModel : PageModel
{
    private readonly RazorProj3_1Context _context;

    public DetailsModel(.RazorProj3_1Context context)
    {
        _context = context;
    }

    public IList<Posdetail> Posdetail { get; set; }

    public async Task<IActionResult> OnGetAsync(int? id)
    {

        Posdetail = await _context.Posdetail.Include(p=>p.Position)
                            .Include(p=>p.WorkitemNavigation)
                            .Where(a=>a.PositionId==id).ToListAsync();

        return Page();
    }
}

PositionDetail/Create.cshtml:（和你提供的一样）

@page
@model CreateModel

@{
    ViewData["Title"] = "Create";
}
<h1>Create</h1>

<h4>Posdetail</h4>
<hr />
<div class="row">
    <div class="col-md-4">
        <form method="post">
            <div asp-validation-summary="ModelOnly" class="text-danger"></div>
            <div class="form-group">
                <label asp-for="Posdetail.PositionId" class="control-label"></label>
                <select asp-for="Posdetail.PositionId" class="form-control" asp-items="ViewBag.PositionId"></select>
            </div>
            <div class="form-group">
                <label asp-for="Posdetail.Workitem" class="control-label"></label>
                <select asp-for="Posdetail.Workitem" class="form-control" asp-items="ViewBag.Workitem"></select>
            </div>
            <div class="form-group">
                <label asp-for="Posdetail.TimeSpent" class="control-label"></label>
                <select asp-for="Posdetail.TimeSpent" class="form-control" asp-items="ViewBag.TimeSpent"></select>
            </div>
            <div class="form-group">
                <label asp-for="Posdetail.ImportanceId" class="control-label"></label>
                <select asp-for="Posdetail.ImportanceId" class="form-control" asp-items="ViewBag.ImportanceId"></select>
            </div>
            <div class="form-group">
                <label asp-for="Posdetail.TimeNrmz" class="control-label"></label>
                <input asp-for="Posdetail.TimeNrmz" class="form-control" />
                <span asp-validation-for="Posdetail.TimeNrmz" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Posdetail.Knowdepth" class="control-label"></label>
                <select asp-for="Posdetail.Knowdepth" class="form-control" asp-items="ViewBag.Knowdepth"></select>
            </div>
            <div class="form-group">
                <label asp-for="Posdetail.Need" class="control-label"></label>
                <input asp-for="Posdetail.Need" class="form-control" />
                <span asp-validation-for="Posdetail.Need" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Posdetail.TimeCalc" class="control-label"></label>
                <input asp-for="Posdetail.TimeCalc" class="form-control" />
                <span asp-validation-for="Posdetail.TimeCalc" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Posdetail.Postskval" class="control-label"></label>
                <input asp-for="Posdetail.Postskval" class="form-control" />
                <span asp-validation-for="Posdetail.Postskval" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Posdetail.Ftetime" class="control-label"></label>
                <input asp-for="Posdetail.Ftetime" class="form-control" />
                <span asp-validation-for="Posdetail.Ftetime" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Posdetail.Ftesal" class="control-label"></label>
                <input asp-for="Posdetail.Ftesal" class="form-control" />
                <span asp-validation-for="Posdetail.Ftesal" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Posdetail.Lastupdated" class="control-label"></label>
                <input asp-for="Posdetail.Lastupdated" class="form-control" />
                <span asp-validation-for="Posdetail.Lastupdated" class="text-danger"></span>
            </div>
            <div class="form-group">
                <input type="submit" value="Create" class="btn btn-primary" />
            </div>
        </form>
    </div>
</div>

<div>
    <a asp-page="Index">Back to List</a>
</div>

@section Scripts {
    @{await Html.RenderPartialAsync("_ValidationScriptsPartial");}
}

PositionDetail/Create.cshtml.cs:

public class CreateModel : PageModel
{
    private readonly RazorProj3_1Context _context;

    public CreateModel(RazorProj3_1Context context)
    {
        _context = context;
    }

    public IActionResult OnGet(int PositionID)
    {
        ViewData["ImportanceId"] = new SelectList(_context.Imp, "ImportanceId", "ImportanceId");
        ViewData["Knowdepth"] = new SelectList(_context.Knowdep, "DepthId", "DepthId");

        //change here....
        ViewData["PositionId"] = new SelectList(_context.Possummary, "PositionId", "PositionNbr", PositionID);
        ViewData["TimeSpent"] = new SelectList(_context.Timescale, "TimevalId", "TimevalId");
        ViewData["Workitem"] = new SelectList(_context.Workhier, "Workitemid", "Workitemid");
        return Page();
    }

    [BindProperty]
    public Posdetail Posdetail { get; set; }
   
    public async Task<IActionResult> OnPostAsync()
    {
        //the same as yours...
    }
}

结果：

在 dot net core razor 页面中 - 你如何默认创建页面上的下拉选项？

in dot net core razor pages - how do you default a dropdown choice on a create page?

parent-child

asp.net-core

razor-pages