Question

我正在尝试制作可以管理客户的应用。我所有的客户都有自己管理的客户。因此，我用两个表tboClienti分别为客户和tboSottoClienti分别作为我的“下客户”数据库。

这是表的结构：

Structure of table Clients - tboClienti和structure of table Under Clients - tboSottoClienti。

我正在为“下属客户”进行CRUD操作，我想创建一个下拉列表，从中可以选择我的客户并为下属客户插入信息（姓名，姓氏，公司，电话）。

>

我制作了一个控制器模型并为我的under客户查看，但是我不知道如何在“查看剃刀页面”中列出列表。

这是控制器：

public class SottoClientiController : Controller
{
    private readonly AppDbContext _db;

    public SottoClientiController(AppDbContext db)
    {
        _db = db;
    }

    public IActionResult Index()
    {
        var datiSottoClienti = _db.tboSottoClienti.ToList();
        return View(datiSottoClienti);
    }


    public IActionResult CreareLista()
    {
        ViewData["lstClieti"] = new SelectList(_db.tboClienti, "Id", "Nome_azienda");
        return View();
    }
    public IActionResult CreareSottoCliente()
    {
        return View();
    }

    [HttpPost]
    public async Task<IActionResult> CreareSottoCliente(SottoCliente sottoCliente) 
    {
        if (ModelState.IsValid)
        {
            _db.Add(sottoCliente);
            await _db.SaveChangesAsync();
            return RedirectToAction("Index");
        }

        return View(sottoCliente);
    }
}

这是模型类：

public class SottoCliente
{
    [Key]
    public int Id { get; set; }

    [Required(ErrorMessage = "Inserisci il nome di proprietario dell'azienda")]
    [Display(Name = "Nome")]
    public string Nome { get; set; }

    [Required(ErrorMessage = "Inserisci il cognome di proprietario dell'azienda")]
    [Display(Name = "Cognome")]
    public string Cognome { get; set; }

    [Display(Name = "Azienda")]
    public string Azienda { get; set; }

    [Required(ErrorMessage = "Inserisci il numero di telefono dell'azienda")]
    [DataType(DataType.PhoneNumber)]
    [Display(Name = "Telefono")]
    [RegularExpression(@"^\(?([0-9]{3})\)?[-. ]?([0-9]{3})[-. ]?([0-9]{4})$",
       ErrorMessage = "Numero non valido")]
    public string Cellulare { get; set; }
}

我不知道如何从表tboClienti中获取数据以将其插入到列表中。这样，我就可以为我的下层客户端选择客户端。

这是视图：

<h4>Under Client</h4>
<hr />
<div class="row">
    <div class="col-md-4">
        <form asp-action="CreareSottoCliente">
            <div asp-validation-summary="ModelOnly" class="text-danger"></div>

           <div class="form-group">
            <label asp-for="Azienda" class="control-label"></label>
            <select asp-for="Azienda" class="form-control" asp-items="@ViewBag.lstClieti"></select>
            <span asp-validation-for="Azienda" class="text-danger"></span>
        </div>

            <div class="form-group">
                <label asp-for="Id" class="control-label"></label>
                <input asp-for="Id" class="form-control" />
                <span asp-validation-for="Id" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Nome" class="control-label"></label>
                <input asp-for="Nome" class="form-control" />
                <span asp-validation-for="Nome" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Cognome" class="control-label"></label>
                <input asp-for="Cognome" class="form-control" />
                <span asp-validation-for="Cognome" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Azienda" class="control-label"></label>
                <input asp-for="Azienda" class="form-control" />
                <span asp-validation-for="Azienda" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Cellulare" class="control-label"></label>
                <input asp-for="Cellulare" class="form-control" />
                <span asp-validation-for="Cellulare" class="text-danger"></span>
            </div>
            <div class="form-group">
                <input type="submit" value="Create" class="btn btn-primary" />
            </div>
        </form>
    </div>
</div>

我将连接字符串插入appsettings.json，然后将其添加到ConfigureServices();。

这是数据库上下文的类：

 public class AppDbContext: DbContext
 {
        public AppDbContext(DbContextOptions<AppDbContext> options): base (options)
        {
        }

        public DbSet<Tecnico> tboTecnici { get; set; }
        public DbSet<Cliente> tboClienti { get; set; }
        public DbSet<SottoCliente> tboSottoClienti { get; set; }
}

有人建议如何从数据库中获取数据并将其插入列表吗？

谢谢！

Answer 1

在ASP.NET Core MVC中，您的下拉列表HTML代码如下所示：

 <div class="form-group">
        <label asp-for="NewsTypeId" class="control-label"></label>
        <select asp-for="NewsTypeId" class="form-control" asp-items="@ViewBag.NewsTypeId"></select>
        <span asp-validation-for="NewsTypeId" class="text-danger"></span>
    </div>

和在C＃控制器中

public IActionResult Create()
{
    ViewData["NewsTypeId"] = new SelectList(_context.TypeOfNews, "TypeId", "TypeName");
    return View();
}

原始答案：https://stackoverflow.com/a/55843644/3559462

有关逐步操作的详细信息，请查看以下链接：https://www.c-sharpcorner.com/article/binding-dropdown-list-with-database-in-asp-net-core-mvc/

Answer 2

调试代码，并确保您的ViewData["lstClieti"]确实存在值。

请确保您的视图名称是否为CreareLista。如果视图名称为CreareSottoCliente。更改如下：

//public IActionResult CreareLista()
//{
//    ViewData["lstClieti"] = new SelectList(_db.tboClienti, "Id", "Nome_azienda");
//    return View();
//}
public IActionResult CreareSottoCliente()
{
    ViewData["lstClieti"] = new SelectList(_db.tboClienti, "Id", "Nome_azienda");
    return View();
}

整个演示

1。型号：

public class SottoCliente
{
    [Key]
    public int Id { get; set; }

    [Required(ErrorMessage = "Inserisci il nome di proprietario dell'azienda")]
    [Display(Name = "Nome")]
    public string Nome { get; set; }

    [Required(ErrorMessage = "Inserisci il cognome di proprietario dell'azienda")]
    [Display(Name = "Cognome")]
    public string Cognome { get; set; }

    [Display(Name = "Azienda")]
    public string Azienda { get; set; }

    [Required(ErrorMessage = "Inserisci il numero di telefono dell'azienda")]
    [DataType(DataType.PhoneNumber)]
    [Display(Name = "Telefono")]
    [RegularExpression(@"^\(?([0-9]{3})\)?[-. ]?([0-9]{3})[-. ]?([0-9]{4})$",
       ErrorMessage = "Numero non valido")]
    public string Cellulare { get; set; }
}
public class Cliente
{
    public int Id { get; set; }
    public string Nome_azienda { get; set; }
}

2。视图名称应为CreareSottoCliente.cshtml。

3.Controller：

public class SottoClientiController : Controller
{
    private readonly MvcProj3_1Context _db;
    public SottoClientiController(MvcProj3_1Context db)
    {
        _db = db;
    }

    public IActionResult Index()
    {
        var datiSottoClienti = _db.tboSottoClienti.ToList();
        return View(datiSottoClienti);
    }
    //SottoClienti/CreareSottoCliente
    public IActionResult CreareSottoCliente()
    {
        ViewData["lstClieti"] = new SelectList(_db.tboClienti, "Id", "Nome_azienda");
        return View();
    }

    [HttpPost]
    public async Task<IActionResult> CreareSottoCliente(SottoCliente sottoCliente)
    {
        if (ModelState.IsValid)
        {
            _db.Add(sottoCliente);
            await _db.SaveChangesAsync();
            return RedirectToAction("Index");
        }

        return View(sottoCliente);
    }
}

4.DbContext：

public class MvcProj3_1Context : DbContext
{
    public MvcProj3_1Context (DbContextOptions<MvcProj3_1Context> options)
        : base(options)
    {
    }       
    public DbSet<Tecnico> tboTecnici { get; set; }
    public DbSet<Cliente> tboClienti { get; set; }
    public DbSet<SottoCliente> tboSottoClienti { get; set; }
}

5.Startup.cs：

public void ConfigureServices(IServiceCollection services)
{
    services.AddControllersWithViews();

    services.AddDbContext<MvcProj3_1Context>(options =>
            options.UseSqlServer(Configuration.GetConnectionString("MvcProj3_1Context")));
}

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
    app.UseHttpsRedirection();
    app.UseStaticFiles();

    app.UseRouting();

    app.UseAuthorization();

    app.UseEndpoints(endpoints =>
    {
        endpoints.MapControllerRoute(
            name: "default",
            pattern: "{controller=Home}/{action=Index}/{id?}");
    });
}

6.appSettings.json：

"ConnectionStrings": {
   "MvcProj3_1Context": "Server=(localdb)\\mssqllocaldb;Database=DatabaseName;Trusted_Connection=True;MultipleActiveResultSets=true"
}

结果：

如何从数据库中填充ASP.NET实体框架中的列表

2 个答案: