状态.IsValid= False上传图像(bootstrap/ core MVC)

Question

我正在尝试上传图像，这是视图:

@model CrearAmigoModelo
@{
ViewBag.Title = "Nuevo amigo";
}
<form asp-controller="Home" asp-action="Create" method="post">
<div asp-validation-summary="All" class="text-danger"> </div>
<div class="form-group row">
<label asp-for="Nombre" class="col-sm-2 col-form-label"></label>
<div class="col-sm-10">
<input asp-for="Nombre" class="form-control" placeholder="Nombre" />
<span asp-validation-for="Nombre" class="text-danger"></span>
</div>
</div>
<div class="form-group row">
<label asp-for="Email" class="col-sm-2 col-form-label"></label>
<div class="col-sm-10">
<input asp-for="Email" class="form-control" placeholder="E-mail" />
<span asp-validation-for="Email" class="text-danger"></span>
</div>
</div>
<div class="form-group row">
<label asp-for="Ciudad" class="col-sm-2 col-form-label"></label>
<div class="col-sm-10">
<select asp-for="Ciudad" class="custom-select mr-sm-2" asp-items="Html.GetEnumSelectList<Provincia>()">
:
<option value="">Seleccione uno</option>
</select>
<span asp-validation-for="Ciudad" class="text-danger"></span>
</div>
</div>
<div class="form-group row">
<label asp-for="Foto" class="col-sm-2 col-form-label">-------------------------</label>
<div class="col-m-10">
<div class="custom-file">
<input type="file" asp-for="Foto" class="form-control custom-file-input"/>
<label class="custom-file-label"> Selecciona un fichero </label>
</div>
</div>
</div>

<div class="form-group row">
<div class="col-sm-10">
<button type="submit" class="btn btn-primary">Nuevo</button>
</div>
</div>

@section Scripts{
<script>
$(document).ready(function() {
$('.custom-file-input').on("change", function (){
var fileName=$(this).val().split("\").pop();
$(this).next('.custom-file-label').html(fileName);
});
});
</script>
}
</form>

这是控制器中的方法:

[HttpPost]
public IActionResult Create(CrearAmigoModelo a)
{
if (ModelState.IsValid)
{
string guidImagen = null;
if (a.Foto != null)
{
string ficherosImagenes = Path.Combine(_env.WebRootPath, "images");
guidImagen = Guid.NewGuid().ToString() + a.Foto.FileName;
string rutaDefinitiva = Path.Combine(ficherosImagenes, guidImagen);
a.Foto.CopyTo(new FileStream(rutaDefinitiva, FileMode.Create));
}

Amigo nuevoAmigo = new Amigo();
nuevoAmigo.Nombre = a.Nombre;
nuevoAmigo.Email = a.Email;
nuevoAmigo.Ciudad = a.Ciudad;
nuevoAmigo.rutaFoto = guidImagen;
//nuevoAmigo.rutaFoto = "++";
amigoAlmacen.nuevo(nuevoAmigo);
return RedirectToAction("details", new { id = nuevoAmigo.Id });
}
return View();
}

控制器在字段"Foto"中获得null，所有其他字段都正确传递。在视图中，当我完成所有字段并按下按钮发送表单时，总是显示消息&;Foto字段是必需的&;即使我已经选择了文件

Answer 1

要包含文件的表单需要有一个编码类型为multipart/form-data。

<form enctype="multipart/form-data">
</form>

请参考以下Microsoft文档获取更多信息:

在ASP中上传文件网络核心