HttpPostedFileBase 在 MVC Razor 页面中始终为 null

Question

I have created one form where user can upload profile photo, and it stores in database as byte array. but in post method i'm getting the value of HttpPostedFileBase property is null.

<form id="profile-form" method="post" enctype="multipart/form-data">
    <div class="col-md-6">
       <div class="row">
            <div class="form-group col-md-6">
                 <img id="output" style="height:200px; width:200px;" />
            </div>
       </div>
       <div class="row">
            <div class="form-group col-md-12">
                <input asp-for="Input.ProfilePhoto" type="file" onchange="loadFile(event)" class="form-control">
            </div>
       </div>
       <button type="submit" class="btn btn-default" value="Upload">Save</button>
   </div>
</form>

public class Input
{
      [Display(Name = "Profile Photo")]
      public HttpPostedFileBase ProfilePhoto { get; set; }
}

public async Task<IActionResult> OnPostAsync()
{

}

Answer 1

The ASP.NET Core equivalent to HttpPosteFileBase is IFormFile :

[BindProperty]
public IFormFile Upload { get; set; }

public async Task OnPostAsync()
{
    var file = Path.Combine(_environment.ContentRootPath, "uploads", Upload.FileName);
    using (var fileStream = new FileStream(file, FileMode.Create))
    {
        await Upload.CopyToAsync(fileStream);
    }
}

You also need to decorate the IFormFile property (or the class that it is in) with the [BindProperty] attribute.

Ref: Uploading Files in Razor Pages