ASP.NET MVC upload image

问题

I've found some code to do this and tried to implement it into my project, but so far it has been unsuccessful. I don't get any errors, but I don't see any images being stored in my images directory inside visual studio.

View:

  @using (Html.BeginForm())
{
    <span>Please enter your story here:</span>
    <textarea id="testimonial" name="testimonial"></textarea>
    <button type="submit">Submit</button>
    <input type="file" name="file" />
}

Controller:

[HttpPost]
    public ActionResult Create(Testimonials testimonials)
    {
        if (Request.Files.Count > 0)
        {
            var file = Request.Files[0];

            if (file != null && file.ContentLength > 0)
            {
                var fileName = Path.GetFileName(file.FileName);
                var path = Path.Combine(Server.MapPath("~/Images/"), fileName);
                file.SaveAs(path);
            }
        }


        TestimonialsContext testContext = new TestimonialsContext();
        testContext.testimonialContext.Add(testimonials);
        testContext.SaveChanges();
        return RedirectToAction("Index");
    }

The part below the if block works fine. That just saves the content of a textarea to the database. Any thoughts? Do I need to make any changes to my model?

model:

[Table("Testimonials")]
public class Testimonials
{
    public int Id { get; set; }
    public string Testimonial { get; set; }
}

context class:

public class TestimonialsContext:DbContext
{
    public DbSet<Testimonials> testimonialContext { get; set; }
}

回答1:

Your file is not being posted because you do not have the necessary enctype attribute on the form. Change the view to use

@using (Html.BeginForm("Create", "Testimonials", FormMethod.Post, new { enctype = "multipart/form-data" }))

You will now get the file and save it, but there is no relationship to your Testimonials object so you cannot retrieve it. You will need to add additional fields in your Testimonials table to store the file properties (or a separate table if a Testimonials can have multiple images). I also recommend you save the file to your server with a unique identifier (e.g. a Guid to prevent accidental overwriting if 2 users upload files with the same name). You revised model might be

public class Testimonials
{
    public int Id { get; set; }
    public string Testimonial { get; set; }
    public string ImagePath { get; set; }
    public string ImageDisplayName { get; set; }
}

I would also recommend using a view model for the view that includes the above properties plus public HttpPostedFileBase Image { get; set; } so that you can strongly bind to the model and add validation attributes (for example a [FileSize] attribute assuming you do not want to allow users to upload 2GB files). Your controller method would then be

[HttpPost]
public ActionResult Create(TestimonialVM model)
{
    // ModelState.IsValid check omitted
    Testimonials testimonials = new Testimonials();
    // map view model properties to the data model
    ....
    if (model.Image != null && model.Image.ContentLength > 0)
    {
        string displayName = model.Image.FileName;
        string fileExtension = Path.GetExtension(displayName);
        string fileName = string.Format("{0}.{1}", Guid.NewGuid(), fileExtension)
        string path = Path.Combine(Server.MapPath("~/Images/"), fileName)
        model.Image.SaveAs(path);
        // Update data model
        testimonials.ImagePath = path;
        testimonials.ImageDisplayName = displayName;
    }
    TestimonialsContext testContext = new TestimonialsContext();
    testContext.testimonialContext.Add(testimonials);
    testContext.SaveChanges();
    return RedirectToAction("Index");
}

来源：https://stackoverflow.com/questions/35904830/asp-net-mvc-upload-image

标签

asp.net-mvc

upload