view and download File from sql db using Entity FrameWork

问题

Am new for hamdling Entity Framework.I use the following code for insert the file from fileupload button in mvc4

public ActionResult Index(NewUserModel newUser)
        {
            Resume newuserResume = new Resume();
            if (Request != null)
            {
                HttpPostedFileBase file = Request.Files["UploadedFile"];
                if ((file != null) && (file.ContentLength > 0) && !string.IsNullOrEmpty(file.FileName))
                {
                    string fileName = file.FileName;
                    string fileextn = Path.GetExtension(fileName);
                    if (fileextn == ".pdf" || fileextn == ".doc")
                    {
                        string fileContentType = file.ContentType;
                        byte[] fileBytes = new byte[file.ContentLength];
                        file.InputStream.Read(fileBytes, 0, Convert.ToInt32(file.ContentLength));
                        newuserResume.Resumes = fileBytes;
                        Hrentitymodel.Resumes.Add(newuserResume);
                        Hrentitymodel.SaveChanges();
                    }
                    else {
                        ViewBag.FileExtn = "File Should be in .doc or .pdf Format";
                    }
                }
            }
            return View("Index");
        }

It will working fine which means the file stored in DB with Varbinary(max) Format. Now,How to view and download the file from sql db using entity framework in MVC4

回答1:

Assuming a basic Model of:

public class Resume
{
public int ResumeID {get;set;}
public string Name { get; set; }
public byte[] Resume { get;set; }
}

Store the file using:

resume.Resume = new byte[file.ContentLength];
file.InputStream.Read(resume.Resume, 0, (file.ContentLength));

(which you are!)

To view the file you will want to return a FileContentResult.

In your view you can do something like:

@Html.ActionLink("View Resume", "ViewResume", "ResumeController", new { id = resume.ResumeID }, new { @target= "_blank" })

And the controller action will call the Action to return the file:

    public FileContentResult ViewResume(int id)
    {
        if (id == 0) { return null; }
        Resume resume = new Resume();
        ResumeContext rc = new ResumeContext();
        resume = rc.Resume.Where(a => a.ResumeID == id).SingleOrDefault();
        Response.AppendHeader("content-disposition", "inline; filename=file.pdf"); //this will open in a new tab.. remove if you want to open in the same tab.
        return File(resume.Resume, "application/pdf");
    }

This is the basic method I have implemented when storing files in the DB.

回答2:

To view the file

view

 @{
     if (Model.Logo != null)
       {
         string imageBase64 = Convert.ToBase64String(Model.Logo);
         string imageSrc = string.Format("data:image/gif;base64,{0}", imageBase64);
         <img src="@imageSrc" width="100" height="100" />
       }
  }

来源：https://stackoverflow.com/questions/23822058/view-and-download-file-from-sql-db-using-entity-framework