使用Entity FrameWork从sql db查看和下载文件

Question

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

Answer 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.

Answer 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" />
       }
  }