How to display binary images from Database to edit

问题:

I am storing images in Database as Binary Images successfully. I want to display these images in Edit form to modify and save changes. System.OutOfMemoryException' was thrown in Edit.cshtml form while displaying Binary Images from Database.

Can someone please correct my code.

Model class:

public class Accommodation
    {
        [Key]
        public string A_Unique_Id { get; set; }

        public byte[] Picture1 { get; set; }

        public byte[] Picture2 { get; set; }

        public byte[] Picture3 { get; set; }


  }

// GET: /Accommodation/Edit/5

public ActionResult Edit(string id)
    {
        Accommodation accommodation = db.Accommodation.Find(id);
        ViewBag.SelectedAustraliaStateId = new SelectList(db.AustraliaStates, "AustraliaStateId", "AustraliaStateName", accommodation.SelectedAustraliaStateId);

        return View(accommodation);
    }

// POST: /Accommodation/Edit/5

[HttpPost]
public ActionResult Edit(Accommodation accommodation)
{
    if (ModelState.IsValid)
    {
        db.Entry(accommodation).State = EntityState.Modified;

        //the following line is for re-assigning back the DDL modified value.
        accommodation.State = accommodation.SelectedAustraliaStateId;

        db.SaveChanges();
        return RedirectToAction("Index");
    }
    return View(accommodation);
}

Edit.cshtml

<div class="editor-label">
        @Html.LabelFor(model => model.Picture1)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.Picture1)
        @Html.ValidationMessageFor(model => model.Picture1)
    </div>

ERROR MESSAGE: Exception of type 'System.OutOfMemoryException' was thrown at line @Html.EditorFor(model => model.Picture1)

回答1:

To display image in your view

View

<form  method="post" enctype="multipart/form-data">
@{
    if (Model.Picture1 != null)
      {
         string imageBase64 = Convert.ToBase64String(Model.Picture1);
         string imageSrc = string.Format("data:image/gif;base64,{0}", imageBase64);
         <img src="@imageSrc" width="100" height="100" />
      }
  }
    <input type="file" name="photo" id="files" accept="image/*;capture=camera">
    <button type="button">Submit</button>
  </form>

Controller

[HttpPost]
public ActionResult Edit(Accommodation accommodation)
{

  if (Request.Files["files"] != null)
    {
            byte[] Image;
            using (var binaryReader = new BinaryReader(Request.Files["files"].InputStream))
            {
                Image = binaryReader.ReadBytes(Request.Files["files"].ContentLength);
            }
    }
    accommodation.Picture1=Image;
  //your code to save data
}

回答2:

byte[] imageByteData = System.IO.File.ReadAllBytes(imageFile);

string imageBase64Data = Convert.ToBase64String(imageByteData);

string imageDataURL = string.Format("data:image/jpg;base64{0}",imageBase64Data);

Session["photo"] = imageDataURL;

In _layout.cshtml page add this line.