CODEWITHSUNDEEP
c#linq
johns
johns

Reputation: 183

image from database display in PicutreBox, using LINQ query

I have a database with a table named Products which contains pictures of the products.

To store an image in memory one does

public byte[] Picture

So in my database it's a varbinary type (automaticly converted) So, what i want to do is to display in pictureBox1.Image my image from database. Something like this:

 var q_pic = from p in context.Products
                         where p.ID == value // Id of product that i want 
                         select new
                         {
                             p.Picture
                         };

and now

picutreBox1.Image = ??

cause

pictureBox1.Image = q_pic // doeasn't work

I have tried this:

var bytes = from p in context.Products
                        where p.ID == value // Id of product that i want 
                        select p.Picture;
            if (bytes != null)
            {
                using (var ms = new MemoryStream(bytes))
                {
                    using (var image = Image.FromStream(ms))
                    {
                        pictureBox1.Image = (Image)image.Clone();
                    }
                }
            }

and getting this

Error   1   The best overloaded method match for 'System.IO.MemoryStream.MemoryStream(byte[])' has some invalid arguments   

Error   2   Argument 1: cannot convert from 'System.Linq.IQueryable<byte[]>' to 'byte[]'

Upvotes: 2

Views: 3763

Answers (5)

Abundio C. Navarro
Abundio C. Navarro

Reputation: 1

DataBonzClinicDataContext db = new DataBonzClinicDataContext();

            var tsel = (from u in db.tblsysusers 
                       where (u.pass_id==cbxUser.Text.ToString().Trim()) 
                      select u.pass_imgid).First();            

            if (tsel != null)
            {
               var imgdata = tsel.ToArray();
                System.IO.MemoryStream ms = new System.IO.MemoryStream(imgdata);
                pictureBox1.Image = Image.FromStream(ms);
            }

Upvotes: 0

mr.bl4ck
mr.bl4ck

Reputation: 1

just make

byte[] imgdata;


string id = dataGridViewX1.SelectedRows[0].Cells[0].Value.ToString();
var q = db.tbl_aezas.First(c => c.id == id);
imgdata = q.image.ToArray();
System.IO.MemoryStream ms = new System.IO.MemoryStream(imgdata);
pictureBox1.Image = Image.FromStream(ms);

Upvotes: 0

IDeveloper
IDeveloper

Reputation: 1299

When you use LINQ, you get 'System.Data.Linq.Binary' type from database. This type has a ToArray() method, which returns byte[]. To you should correct you code like this:

var bytes = from p in context.Products
                        where p.ID == value // Id of product that i want 
                        select p.Picture;
byte[] trueBytes = bytes.ToArray();
if (trueBytes != null)
{
    using (var ms = new MemoryStream(trueBytes))
    {
        using (var image = Image.FromStream(ms))
        {
            pictureBox1.Image = (Image)image.Clone();
        }
    }
}

Upvotes: 0

Reed Copsey
Reed Copsey

Reputation: 564791

You probably want something more like:

var q_pic = from p in context.Products
                     where p.ID == value // Id of product that i want 
                     select p.Picture;

// FirstOrDefault will return null if there were no matches
pictureBox1.Image = q_pic.FirstOrDefault();

The main issues in your original were you were using an anonymous type (unnecessarily), and trying to assign to an IEnumerable<T>, not just the picture itself. Removing the new {... from the query solves the first issue, and using FirstOrDefault extracts a single T (the first) from the IEnumerable<T>.

Given your comment, it's obvious that your query is return a byte[], not an image. You would need to write it as:

var first = context.Products.FirstOrDefault(p => p.ID == value);
if (first != null)
{
     using (var ms = new MemoryStream(first.Picture)) 
     {
         using(var image = Image.FromStream(ms)) 
         {
             pictureBox1.Image = (Image)image.Clone();
         }
     }
}

Upvotes: 1

rclement
rclement

Reputation: 1714

What Reed Copsey lists will get you to the point where you have retrieved the byte[] on the Product object. To put it in the Image property on the PictureBox you will need to convert the byte array to an Image.

 using (var ms = new System.IO.MemoryStream(q_pic)) {
    using(var img = Image.FromStream(ms)) {
       pictureBox1.Image = img;
    }
 }

Upvotes: 1

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