can a sole generic handler be used to retrieve multiple images from sql db?

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I am using generic handler to retrieve a single image from sql db. Can this handler retrieve multiple images from a table???
here is my table structure:

create table book1
(
Row_id int not null IDENTITY,
name varchar(20) not null primary key,
author varchar(10),
category varchar(30),
price varchar(10),
details varchar(1000),
qty varchar (20),
imagename varchar(100),
image1 image
)

here's the code i am using in the handler:

public class imHandler : IHttpHandler 
{
    public void ProcessRequest (HttpContext context)
    {
        string strConn = " ....";
        SqlConnection con = new SqlConnection(strConn);
        con.Open();
        try
        {
            string st = "select top 1 image1 from book1 order by Row_id desc";
            SqlCommand cmd = new SqlCommand(st, con);
            SqlDataReader sdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
            if (sdr.Read())
                
            {
                byte[] imgByte = (byte[])sdr["image1"];
                MemoryStream memoryStream = new MemoryStream();
                memoryStream.Write(imgByte, 0, imgByte.Length);
                System.Drawing.Image imagen = System.Drawing.Image.FromStream(memoryStream);
                context.Response.BinaryWrite(imgByte);
                
                
            }
        }
        catch (Exception ex)
        {
            throw ex;
        }
        finally
        {
            con.Close();
        }

and finally:

btn1_click()
{
image1.imageurl="~/imhandler.ashx"
}

Can handler return multiple images???

Posted 23-May-13 8:03am

Swayam231

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Comments

Swayam231 23-May-13 14:05pm

The last code is written in another page default.aspx having few imagecontrols and buttons.

ZurdoDev 23-May-13 14:23pm

Because you are writing bytes to the Response object, I doubt you can. I would recommend just writing a function instead of using a handler.

Swayam231 23-May-13 14:34pm

can u please give an example for that?? using the above data

ZurdoDev 23-May-13 14:38pm

Is button1_click just supposed to fill in values? Can you give more details? Based on your other post it looks like you are getting other values back (name, account, etc) so have a function that fills all that in for you.

Swayam231 23-May-13 14:40pm

<pre>
protected void Button1_Click(object sender, EventArgs e)
{

string strConn = "Data Source=SWAYAM;Initial Catalog=Swayam;Integrated Security=SSPI; ";
SqlConnection con = new SqlConnection(strConn);
con.Open();
string st = "select top 1 name,author,price,details from image3 order by Row_id desc";
SqlCommand cmd = new SqlCommand(st, con);
SqlDataReader sdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
string name = "";
string author = "";
string price = "";
string details = "";
if (sdr.Read())
{
name = sdr["name"].ToString();
author = sdr["author"].ToString();
price = sdr["price"].ToString();
details = sdr["details"].ToString();
}

Label1.Text = name;
Label2.Text = price;
Label3.Text = author;
Label4.Text = details;
}

}
</pre>
Here's wht is getting me my values from db

ZurdoDev 23-May-13 15:05pm

Right, so you are getting these values from the db and you are also getting your image from the db. Seems like you should just do it this way, all at once. In my experience, custom handlers are not use very often. It seems overkill to have a handler to do this.

Swayam231 24-May-13 3:09am

you were mentioning abt some function here... can u name the function please?

ZurdoDev 24-May-13 8:21am

It would be one that you write.

2 solutions

Solution 2

There is no way to get multiple images from database using image handler , try store imagepath in db and image in folder.. It 100% works.

Posted 10-Oct-13 9:29am

NitishBharadwaj

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Swayam231 · Accepted Answer · 2013-05-24T08:35:00

So it seems bit difficult to solve but still i have done it myself:
Here are the working codes:

Handler:

//retrieving multiple images based on their Row_id

public class imHandler : IHttpHandler 
{
    public void ProcessRequest(HttpContext context)
    {
        string strConn = "//connection string ";
        SqlConnection con = new SqlConnection(strConn);
        con.Open();
        if (context.Request.QueryString["pid"] != null)
        {

            string ID = context.Request.QueryString["pid"].ToString();
            int pid = Convert.ToInt32(ID);
            //the command will retrieve images based on rows

            string st = "select image1 from table1 where Row_id=@row";
            SqlCommand cmd = new SqlCommand(st, con);
            cmd.Parameters.Add("@row", SqlDbType.Int).Value = pid;
            cmd.Prepare();
            SqlDataReader dr = cmd.ExecuteReader();
            dr.Read();
            try
            {
                context.Response.ContentType = "jpeg";//use ur image type
                context.Response.BinaryWrite((byte[])dr["image1"]);
                dr.Close();

            }

            catch (Exception ex)
            {
                throw ex;
            }
            finally
            {
                con.Close();
            }
        }
    }
    public bool IsReusable 
    {
        get {
                return false;
            }
    }

}

And here's how to call the images, i have written them in page_
load event u can use btn_click also!!!
Take image controls in ur page and write the codes below:

 protected void Page_Load(object sender, EventArgs e)
    {
        image1.imageurl="handlername.ashx?pid=1";
        image2.imageurl="handler.ashx?pid=2";
       // and so on......
      }
the pid here is the variable u have declared in the handler