Web pointing stick doesn’t shoot in reverse gear

Question

I have a web application into which I upload an image, the image is subsequently saved in the server temp folder and displayed through the web manipulator on the aspx page.

code for aspx:

<img src="PreviewImageQualityHandler.ashx" alt="Picture not loaded" runat="server" id="imagePreview" />

Code to upload the image and add a unique identifier to the session:

protected void uploadButton_Click(object sender, EventArgs e)
{
    if (FileUploadControl.FileName.EndsWith(".jpg") || FileUploadControl.FileName.EndsWith(".jpeg"))
    {
        string tempFileName = Path.GetTempFileName();
        FileUploadControl.SaveAs(tempFileName);
        Session["tempName"] = tempFileName;
        Response.Write(Session["tempName"]);
        fileName = FileUploadControl.FileName;
    }
    else
    {
        Response.Write("<script>alert('Please select a .jpg/.jpeg image to upload')</script>");
    }
}

Webmaster Code:

public class PreviewImageQualityHandler : IHttpHandler, IRequiresSessionState
{   
    public void ProcessRequest(HttpContext context)
    {
        try
        {
            if (context.Session.Count > 0)
            {
                string sessID = context.Session["tempName"].ToString();
                Bitmap bmp = (Bitmap)System.Drawing.Image.FromFile(sessID);
                context.Response.ContentType = "image/jpg";
                MemoryStream ms = new MemoryStream();
                bmp.Save(ms, ImageFormat.Bmp);
                byte[] b = ms.ToArray();
                context.Response.OutputStream.Write(b, 0, b.Length);
            }
        }
        catch(Exception ex) 
        { 

        }
    }

    public bool IsReusable
    {
        get
        {
            return false;
        }
    }
}

My problem is that the handler only starts when the image is first loaded. If I try to upload a new image, it never works.

If I delete everything that needs to be done with Session from the web handler, it starts with every postback, as it should be.

If someone can shed light on my problem, I will be extremely grateful!

Hi

Francis

Answer 1

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