C#•2y ago

❔ Image is not being displayed On Azure

In an application we get images of pdf files from the database in the form of a byte[]. When you use the preview button it is to open a new tab and display that file. IN development it shows up fine but once it is deployed to Azure on app service, Its just a blank page with no URL or any thing. I am requesting help debugging it.

        protected void cppreview_Callback(object sender, CallbackEventArgsBase e)
        {
            using (var uow = new OriginationUow())
            {
                var id = new Guid(Convert.ToString(hdf_attchmentid.Get("attachmentid")));
                var file = uow.Attachments.GetAll().Where(o => o.InvoiceId == (id));

                foreach (var item in file)
                {
                    byte[] fileBytes = item.FileDetails;
                    var filename = item.DocName;

                    if (filename.EndsWith(".pdf"))
                    {

                        Session["PdfFile"] = fileBytes;
                        Session["PdfId"] = id;
                        _name = "View/Attachment/PdfFile.aspx";
                    }
                }

                cppreview.JSProperties["cpResult"] = _name;
            }
        }

        protected void cppreview_Callback(object sender, CallbackEventArgsBase e)
        {
            using (var uow = new OriginationUow())
            {
                var id = new Guid(Convert.ToString(hdf_attchmentid.Get("attachmentid")));
                var file = uow.Attachments.GetAll().Where(o => o.InvoiceId == (id));

                foreach (var item in file)
                {
                    byte[] fileBytes = item.FileDetails;
                    var filename = item.DocName;

                    if (filename.EndsWith(".pdf"))
                    {

                        Session["PdfFile"] = fileBytes;
                        Session["PdfId"] = id;
                        _name = "View/Attachment/PdfFile.aspx";
                    }
                }

                cppreview.JSProperties["cpResult"] = _name;
            }
        }

31 Replies

tropicOP•2y ago

Things that I have tried I tried to use this method but that just returns a loading screen

context.Response.Clear();
            context.Response.ContentType = "image/png";
            context.Response.BinaryWrite(_cachedBinaryResources[imageName]);
            context.Response.Flush();

context.Response.Clear();
            context.Response.ContentType = "image/png";
            context.Response.BinaryWrite(_cachedBinaryResources[imageName]);
            context.Response.Flush();

I also tried to use this method as well

protected void btnDisplayPdf_Click(object sender, EventArgs e)
        {
            using (var uow = new OriginationUow())
            {
                var id = new Guid(Convert.ToString(hdf_attchmentid.Get("attachmentid")));
                var file = uow.Attachments.GetAll().Where(o => o.InvoiceId == (id));

                foreach (var item in file)
                {
                    byte[] fileBytes = item.FileDetails;
                    var filename = item.DocName;

                    if (filename.EndsWith(".pdf"))
                    {
                        // Get the byte array representing the PDF content
                        byte[] pdfBytes = fileBytes;

                        // Convert the byte array to a Base64 string
                        string base64String = Convert.ToBase64String(pdfBytes);

                        // Create a data URL with the image/jpeg content type
                        string dataUrl = $"data:image/png;base64,{base64String}";

                        // Register a startup script to open the data URL in a new window or tab
                        string script = $"window.open('{dataUrl}');";
                        ScriptManager.RegisterStartupScript(this, GetType(), "OpenImageScript", script, true);
                    }
                }
                
            }
        }

protected void btnDisplayPdf_Click(object sender, EventArgs e)
        {
            using (var uow = new OriginationUow())
            {
                var id = new Guid(Convert.ToString(hdf_attchmentid.Get("attachmentid")));
                var file = uow.Attachments.GetAll().Where(o => o.InvoiceId == (id));

                foreach (var item in file)
                {
                    byte[] fileBytes = item.FileDetails;
                    var filename = item.DocName;

                    if (filename.EndsWith(".pdf"))
                    {
                        // Get the byte array representing the PDF content
                        byte[] pdfBytes = fileBytes;

                        // Convert the byte array to a Base64 string
                        string base64String = Convert.ToBase64String(pdfBytes);

                        // Create a data URL with the image/jpeg content type
                        string dataUrl = $"data:image/png;base64,{base64String}";

                        // Register a startup script to open the data URL in a new window or tab
                        string script = $"window.open('{dataUrl}');";
                        ScriptManager.RegisterStartupScript(this, GetType(), "OpenImageScript", script, true);
                    }
                }
                
            }
        }

For added context I did not develop this app and it was inherited from another programmer who ended with the company on bad terms so no support from the original.

tropicOP•2y ago

What is generated

tropicOP•2y ago

What is supposed to be there

Mayor McCheese•2y ago

I've not done webforms for some time, but imho you're abusing the aspx page and competing with page lifecycle issues, I'd try this as an ashx page for displaying the binary content.

tropicOP•2y ago

Fair, I just inherited this application from a dev that left on bad terms So no support there to explain what anything in this application is

Mayor McCheese•2y ago

Is there anything in commit history?

tropicOP•2y ago

So, he did have a git repo, but when we attained the code he left the zip file without the .git folder

Mayor McCheese•2y ago

Also what are you using in azure

tropicOP•2y ago

App Service So we are working with an app no documentation sadly and no commit history

Mayor McCheese•2y ago

Seriously? Wtf, I'm so sorry to hear that.

tropicOP•2y ago

Yeah it sucks

Mayor McCheese•2y ago

So app services are backed by an app service plan, do you know the app service plan sku/os? I'm not sure if you can easily change oS if it's not windows

tropicOP•2y ago

Os is windows

Mayor McCheese•2y ago

Ugh

tropicOP•2y ago

SKU would be the default Basic (B1) Yeah, I know xD

Mayor McCheese•2y ago

Sku won't help, but I figured on the off chance something doesn't work as expected on Linux with web forms.

tropicOP•2y ago

Yeah

Mayor McCheese•2y ago

Any log messages?

tropicOP•2y ago

I am trying this method

protected void preview_Callback(object sender, CallbackEventArgsBase e)
        {
            using (var uow = new OriginationUow())
            {
                var id = new Guid(Convert.ToString(hdf_attchmentid.Get("attachmentid")));
                var file = uow.Attachments.GetAll().Where(o => o.InvoiceId == (id));

                foreach (var item in file)
                {

                    byte[] fileBytes = item.FileDetails;
                    var filename = item.DocName;

                    if (filename.EndsWith(".pdf"))
                    {
                        // Assume that 'imageBytes' is your byte array containing the image data

                        // Convert the byte array to a Base64-encoded string
                        string base64String = Convert.ToBase64String(fileBytes);

                        // Generate the data URL with the Base64-encoded image
                        string imageUrl = $"data:image/png;base64,{base64String}";

                        // Use window.location to display the image in a new window or tab
                        ScriptManager.RegisterStartupScript(this, this.GetType(), "openImage", $"window.open('{imageUrl}')", true);

                        _name = "View/Attachment/PdfFile.aspx";
                    }

                    // cppreview.JSProperties["cpResult"] = _name;
                }
            }
        }

protected void preview_Callback(object sender, CallbackEventArgsBase e)
        {
            using (var uow = new OriginationUow())
            {
                var id = new Guid(Convert.ToString(hdf_attchmentid.Get("attachmentid")));
                var file = uow.Attachments.GetAll().Where(o => o.InvoiceId == (id));

                foreach (var item in file)
                {

                    byte[] fileBytes = item.FileDetails;
                    var filename = item.DocName;

                    if (filename.EndsWith(".pdf"))
                    {
                        // Assume that 'imageBytes' is your byte array containing the image data

                        // Convert the byte array to a Base64-encoded string
                        string base64String = Convert.ToBase64String(fileBytes);

                        // Generate the data URL with the Base64-encoded image
                        string imageUrl = $"data:image/png;base64,{base64String}";

                        // Use window.location to display the image in a new window or tab
                        ScriptManager.RegisterStartupScript(this, this.GetType(), "openImage", $"window.open('{imageUrl}')", true);

                        _name = "View/Attachment/PdfFile.aspx";
                    }

                    // cppreview.JSProperties["cpResult"] = _name;
                }
            }
        }

Nope, which is not helpful it puts the image there but its just black So i guess it doesnt see it as an issue

Mayor McCheese•2y ago

Are the databases the same?

tropicOP•2y ago

Yes they are

Mayor McCheese•2y ago

Hmm was thinking maybe it's just bad in prod

tropicOP•2y ago

Which is why I am VERY confused, I was like maybe the DB just got corrupted

Mayor McCheese•2y ago

Btw just glancing at code, I'm concerned about rce Remote code execution

tropicOP•2y ago

yeah, honestly was just trying to get something working and then move on If you had to display an image from a Byte[] in aspx how would you go about it, no code needed just a general overview

Mayor McCheese•2y ago

I'd use an ashx 🙂

tropicOP•2y ago

Darnit, thats gonna be a bit weird in this case

Mayor McCheese•2y ago

Iirc there is a webforms image control that can take a byte source, but I'm a decade out of date on webforms

tropicOP•2y ago

hmmm

Mayor McCheese•2y ago

Basically what you're doing now but with an image control https://stackoverflow.com/questions/39338359/asp-net-display-image-from-byte-array

string base64String = Convert.ToBase64String(arr, 0, arr.Length);
img.Src = "data:image/jpg;base64," + base64String;

string base64String = Convert.ToBase64String(arr, 0, arr.Length);
img.Src = "data:image/jpg;base64," + base64String;

That gets rid of all your window location and calling out specific views in, I'm assuming JavaScript.

Accord•2y ago

Was this issue resolved? If so, run /close - otherwise I will mark this as stale and this post will be archived until there is new activity.

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❔ Image is not being displayed On Azure