asp.net : A generic error occurred in GDI+

I create an asp.net 4.0 web application which has a web service for uploading images. I am uploading images by sending the image in form of Base64 string from my mobile app to the web service.

Following is my code:

public string Authenticate(string username, string password, string fileID, string imageData)
    {
        Dictionary<string, string> responseDictionary = new Dictionary<string, string>();
        bool isAuthenticated = true; // Set this value based on the authentication logic

        try
        {
            if (isAuthenticated)
            {
                UploadImage(imageData);

                string result = "success";
                var message = "Login successful";

                responseDictionary["status"] = result;
                responseDictionary["message"] = message;
            }
        }
        catch (Exception ex)
        {

            responseDictionary["status"] = ex.Message;
            responseDictionary["message"] = ex.StackTrace;
        }

        return new JavaScriptSerializer().Serialize(responseDictionary);
    }

    private void UploadImage(string uploadedImage)
    {
        // Convert Base64 String to byte[]
        byte[] imageBytes = Convert.FromBase64String(uploadedImage);
        MemoryStream ms = new MemoryStream(imageBytes, 0, imageBytes.Length);

        System.Drawing.Bitmap bitmap = (System.Drawing.Bitmap)Image.FromStream(ms);

        string uploadPath = Server.MapPath("..\uploads\") + DateTime.Now.Ticks.ToString() + ".jpeg";
        ms.Close();

        bitmap.Save(uploadPath, System.Drawing.Imaging.ImageFormat.Jpeg);
        bitmap.Dispose();
    }

This code was working fine on my local ASP.NET development server and I was able to see the uploaded image in my “uploads” directory. However, after transferring the code to the FTP directory, I am now getting the following error:

A generic error occurred in GDI+

I have checked that the upload directory has proper permission by creating a dummy .aspx page and creating a text file on page_load, and it works fine.

Even after doing google search, I was not able to solve this problem. Can anybody help me fixing this?

Thanks a lot in advance.

Answers:

Thank you for visiting the Q&A section on Magenaut. Please note that all the answers may not help you solve the issue immediately. So please treat them as advisements. If you found the post helpful (or not), leave a comment & I’ll get back to you as soon as possible.

Method 1

Instead of writing directly to files, save your bitmap to a MemoryStream and then save the contents of the stream to disk. This is an old, known issue and, frankly, I don’t remember all the details why this is so.

 MemoryStream mOutput = new MemoryStream();
 bmp.Save( mOutput, ImageFormat.Png );
 byte[] array = mOutput.ToArray();

 // do whatever you want with the byte[]

In your case it could be either

private void UploadImage(string uploadedImage)
{
    // Convert Base64 String to byte[]
    byte[] imageBytes = Convert.FromBase64String(uploadedImage);

    string uploadPath = Server.MapPath("..\uploads\") + DateTime.Now.Ticks.ToString() + ".jpeg";

    // store the byte[] directly, without converting to Bitmap first 
    using ( FileStream fs = File.Create( uploadPath ) )
    using ( BinaryWriter bw = new BinaryWriter( fs ) )
       bw.Write( imageBytes );
}

or

private void UploadImage(string uploadedImage)
{
    // Convert Base64 String to byte[]
    byte[] imageBytes = Convert.FromBase64String(uploadedImage);
    MemoryStream ms = new MemoryStream(imageBytes, 0, imageBytes.Length);

    System.Drawing.Bitmap bitmap = (System.Drawing.Bitmap)Image.FromStream(ms);

    string uploadPath = Server.MapPath("..\uploads\") + DateTime.Now.Ticks.ToString() + ".jpeg";
    ms.Close();

    // convert to image first and store it to disk
    using ( MemoryStream mOutput = new MemoryStream() )
    {  
        bitmap.Save( mOutput, System.Drawing.Imaging.ImageFormat.Jpeg);
        using ( FileStream fs = File.Create( uploadPath ) )
        using ( BinaryWriter bw = new BinaryWriter( fs ) )
            bw.Write( mOutput.ToArray() );
    }
}

Method 2

Furthermore I think it’s worth pointing out that when MemoryStream is used, stream must always be closed and save method MUST be called before the stream closure

 byte[] byteBuffer = Convert.FromBase64String(Base64String);
 MemoryStream memoryStream = new MemoryStream(byteBuffer);
 memoryStream.Position = 0;
 Bitmap bmpReturn = (Bitmap)Bitmap.FromStream(memoryStream);
 bmpReturn.Save(PicPath, ImageFormat.Jpeg);
 memoryStream.Close();

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0