donstack donstack - 1 month ago 16
C# Question

A Generic error occured in GDI+ in Bitmap.Save method

I am working on to upload and same a thumnail copy of that image in a thumbnail forder.

I am using following link:

http://weblogs.asp.net/markmcdonnell/archive/2008/03/09/resize-image-before-uploading-to-server.aspx

but

newBMP.Save(directory + "tn_" + filename);


is causing exception "A generic error occurred in GDI+."

I have tried to give permission on folder, also tried to use a new separate bmp object when saving.

Edit:

protected void ResizeAndSave(PropBannerImage objPropBannerImage)
{
// Create a bitmap of the content of the fileUpload control in memory
Bitmap originalBMP = new Bitmap(fuImage.FileContent);

// Calculate the new image dimensions
int origWidth = originalBMP.Width;
int origHeight = originalBMP.Height;
int sngRatio = origWidth / origHeight;
int thumbWidth = 100;
int thumbHeight = thumbWidth / sngRatio;

int bannerWidth = 100;
int bannerHeight = bannerWidth / sngRatio;

// Create a new bitmap which will hold the previous resized bitmap
Bitmap thumbBMP = new Bitmap(originalBMP, thumbWidth, thumbHeight);
Bitmap bannerBMP = new Bitmap(originalBMP, bannerWidth, bannerHeight);

// Create a graphic based on the new bitmap
Graphics oGraphics = Graphics.FromImage(thumbBMP);
// Set the properties for the new graphic file
oGraphics.SmoothingMode = SmoothingMode.AntiAlias; oGraphics.InterpolationMode = InterpolationMode.HighQualityBicubic;

// Draw the new graphic based on the resized bitmap
oGraphics.DrawImage(originalBMP, 0, 0, thumbWidth, thumbHeight);

Bitmap newBitmap = new Bitmap(thumbBMP);
thumbBMP.Dispose();
thumbBMP = null;

// Save the new graphic file to the server
newBitmap.Save("~/image/thumbs/" + "t" + objPropBannerImage.ImageId, ImageFormat.Jpeg);

oGraphics = Graphics.FromImage(bannerBMP);
// Set the properties for the new graphic file
oGraphics.SmoothingMode = SmoothingMode.AntiAlias; oGraphics.InterpolationMode = InterpolationMode.HighQualityBicubic;

// Draw the new graphic based on the resized bitmap
oGraphics.DrawImage(originalBMP, 0, 0, bannerWidth, bannerHeight);
// Save the new graphic file to the server
bannerBMP.Save("~/image/" + objPropBannerImage.ImageId + ".jpg");


// Once finished with the bitmap objects, we deallocate them.
originalBMP.Dispose();

bannerBMP.Dispose();
oGraphics.Dispose();
}

Answer

When either a Bitmap object or an Image object is constructed from a file, the file remains locked for the lifetime of the object. As a result, you cannot change an image and save it back to the same file where it originated. http://support.microsoft.com/?id=814675

A generic error occurred in GDI+, JPEG Image to MemoryStream

Image.Save(..) throws a GDI+ exception because the memory stream is closed

http://alperguc.blogspot.in/2008/11/c-generic-error-occurred-in-gdi.html

EDIT:
just writing from memory...

save to an 'intermediary' memory stream, that should work

e.g. try this one - replace

    Bitmap newBitmap = new Bitmap(thumbBMP);
    thumbBMP.Dispose();
    thumbBMP = null;
    newBitmap.Save("~/image/thumbs/" + "t" + objPropBannerImage.ImageId, ImageFormat.Jpeg);

with something like:

string outputFileName = "...";
using (MemoryStream memory = new MemoryStream())
{
    using (FileStream fs = new FileStream(outputFileName, FileMode.Create, FileAccess.ReadWrite))
    {
        thumbBMP.Save(memory, ImageFormat.Jpeg);
        byte[] bytes = memory.ToArray();
        fs.Write(bytes, 0, bytes.Length);
    }
}