image resize asp.net helst i class

Du fyrer bare løs hvis der skulle komme nogen spørgsmål ... men måske du skulle starte førend spørgsmålet kom :-)

Du skal nok i hvert fald have fat i klasserne:
Image og Bitmap ...

Sakset fra mit eget bibliotek:



Eksemple på brug:

Hvordan du kan resize et billede.
Her gemmer den i jpeg, men det kan man jo bare lave dynamisk, hvis den skal gemme i andre formater, f.eks. samme som der indlæses fra.

public static void MakeThumbnail(string picture, string destination)
        {
            MakeThumbnail(picture, destination, 280);
        }
        public static void MakeThumbnailFromStream(Stream sr, string destination, int widthPicture)
        {
            System.Drawing.Bitmap image = new System.Drawing.Bitmap(sr);

            int modulus = image.Width / widthPicture;
            int width = image.Width;
            int height = image.Height;
            //image.Dispose();
            //image = null;
            if (modulus > 0)
            {
                width = width / modulus;
                height = height / modulus;
            }
            System.Drawing.Image imageThumb = image.GetThumbnailImage(width, height, null, new IntPtr());
            EncoderParameter qualityParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, (long)10000);
            EncoderParameters encoderParams = new EncoderParameters(1);
            encoderParams.Param[0] = qualityParam;

            if (File.Exists(destination))
            {
                File.Delete(destination);
            }
            ImageCodecInfo ci = GetEncoder("image/jpeg");
            imageThumb.Save(destination, ci, encoderParams);
        }
        public static void MakeThumbnail(string picture, string destination, int widthPicture)
        {
            //System.Drawing.Image image = System.Drawing.Image.FromFile(picture);
            System.Drawing.Bitmap image = new System.Drawing.Bitmap(picture, false);

            int modulus = image.Width / widthPicture;
            int width = image.Width;
            int height = image.Height;
            //image.Dispose();
            //image = null;
            if (modulus > 0)
            {
                width = width / modulus;
                height = height / modulus;
            }
            System.Drawing.Image imageThumb = image.GetThumbnailImage(width, height, null, new IntPtr());
            EncoderParameter qualityParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, (long)100);

            EncoderParameters encoderParams = new EncoderParameters(1);
            encoderParams.Param[0] = qualityParam;

            if (File.Exists(destination))
            {
                File.Delete(destination);
            }
            ImageCodecInfo ci = GetEncoder("image/jpeg");
            imageThumb.Save(destination, ci, encoderParams);
        }
        public static ImageCodecInfo GetEncoder(string mimeType)
        {

            ImageCodecInfo[] encoders = ImageCodecInfo.GetImageDecoders();

            for (int i = 0; i < encoders.Length; ++i)

                if (encoders[i].MimeType == mimeType)

                    return encoders[i];

            return null;

        }