图片上传自动生成大图小图 图片大小计算

        创建大图小图

void CreatBSimg(string extension,string path,string filename,string imgs)        {

            #region 得到图片尺寸            int imgWidth = 0;            int imgHeight = 0;            string[] imgExtension = new string[] { ".jpg", ".gif", ".png", ".bmp", ".jpeg" };            foreach (string item in imgExtension)            {                if (item == extension)                {                    System.Drawing.Image img = System.Drawing.Image.FromFile(imgs);                    imgWidth = img.Width;                    imgHeight = img.Height;

                    #region 新增 用于同时保存大图,和缩略图

                    //设置指定大小的上传                    UploadImageFixedSize(img, path + "\\T" + filename, 100, 100);                    //设置指定大小的上传                    UploadImageFixedSize(img, path + "\\B" + filename, 800, 600);                    #endregion

                    img.Dispose();                }            }            #endregion        }

保存图片        public void UploadImageFixedSize(System.Drawing.Image image, string savePath, int width, int height)        {            Graphics g1 = null;            Bitmap tImage = null;            try            {

                int oWidth = image.Width;//原图宽度                 int oHeight = image.Height;//原图高度                int tWidth = width;//设置缩略图初始宽度                 int tHeight = height;//设置缩略图初始高度                 int outwidth = 0;                int outheight = 0;                ChangeImageSize(oWidth, oHeight, tWidth, tHeight, ref outwidth, ref outheight);

                tImage = new Bitmap(outwidth, outheight);                g1 = Graphics.FromImage(tImage);                g1.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;//设置高质量插值法                 g1.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;//设置高质量,低速度呈现平滑程度                 g1.Clear(Color.Transparent);//清空画布并以透明背景色填充                 g1.DrawImage(image, new Rectangle(0, 0, outwidth, outheight), new Rectangle(0, 0, oWidth, oHeight), GraphicsUnit.Pixel);

                //以JPG格式保存图片                 tImage.Save(savePath, System.Drawing.Imaging.ImageFormat.Png);

            }            catch (Exception ex)            {                           }            finally            {                //释放资源                 //image.Dispose();                g1.Dispose();                tImage.Dispose();            }        }

计算图片大小        public void ChangeImageSize(float imgWidth, float imgHeight, int width, int height, ref int outwidth, ref int outheight)        {            try            {                if (imgHeight > height || imgWidth > width)                {                    if (imgHeight / height > imgWidth / width)                    {                        imgWidth = height / imgHeight * imgWidth;                        imgHeight = height;                    }                    else                    {                        imgHeight = width / imgWidth * imgHeight;                        imgWidth = width;                    }                }                outwidth = Convert.ToInt32(imgWidth);                outheight = Convert.ToInt32(imgHeight);            }            catch (Exception ce)            {            }        }

转载于:https://www.cnblogs.com/wanheng/archive/2012/01/11/2319214.html