c#图片生成缩略图，保持最高清的图片

来源：互联网发布：淘宝付款流程编辑：程序博客网时间：2024/05/02 12:15

1.生成缩略图的主要代码

        /// <summary>        /// 图片显示成缩略图        /// </summary>        /// <param name="sourcePath" >图片原路径</param>        /// <param name="newPath">生成的缩略图新路径</param>        /// <param name="width">生成的缩略图宽度</param>        /// <param name="height">生成的缩略图高度</param>        public static void MakeThumbnail(string sourcePath, string newPath, int width, int height)        {            sourcePath = System.Web.HttpContext.Current.Server.MapPath(sourcePath);            newPath = System.Web.HttpContext.Current.Server.MapPath(newPath);            System.Drawing.Image ig = System.Drawing.Image.FromFile(sourcePath);            int towidth = width;            int toheight = height;            int x = 0;            int y = 0;            int ow = ig.Width;            int oh = ig.Height;            if ((double)ig.Width / (double)ig.Height > (double)towidth / (double)toheight)            {                oh = ig.Height;                ow = ig.Height * towidth / toheight;                y = 0;                x = (ig.Width - ow) / 2;            }            else            {                ow = ig.Width;                oh = ig.Width * height / towidth;                x = 0;                y = (ig.Height - oh) / 2;            }            System.Drawing.Image bitmap = new System.Drawing.Bitmap(towidth, toheight);            System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap);            g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;            g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;            g.Clear(System.Drawing.Color.Transparent);            g.DrawImage(ig, new System.Drawing.Rectangle(0, 0, towidth, toheight), new System.Drawing.Rectangle(x, y, ow, oh), System.Drawing.GraphicsUnit.Pixel);            try            {                bitmap.Save(newPath, System.Drawing.Imaging.ImageFormat.Jpeg);            }            catch (Exception ex)            {                throw ex;            }            finally            {                ig.Dispose();                bitmap.Dispose();                g.Dispose();            }        }

2.具体操作流程
1.` protected void Page_Load(object sender, EventArgs e)
{
if (File.Exists(Server.MapPath(“现有图片路径”.ToString())))//判断现有图片路径是否存在
{
S_ImageHelper.MakeThumbnail(“现有图片路径”.ToString(), “新建缩略图路径”, 275, 254);
}

        Response.Write("成功");}`

3。显示成功，则缩略图生成好了，去看看你的新建路径里面是否又该图片吧

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