急求缩略图方法

Question

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Answer 1

试试这个 
public static void MakeSmallImg(System.IO.Stream fromFileStream, string fileSaveUrl, Double templateWidth, Double templateHeight)
    {
        System.Drawing.Image myImage = System.Drawing.Image.FromStream(fromFileStream, true);
        System.Double newWidth = myImage.Width, newHeight = myImage.Height;
        if (myImage.Width > myImage.Height || myImage.Width == myImage.Height)
        {
            if (myImage.Width > templateWidth)
            {
                //宽按模版，高按比例缩放                newWidth = templateWidth;
                newHeight = myImage.Height * (newWidth / myImage.Width);
            }
        }
        //高大于模版的竖图
        else
        {
            if (myImage.Height > templateHeight)
            {
                //高按模版，宽按比例缩放                newHeight = templateHeight;
                newWidth = myImage.Width * (newHeight / myImage.Height);
            }
        }        System.Drawing.Size mySize = new Size((int)newWidth, (int)newHeight);
        System.Drawing.Image bitmap = new System.Drawing.Bitmap(mySize.Width, mySize.Height);
        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(Color.White);
        g.DrawImage(myImage, new System.Drawing.Rectangle(0, 0, bitmap.Width, bitmap.Height),
            new System.Drawing.Rectangle(0, 0, myImage.Width, myImage.Height),
            System.Drawing.GraphicsUnit.Pixel);        //保存缩略图        bitmap.Save(fileSaveUrl, System.Drawing.Imaging.ImageFormat.Jpeg);        g.Dispose();
        myImage.Dispose();
        bitmap.Dispose();
    }

Answer 2

http://www.wave12.com/web/home.asp缩略图水印组件wsImage3.5