using System;using System.Web;using System.IO;using System.Web.UI;using System.Drawing;using System.Drawing.Imaging;using System.Web.UI.WebControls;using System.Web.UI.HtmlControls;public partial class PhotoCropper : System.Web.UI.Page{    //原图    private const string ORIG_SAMPLE_PHOTO_URL ="photos/2.jpg";    //裁剪图    private const string CROPPED_SAMPLE_PHOTO_URL = "photos/2Cropped.jpg"; protected void Page_Load(object sender, System.EventArgs e){        if (!Page.IsPostBack)        {            loadPhoto(ORIG_SAMPLE_PHOTO_URL);        }        else        {            loadPhoto(CROPPED_SAMPLE_PHOTO_URL);            btnCrop.Visible = !btnCrop.Visible;            btnReset.Visible = !btnReset.Visible;        }}    protected void loadPhoto(string url)     {        imgSample.ImageUrl = url;    }    protected void btnCrop_Click(object sender, EventArgs e)    {        int iWidth = Convert.ToInt16(width.Value);        int iHeight =  Convert.ToInt16(height.Value);        int iX =  Convert.ToInt16(x1.Value);        int iY =  Convert.ToInt16(y1.Value);        //用字节流读取        byte[] rawData = File.ReadAllBytes(Context.Server.MapPath(""+ORIG_SAMPLE_PHOTO_URL+""));        byte[] newImage = CropImageFile(rawData, iWidth, iHeight, iX, iY);          writeByteArrayToFile(newImage);    }    //重置    protected void btnReset_Click(object sender, EventArgs e)    {        Response.Redirect("PhotoCropper.aspx", true);    }    //字节数组换成图片文件

protected void writeByteArrayToFile(byte[] byteImage) {        using (BinaryWriter binWriter =        new BinaryWriter(File.Open(Context.Server.MapPath("" + CROPPED_SAMPLE_PHOTO_URL + ""), FileMode.Create)))        {            binWriter.Write(byteImage);        }    }    //裁剪    protected byte[] CropImageFile(byte[] imageFile, int targetW, int targetH, int targetX, int targetY)    {        MemoryStream imgMemoryStream = new MemoryStream();        System.Drawing.Image imgPhoto = System.Drawing.Image.FromStream(new MemoryStream(imageFile));        Bitmap bmPhoto = new Bitmap(targetW, targetH, PixelFormat.Format24bppRgb);        bmPhoto.SetResolution(72, 72);           Graphics grPhoto = Graphics.FromImage(bmPhoto);        grPhoto.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;        grPhoto.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;        grPhoto.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;        try        {            grPhoto.DrawImage(imgPhoto, new Rectangle(0, 0, targetW, targetH), targetX, targetY, targetW, targetH, GraphicsUnit.Pixel);            bmPhoto.Save(imgMemoryStream, System.Drawing.Imaging.ImageFormat.Jpeg);        }        catch (Exception e)        {            throw e;        }        finally        {            imgPhoto.Dispose();            bmPhoto.Dispose();            grPhoto.Dispose();        }        return imgMemoryStream.GetBuffer();    }    //转换图片成子节流

protected byteImage bytetry        using MemoryStream new MemoryStreamImageFormatcatch Exception throw return

}

本文转自曾祥展博客园博客，原文链接：http://www.cnblogs.com/zengxiangzhan/archive/2010/01/04/1638780.html，如需转载请自行联系原作者