asp.net图片上传公共类解决方法

//支持缩略图，是否等比缩放，指定像素缩放，限定上传大小，上传尺寸，图片存放路径，信息导出using System;using System.Data;using System.Configuration;using System.Web;using System.Web.Security;using System.Web.UI;using System.Web.UI.WebControls;using System.Web.UI.WebControls.WebParts;using System.Web.UI.HtmlControls;using System.Drawing;using System.IO;/// <summary>/// UploadIMG 的摘要说明/// </summary>public class UploadIMG{public UploadIMG(){//// TODO: 在此处添加构造函数逻辑//}private string _MSG;private string _ofullname;private string _tfullname;private string _ofilename;private string _tfilename;private int _limitwidth = 2048;private int _limitheight = 1536;private int _twidth = 100;private int _theight = 100;private int _size = 1000000;private bool _israte = true;private string _path = "UpdateFile";/// <summary>/// 信息/// </summary>public string MSG{get { return _MSG; }set { _MSG = value; }}/// <summary>/// 保存时的完整路径.原图/// </summary>public string OFullName{get { return _ofullname; }set { _ofullname = value; }}/// <summary>/// 保存时的完整路径.缩略图/// </summary>public string TFullName{get { return _tfullname; }set { _tfullname = value; }}/// <summary>/// 保存时的图片名称.原图/// </summary>public string OFileName{get { return _ofilename; }set { _ofilename = value; }}/// <summary>/// 保存时的图片名称.缩略图/// </summary>public string TFileName{get { return _tfilename; }set { _tfilename = value; }}/// <summary>/// 限定宽度/// </summary>public int LimitWidth{get { return _limitwidth; }set { _limitwidth = value; }}/// <summary>/// 限定高度/// </summary>public int LimitHeight{get { return _limitheight; }set { _limitheight = value; }}/// <summary>/// 缩略图宽度/// </summary>public int TWidth{get { return _twidth; }set { _twidth = value; }}/// <summary>/// 缩略图高度/// </summary>public int THeight{get { return _theight; }set { _theight = value; }}/// <summary>/// 文件大小/// </summary>public int Size{get { return _size; }set { _size = value; }}/// <summary>/// 是否成比例/// </summary>public bool IsRate{get { return _israte; }set { _israte = value; }}/// <summary>/// 存放图片的文件夹名称/// </summary>public string Path{get { return _path; }set { _path = value; }}/// <summary>/// 图片上传(默认:"等比压缩,限定上传尺寸2048*1536,缩略图尺寸100*100,限定上传大小1MB,存放在根目录UpdateFile中")/// </summary>/// <param name="UploadFile">文件上传控件</param>/// <returns>返回是否成功保存图片</returns>public bool UpLoadIMG(FileUpload UploadFile){if (UploadFile.HasFile)//检查是否已经选择文件{string filename = UploadFile.FileName.ToLower();int i = filename.LastIndexOf(".");filename = filename.Substring(i, filename.Length - i);if (!(filename == ".jpg" || filename == ".jpeg" || filename == ".gif" || filename == ".png" || filename == ".bmp")){MSG = "不受支持的类型,请重新选择!";return false;}//检查上传文件的格式是否有效if (UploadFile.PostedFile.ContentLength == 0 || UploadFile.PostedFile.ContentLength >= Size){MSG = "指定的文件大小不符合要求!";return false;}//检查图片文件的大小//生成原图 Stream oStream = UploadFile.PostedFile.InputStream;System.Drawing.Image oImage = System.Drawing.Image.FromStream(oStream);int owidth = oImage.Width; //原图宽度 int oheight = oImage.Height; //原图高度if (owidth > LimitWidth || oheight > LimitHeight){MSG = "超过允许的图片尺寸范围!";return false;}//检查是否超出规定尺寸if (IsRate){//按比例计算出缩略图的宽度和高度 if (owidth >= oheight){THeight = (int)Math.Floor(Convert.ToDouble(oheight) * (Convert.ToDouble(TWidth) / Convert.ToDouble(owidth)));//等比设定高度}else{TWidth = (int)Math.Floor(Convert.ToDouble(owidth) * (Convert.ToDouble(THeight) / Convert.ToDouble(oheight)));//等比设定宽度}}//生成缩略原图 Bitmap tImage = new Bitmap(TWidth, THeight);Graphics g = Graphics.FromImage(tImage);g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High; //设置高质量插值法 g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;//设置高质量,低速度呈现平滑程度 g.Clear(Color.Transparent); //清空画布并以透明背景色填充 g.DrawImage(oImage, new Rectangle(0, 0, TWidth, THeight), new Rectangle(0, 0, owidth, oheight), GraphicsUnit.Pixel);Random oRandom = new Random();string oStringRandom = oRandom.Next(9999).ToString();//生成4位随机数字//格式化日期作为文件名DateTime oDateTime = new DateTime();oDateTime = DateTime.Now;string oStringTime = oDateTime.ToString();oStringTime = oStringTime.Replace("-", "");oStringTime = oStringTime.Replace(" ", "");oStringTime = oStringTime.Replace(":", "");OFileName = "o" + oStringTime + oStringRandom + filename;TFileName = "t" + oStringTime + oStringRandom + filename;string oSavePath = HttpContext.Current.Server.MapPath("~") + "\\"+Path+"\\";if (!Directory.Exists(oSavePath)){Directory.CreateDirectory(oSavePath);//在根目录下建立文件夹}//保存路径+完整文件名OFullName = oSavePath + OFileName;TFullName = oSavePath + TFileName;//开始保存图片至服务器try{switch (filename){case ".jpeg":case ".jpg":{oImage.Save(OFullName, System.Drawing.Imaging.ImageFormat.Jpeg);tImage.Save(TFullName, System.Drawing.Imaging.ImageFormat.Jpeg);break;}case ".gif":{oImage.Save(OFullName, System.Drawing.Imaging.ImageFormat.Gif);tImage.Save(TFullName, System.Drawing.Imaging.ImageFormat.Gif);break;}case ".png":{oImage.Save(OFullName, System.Drawing.Imaging.ImageFormat.Png);tImage.Save(TFullName, System.Drawing.Imaging.ImageFormat.Png);break;}case ".bmp":{oImage.Save(OFullName, System.Drawing.Imaging.ImageFormat.Bmp);tImage.Save(TFullName, System.Drawing.Imaging.ImageFormat.Bmp);break;}}MSG = "图片上传成功!";return true;}catch (Exception ex){MSG = ex.Message;return false;}finally{//释放资源 oImage.Dispose();g.Dispose();tImage.Dispose();}}else{MSG = "请先选择需要上传的图片!";return false;}}}