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asp.net图片上传及生成缩略图

2012年10月27日 ⁄ 综合 ⁄ 共 5070字 ⁄ 字号 评论关闭
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.IO;
using System.Text;
using System.Drawing;
/// <summary>
/// 图片上传类
/// </summary>
public class uploadImg
{
    public uploadImg() { }
    /*调用: 
    只要先实例化类之后,设置想要的属性。 
    UpLoadIMG(this.fileupload1) 
    输入文件上传控件的ID作为参数就可以了。 
    */
     private static string _MSG;
     private string OFullName;// 保存时的完整路径.原图
     private string TFullName;// 保存时的完整路径.缩略图
     private static string _OFileName;// 保存时的图片名称.原图
     private string TFileName;// 保存时的图片名称.缩略图
     //private string _tfullname = "0";
     //private string _ofilename = "0";
     //private string _tfilename = "0";
     private string _tprefix = "small_";
     private int _limitwidth = 3072;
     private int _limitheight = 2304;
     private int _twidth = 100;
     private int _theight = 100;
     private int _size = 3000000;
     private bool _israte;
     private bool _iscreate;
     private string _path = "upload";
     /// <summary>
     /// 信息
     /// </summary>
     public static string MSG
     {
         get { return _MSG; }
         set { _MSG = value; }
     }
    /// <summary>
    /// 缩略图前缀
    /// </summary>
     public string TPrefix
     {
         get { return _tprefix; }
         set { _tprefix = value; }
     }
     /// <summary>
     /// 原图最大宽度
     /// </summary>
     public int LimitWidth
     {
         get { return _limitwidth; }
         set { _limitwidth = value; }
     }
     /// <summary>
     /// 原图最大高度
     /// </summary>
     public int LimitHeight
     {
         get { return _limitheight; }
         set { _limitheight = value; }
     }
     /// <summary>
     /// 缩略图最大宽度
     /// </summary>
     public int TWidth
     {
         get { return _twidth; }
         set { _twidth = value; }
     }
     /// <summary>
     /// 缩略图最大高度
     /// </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>
     /// 是否生成缩略图
     /// </summary>
     public bool IsCreate
     {
         get { return _iscreate; }
         set { _iscreate = value; }
     }
     /// <summary>
     /// 存放图片的文件夹名称
     /// </summary>
     public string Path
     {
         get { return _path; }
         set { _path = value; }
     }
    /// <summary>
    /// 原图名称
    /// </summary>
     public static string OFileName
     {
         get { return _OFileName; }
         set { _OFileName = 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upload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 = "文件格式不正确,只能为jpeg,jpg,gif,png或bmp !";
                 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 =string.Format("图片的大小应小于 {0} M!",Math.Round(_size/1024.0/1024.0,2));
                 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 =string.Format("图片尺寸应小于{0}*{1}",_limitwidth,this._limitheight);
                 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.HighQualityBicubic; //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(999999999).ToString();//生成9位随机数字
             //格式化日期作为文件名
             string oStringTime = string.Format("{0:yyyyMMddHHmmss}", DateTime.Now);
             OFileName =oStringTime + oStringRandom + filename;
             TFileName = TPrefix + oStringTime + oStringRandom + filename;
             string SavePath = HttpContext.Current.Server.MapPath("~") + "\\" + Path + "\\";
             if (!Directory.Exists(SavePath))
             {
                 Directory.CreateDirectory(SavePath);//在根目录下建立文件夹
             }
             OFullName = SavePath + OFileName;
             TFullName = SavePath + 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);
                             if(IsCreate)tImage.Save(TFullName, System.Drawing.Imaging.ImageFormat.Jpeg);
                             break;
                         }
                     case ".gif":
                         {
                             oImage.Save(OFullName, System.Drawing.Imaging.ImageFormat.Gif);
                             if (IsCreate) tImage.Save(TFullName, System.Drawing.Imaging.ImageFormat.Gif);
                             break;
                         }
                     case ".png":
                         {
                             oImage.Save(OFullName, System.Drawing.Imaging.ImageFormat.Png);
                             if (IsCreate) tImage.Save(TFullName, System.Drawing.Imaging.ImageFormat.Png);
                             break;
                         }
                     case ".bmp":
                         {
                             oImage.Save(OFullName, System.Drawing.Imaging.ImageFormat.Bmp);
                             if (IsCreate)tImage.Save(TFullName, System.Drawing.Imaging.ImageFormat.Bmp);
                             break;
                         }
                 }
                 MSG = "图片上传成功!";
                 //保存路径+完整文件名
                 string _SavePath = "/" + Path + "/";
                 OFullName = _SavePath + OFileName;
                 TFullName = _SavePath + TFileName;
                 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;
         }
     }
}

 

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