一个好用的C#上传类!

using  System;
using  System.Web.UI;
using  System.IO;

namespace  wapmanage
{
    /**//// <summary>
    /// Upload 的摘要说明。
    /// </summary>
    public class Upload : System.Web.UI.Page
    {
        public Upload(){}

        public string UploadFile(string filePath,int maxSize,string[] fileType,System.Web.UI.HtmlControls.HtmlInputFile TargetFile)
        {
            string Result = "UnDefine";
            bool typeFlag = false;
            string FilePath = filePath;
            int MaxSize = maxSize;
            string strFileName,strNewName,strFilePath;
            if (TargetFile.PostedFile.FileName=="")
            {
                return "FILE_ERR";
            }
            strFileName = TargetFile.PostedFile.FileName;
            TargetFile.Accept = "*/*";
            strFilePath = FilePath;
            if (Directory.Exists(strFilePath)==false)
            { 
                Directory.CreateDirectory(strFilePath);
            }
            FileInfo myInfo=new FileInfo(strFileName);  
            string strOldName=myInfo.Name;
            strNewName=strOldName.Substring(strOldName.Length-3,3); 
            strNewName = strNewName.ToLower();
            if( TargetFile.PostedFile.ContentLength <= MaxSize)
            {
                for(int i = 0;i<=fileType.GetUpperBound(0);i++)
                {
                    if (strNewName.ToLower() == fileType[i].ToString()){typeFlag = true;break;}
                }
                if(typeFlag)
                {  
                    string strFileNameTemp = GetUploadFileName();
                    string strFilePathTemp = strFilePath ;
                    strOldName = strFileNameTemp + "." +strNewName;     
                    strFilePath=strFilePath + "\\" + strOldName;    
                    TargetFile.PostedFile.SaveAs(strFilePath);
                    Result = strOldName;
                    TargetFile.Dispose();
                }
                else
                {
                    return "TYPE_ERR";
                }
            }
            else
            {
                return "SIZE_ERR";
            }
            return(Result);
        }

        public string UploadFile(string filePath,int maxSize,string[] fileType, string filename, System.Web.UI.HtmlControls.HtmlInputFile TargetFile)
        {
            string Result = "UnDefine";
            bool typeFlag = false;
            string FilePath = filePath;
            int MaxSize = maxSize;
            string strFileName,strNewName,strFilePath;
            if (TargetFile.PostedFile.FileName=="")
            {
                return "FILE_ERR";
            }
            strFileName = TargetFile.PostedFile.FileName;
            TargetFile.Accept = "*/*";
            strFilePath = FilePath;
            if (Directory.Exists(strFilePath)==false)
            { 
                Directory.CreateDirectory(strFilePath);
            }
            FileInfo myInfo=new FileInfo(strFileName);  
            string strOldName=myInfo.Name;
            strNewName=strOldName.Substring(strOldName.Length-3,3); 
            strNewName = strNewName.ToLower();
            if( TargetFile.PostedFile.ContentLength <= MaxSize)
            {
                for(int i = 0;i<=fileType.GetUpperBound(0);i++)
                {
                    if (strNewName.ToLower() == fileType[i].ToString()){typeFlag = true;break;}
                }
                if(typeFlag)
                {  
                    string strFileNameTemp = filename;
                    string strFilePathTemp = strFilePath ;
                    strOldName = strFileNameTemp + "." +strNewName;     
                    strFilePath=strFilePath + "\\" + strOldName;    
                    TargetFile.PostedFile.SaveAs(strFilePath);
                    Result = strOldName;
                    TargetFile.Dispose();
                }
                else
                {
                    return "TYPE_ERR";
                }
            }
            else
            {
                return "SIZE_ERR";
            }
            return(Result);
        }

        private string GetUploadFileName()
        {
            string Result = "";
            DateTime time = DateTime.Now;   
            Result += time.Year.ToString() + FormatNum(time.Month.ToString(),2) + FormatNum(time.Day.ToString(),2) + FormatNum(time.Hour.ToString(),2) + FormatNum(time.Minute.ToString(),2) + FormatNum(time.Second.ToString(),2)  + FormatNum(time.Millisecond.ToString(),3) ;
            return(Result);
        }

        public string FormatNum(string Num,int Bit)
        {            
            int L;
            L = Num.Length;
            for(int i = L ;i < Bit ;i++)
            {
                Num = "0" + Num;
            }
            return(Num);
        }

    }
}

 调用:

   //创建给类别的图片保存目录
   var path
    path = "C:\temp\";
    if (!Directory.Exists(path))
    {
     Directory.CreateDirectory(path);
    }
    
    if(this.file.PostedFile.FileName != "")
    {
     string[] filetype = new string[]{"jpg","gif","png","JPG","GIF","PNG"};
     filename = new Upload().UploadFile(path , 204800, filetype, file);
    }