学步园

类代码~

public class UpLoadFiles : System.Web.UI.Page
{
    public UpLoadFiles()
    {
        //
        // TODO: 在此处添加构造函数逻辑
        //
    }

    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 ;
                    float strFileSize = TargetFile.PostedFile.ContentLength / 1024;
                    strOldName = strFileNameTemp + "." +strNewName;     
                    strFilePath=strFilePath + "\\" + strOldName;    
                    TargetFile.PostedFile.SaveAs(strFilePath);
                    Result = strOldName + "|" + strFileSize;
                    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);
    }
        
}

调用代码~

string path="";
path = Server.MapPath("路径");
if (!Directory.Exists(path)) 
{
    Directory.CreateDirectory(path);
}
if(this.file.PostedFile.FileName != "")
{
    string[] filetype = new string[]{"jpg","gif"};
    string filename = new UpLoadFiles().UploadFile(path, 1000000, filetype, file); //1000000单位是字节
}

可以对文件强制命名，也可以自动命名。