自己写了一个上传类，实现了常用的功能

 

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.Drawing;

/**//// <summary>
/// UploadFile 的摘要说明
/// </summary>
public class UploadFile
...{
    public UploadFile()
    ...{
        //检查根目录，如果没有Temp,TempReadyImg,TempReadyImg1，那么就创建它


        string strPath = HttpContext.Current.Server.MapPath("~/");

        if (!File.Exists(strPath + "Temp"))
        ...{
            FileStream  fs = File.Create(strPath + "Temp");
            //File.OpenRead(strPath + "Temp");
            fs.Close();
            fs.Dispose();
        }
        if (!File.Exists(strPath + "TempReadyImg"))
        ...{
            FileStream fs = File.Create(strPath + "TempReadyImg");
            //File.OpenRead(strPath + "TempReadyImg");
            fs.Close();
            fs.Dispose();
        }
        if (!File.Exists(strPath + "TempReadyImg1"))
        ...{
            FileStream fs = File.Create(strPath + "TempReadyImg1");
            //File.OpenRead(strPath + "TempReadyImg1");
            fs.Close();
            fs.Dispose();
        }
    }

    /**//// <summary>
    /// 获得文件的二进制数据流
    /// </summary>
    /// <param name="filePathFile">需要压制的文件路径和名称全字符串</param>
    /// <returns>文件二进制流的指针</returns>
    public byte[] GetTempReadyImgData(string filePathName)
    ...{
        FileStream fs = new FileStream(filePathName, FileMode.Open);
        int nLength = (int)fs.Length;
        byte[] fileData = new byte[nLength];
        fs.Read(fileData, 0, nLength);
        fs.Close();
        return fileData;
    }

     /**//// <summary>
    /// 绑定上传图片到临时文件 
    /// </summary>
    /// <param name="fileUpload">上传图片的控件</param>
    /// <param name="imgPhoto">显示图片的Image控件的引用</param>
    /// <param name="clientScriptManager">当前页的客户端脚本管理器</param>
    /// <return>返回产生的临时文件的文件名(包括路径)</return>
    public string BindUploadPhotoToImage(FileUpload fileUpload, ref System.Web.UI.WebControls.Image imgPhoto, string folder, ClientScriptManager clientScriptManager)
    ...{
        string PathFilename = string.Empty;
        if (fileUpload.HasFile)
        ...{
            string Folder = folder;
            PathFilename = UploadPhotoFile(fileUpload, Folder, clientScriptManager);
        }
        else
        ...{                   
            if (!clientScriptManager.IsStartupScriptRegistered("NoFile"))
                clientScriptManager.RegisterStartupScript(GetType(), "NoFile", "alert('请指定上传的文件！')", true);
        }
        imgPhoto.ImageUrl=PathFilename;

        return PathFilename;
    }

    /**//// <summary>
    /// 绑定上传图片并且保存为临时文件 
    /// </summary>
    /// <param name="fileUpload">上传图片的控件</param>
    /// <param name="imgPhoto">显示图片的Image控件的引用</param>
    /// <param name="clientScriptManager">当前页的客户端脚本管理器</param>
    /// <return>返回产生的临时文件的文件名(包括路径)</return>
    public string BindUploadPhotoToImage(FileUpload fileUpload, ref System.Web.UI.WebControls.Image imgPhoto, ClientScriptManager clientScriptManager)
    ...{
        string Folder = @"../TempImg/";
        string PathFilename = BindUploadPhotoToImage(fileUpload, ref imgPhoto, Folder ,clientScriptManager);

        return PathFilename;
    }

    /**//// <summary>
    /// 将文件上传到指定的临时文件夹并产生一个临时文件
    /// </summary>
    /// <param name="fileUpload">上传控件的实例</param>
    /// <param name="folder">上传的文件夹</param>
    /// <param name="clientScriptManager">当前页的客户端脚本管理器</param>
    /// <returns>返回上传图片的临时文件名称(包括路径)</returns>
    public string UploadPhotoFile(FileUpload fileUpload, string folder, ClientScriptManager clientScriptManager)
    ...{
        FileUpload FileUpload = fileUpload;
        string Filename = FileUpload.FileName;
        string Folder = folder;

        string strFileName = string.Empty;
        string strPath = string.Empty;
        if (ValidatePhotoFileType(Filename) == true)
        ...{
            try
            ...{
                strFileName = Guid.NewGuid().ToString();
                strPath = HttpContext.Current.Server.MapPath(Folder);
                FileUpload.PostedFile.SaveAs(strPath + strFileName);
            }
            catch
            ...{
                if (!clientScriptManager.IsStartupScriptRegistered("UploadFail"))
                    clientScriptManager.RegisterStartupScript(this.GetType(), "UploadFail", "alert('文件上传失败!')", true);
            }
        }
        else
        ...{
            if (!clientScriptManager.IsStartupScriptRegistered("TypeError"))
                clientScriptManager.RegisterStartupScript(this.GetType(), "TypeError", "alert('只允许上传gif,png,jpeg,jpg文件!')", true);
        }

        return strPath + strFileName;
    }

    /**//// <summary>
    /// 将文件上传到指定的临时文件夹并产生一个临时文件
    /// </summary>
    /// <param name="fileUpload">上传控件的实例</param>
    /// <param name="folder">上传的文件夹</param>
    /// <param name="allowedExtentions">允许上传的类型</param>
    /// <param name="clientScriptManager">当前页的客户端脚本管理器</param>
    /// <returns>返回上传图片的临时文件名称(包括路径)</returns>
    public string UploadTypedFile(FileUpload fileUpload, string folder, string[] allowedExtentions, ClientScriptManager clientScriptManager)
    ...{
        FileUpload FileUpload = fileUpload;
        string Filename = FileUpload.FileName;
        string Folder = folder;
        string[] AllowedExtentions = allowedExtentions;
        string strFileName = string.Empty;
        string strPath = string.Empty;
        if (ValidateFileType(Filename, AllowedExtentions) == true)
        ...{
            try
            ...{
                strFileName = Guid.NewGuid().ToString();
                strPath = HttpContext.Current.Server.MapPath(Folder);
                FileUpload.PostedFile.SaveAs(strPath + strFileName);
            }
            catch
            ...{
                if (!clientScriptManager.IsStartupScriptRegistered("UploadFail"))
                    clientScriptManager.RegisterStartupScript(this.GetType(), "UploadFail", "alert('文件上传失败!')", true);
            }
        }
        else
        ...{
            string FileTypes = string.Empty;
            int count = AllowedExtentions.Length;
            if (count == 0)
            ...{
                if (!clientScriptManager.IsStartupScriptRegistered("TypeError"))
                    clientScriptManager.RegisterStartupScript(this.GetType(), "TypeError", "alert('请指定上传的类型!')", true);
            }
            else
            ...{
                for (int i = 0; i < count; i++)
                ...{
                    FileTypes = FileTypes + AllowedExtentions[i];
                }
                if (!clientScriptManager.IsStartupScriptRegistered("TypeError"))
                    clientScriptManager.RegisterStartupScript(this.GetType(), "TypeError", "alert('只允许上传'" + FileTypes + "'文件!')", true);
            }
        }

        return strPath + strFileName;
    }

    /**//// <summary>
    /// 判断上传的文件类型
    /// </summary>
    /// <param name="filename">需要判断的文件名称</param>
    /// <param name="allowedExtentions">允许的文件后缀名</param>
    /// <returns>1表示正确, 0表示错误</returns>
    public bool ValidateFileType(string filename, string[] allowedExtentions)
    ...{
        string Filename = filename;
        //---判断文件名是否正确---
        bool isCorrect = false;
        String fileExtension = System.IO.Path.GetExtension(Filename).ToLower();
        String[] AllowedExtensions =  allowedExtentions;
        for (int i = 0; i < AllowedExtensions.Length; i++)
        ...{
            if (fileExtension == AllowedExtensions[i])
            ...{
                isCorrect = true;
            }
        }
        return isCorrect;
    }

    /**//// <summary>
    /// 判断上传的是否图片类型的文件
    /// </summary>
    /// <param name="filename">需要判断的文件名称</param>
    /// <returns>1表示正确, 0表示错误</returns>
    public bool ValidatePhotoFileType(string filename)
    ...{
        string Filename = filename;
        String[] AllowedExtensions = ...{ ".gif", ".png", ".jpeg", ".jpg" };
        bool isCorrect = ValidateFileType(Filename, AllowedExtensions);
        return isCorrect;
    }

    /**//// <summary>
    /// 删除已经存在的文件
    /// </summary>
    /// <param name="filename">文件的文件名和绝对路径</param>
    /// <returns>1-删除成功, 0-删除失败</returns>
    public bool DeleteExistFile(string filename)
    ...{
        bool isDelete = false;
        if (File.Exists(filename))
        ...{
            try
            ...{
                File.Delete(filename);
                isDelete = true;
            }
            catch
            ...{
                isDelete = false;
            }
        }
        else
        ...{
            isDelete = false;
        }

        return isDelete;
    }
}