最近学习了 C#实现文件上传与下载，现在分享给大家。
1、C#文件上传
创建MyUpload.htm页面，用于测试
< form name = "form1" method = "post" action = "UploadFile.aspx" id = "form1"
enctype = "multipart/form-data" >
< input type = "file" id = "txtFile" name = "picfile" /></ br >
< input type = "submit" value = "上传" />
</ form >
创建UploadFile.aspx文件，在UploadFile.aspx.cs键入如下代码：
Random rnd = new Random(); //产生随机数
private string _directory = @"/File/UploadFile" ; //目录
protected void Page_Load( object sender, EventArgs e)
{
try
{
if (RequestFilesCount > 0)
{
//判断文件大小
int length = RequestFiles[0]ContentLength;
if (length > 1048576)
{
ResponseWrite( "文件大于1M，不能上传" );
return ;
}
string type = RequestFiles[0]ContentType;
string fileExt = PathGetExtension(RequestFiles[0]FileName)ToLower();
//只能上传图片，过滤不可上传的文件类型
string fileFilt = "gif|jpg|php|jsp|jpeg|png|" ;
if (fileFiltIndexOf(fileExt) <= -1)
{
ResponseWrite( "对不起！请上传图片！！" );
return ;
}
else
{
string fileName = ServerMapPath(_directory) + "\\" + DateTimeNowToString( "yyyyMMddHHmmssfff" ) + rndNext(10, 99)ToString() + fileExt;
RequestFiles[0]SaveAs(fileName);
ResponseWrite( "上传成功！" );
}
}
}
catch
{
throw new Exception();
}
}
2 、C#文件下载
创建DownloadFile.aspx，在DownloadFile.aspx.cs键入如下方法：
/// <summary>
/// C#文件下载
/// </summary>
/// <param name="filename"></param>
public void MyDownload( string filename)
{
string path = ServerMapPath( "/File/" +filename);
if (!FileExists(path))
{
ResponseWrite( "对不起！文件不存在！！" );
return ;
}
SystemIOFileInfo file = new SystemIOFileInfo(path);
string fileFilt= "asp|aspx|php|jsp|ascx|config|asa|" ; //不可下载的文件，务必要过滤干净
string fileName = fileName;
string fileExt = fileNameSubstring(filenameLastIndexOf( "" ))Trim()ToLower();
if (fileFiltIndexOf(fileExt)!=-1)
{
ResponseWrite( "对不起！该类文件禁止下载！！" );
}
else
{
ResponseClear();
ResponseAddHeader( "Content-Disposition" , "attachment; filename=" + HttpUtilityUrlEncode(fileName));
ResponseAddHeader( "Content-Length" , fileLengthToString());
ResponseContentType = GetContentType(HttpUtilityUrlEncode(fileExt));
ResponseWriteFile(fileFullName);
ResponseEnd();
}
}
/// <summary>
/// 获取下载类型
/// </summary>
/// <param name="fileExt"></param>
/// <returns></returns>
public string GetContentType( string fileExt)
{
string ContentType;
switch (fileExt)
{
case "asf" :
ContentType = "video/x-ms-asf" ; break ;
case "avi" :
ContentType = "video/avi" ; break ;
case "doc" :
ContentType = "application/msword" ; break ;
case "zip" :
ContentType = "application/zip" ; break ;
case "xls" :
ContentType = "application/vndms-excel" ; break ;
case "gif" :
ContentType = "image/gif" ; break ;
case "jpg" :
ContentType = "image/jpeg" ; break ;
case "jpeg" :
ContentType = "image/jpeg" ; break ;
case "wav" :
ContentType = "audio/wav" ; break ;
case "mp3" :
ContentType = "audio/mpeg3" ; break ;
case "mpg" :
ContentType = "video/mpeg" ; break ;
case "mepg" :
ContentType = "video/mpeg" ; break ;
case "rtf" :
ContentType = "application/rtf" ; break ;
case "html" :
ContentType = "text/html" ; break ;
case "htm" :
ContentType = "text/html" ; break ;
case "txt" :
ContentType = "text/plain" ; break ;
default :
ContentType = "application/octet-stream" ;
break ;
}
return ContentType;
}
*如何获取现有文件的ContentType属性
/// <summary>
/// 获取现有文件的ContentType属性
/// </summary>
/// <param name="filename"></param>
/// <returns></returns>
public string GetFileContentType( string filename)
{
string [] array = filenameSplit( '' );
string result = stringEmpty;
string suffix = "" + array[arrayLength - 1];
MicrosoftWinRegistryKey rg = MicrosoftWinRegistryClassesRootOpenSubKey(suffix);
object obj = rgGetValue( "Content Type" );
result = obj != null ? objToString() : stringEmpty;
rgClose();
return result;
}
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持服务器之家。
原文链接：http://blog.csdn.net/pan_junbiao/article/details/7185382
dy("nrwz");