用c#怎样从服务器下载文件,并保存为相应的类型

发布网友发布时间：2022-04-28 13:24

共2个回答

热心网友时间：2023-10-10 06:27

C#从服务器下载文件可以使用下面4个方法：TransmitFile、WriteFile、WriteFile和流方式下载文件，并保存为相应类型，方法如下：

1、TransmitFile实现下载

protected void Button1_Click(object sender, EventArgs e)
    {
        /*
        微软为Response对象提供了一个新的方法TransmitFile来解决使用Response.BinaryWrite
        下载超过400mb的文件时导致Aspnet_wp.exe进程回收而无法成功下载的问题。
        代码如下：
        */
        Response.ContentType = "application/x-zip-compressed";
        Response.AddHeader("Content-Disposition", "attachment;filename=z.zip");
        string filename = Server.MapPath("DownLoad/z.zip");
        Response.TransmitFile(filename);
    }

2、WriteFile实现下载

protected void Button2_Click(object sender, EventArgs e)
    {
        /*
        using System.IO;

        */
        string fileName = "asd.txt";//客户端保存的文件名
        string filePath = Server.MapPath("DownLoad/aaa.txt");//路径

        FileInfo fileInfo = new FileInfo(filePath);
        Response.Clear();
        Response.ClearContent();
        Response.ClearHeaders();
        Response.AddHeader("Content-Disposition", "attachment;filename=" + fileName);
        Response.AddHeader("Content-Length", fileInfo.Length.ToString());
        Response.AddHeader("Content-Transfer-Encoding", "binary");
        Response.ContentType = "application/octet-stream";
        Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");
        Response.WriteFile(fileInfo.FullName);
        Response.Flush();
        Response.End();
    }

3、WriteFile分块下载

protected void Button3_Click(object sender, EventArgs e)
    {
        string fileName = "aaa.txt";//客户端保存的文件名
        string filePath = Server.MapPath("DownLoad/aaa.txt");//路径

        System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath);

        if (fileInfo.Exists == true)
        {
            const long ChunkSize = 102400;//100K 每次读取文件，只读取100K，这样可以缓解服务器的压力
            byte[] buffer = new byte[ChunkSize];

            Response.Clear();
            System.IO.FileStream iStream = System.IO.File.OpenRead(filePath);
            long dataLengthToRead = iStream.Length;//获取下载的文件总大小
            Response.ContentType = "application/octet-stream";
            Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName));
            while (dataLengthToRead > 0 && Response.IsClientConnected)
            {
                int lengthRead = iStream.Read(buffer, 0, Convert.ToInt32(ChunkSize));//读取的大小
                Response.OutputStream.Write(buffer, 0, lengthRead);
                Response.Flush();
                dataLengthToRead = dataLengthToRead - lengthRead;
            }
            Response.Close();
        }
    }

4、流方式下载

protected void Button4_Click(object sender, EventArgs e)
    {
        string fileName = "aaa.txt";//客户端保存的文件名
        string filePath = Server.MapPath("DownLoad/aaa.txt");//路径

        //以字符流的形式下载文件
        FileStream fs = new FileStream(filePath, FileMode.Open);
        byte[] bytes = new byte[(int)fs.Length];
        fs.Read(bytes, 0, bytes.Length);
        fs.Close();
        Response.ContentType = "application/octet-stream";
        //通知浏览器下载文件而不是打开
        Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
        Response.BinaryWrite(bytes);
        Response.Flush();
        Response.End();
    }

热心网友时间：2023-10-10 06:28

try
{
string savePath = ""//保存路劲
, downFileUrl = "";//下载文件链接地址
WebClient wcClient = new WebClient();
WebRequest webReq = WebRequest.Create(downFileUrl);
WebResponse webRes = webReq.GetResponse();
int fileLength = webRes.ContentLength;

Stream srm = webRes.GetResponseStream();
StreamReader srmReader = new StreamReader(srm);
byte[] bufferbyte = new byte[fileLength];
int allByte = (int)bufferbyte.Length;
int startByte = 0;
while (fileLength > 0)
{
//Application.DoEvents();
int downByte = srm.Read(bufferbyte, startByte, allByte);
if (downByte == 0) { break; };
startByte += downByte;
allByte -= downByte;
}

if (!File.Exists(savePath))
{
string[] dirArray = savePath.Split('\\');
string temp = string.Empty;
for (int i = 0; i < dirArray.Length - 1; i++)
{
temp += dirArray[i].Trim() + "\\";
if (!Directory.Exists(temp))
Directory.CreateDirectory(temp);
}
}
FileStream fs = new FileStream(savePath, FileMode.OpenOrCreate, FileAccess.Write);
fs.Write(bufferbyte, 0, bufferbyte.Length);
srm.Close();
srmReader.Close();
fs.Close();
}
catch (WebException ex)
{
throw ex;
}

用这段代码试试我自己一直用这个代码下载的貌似我当初测试的时候是用DOC测的

今天测试了下自己的代码可以下DOC 我怀疑你的还是编码问题

热心网友时间：2023-10-10 06:27

C#从服务器下载文件可以使用下面4个方法：TransmitFile、WriteFile、WriteFile和流方式下载文件，并保存为相应类型，方法如下：

1、TransmitFile实现下载

2、WriteFile实现下载

3、WriteFile分块下载

4、流方式下载

热心网友时间：2023-10-10 06:28

热心网友时间：2023-10-10 06:27

C#从服务器下载文件可以使用下面4个方法：TransmitFile、WriteFile、WriteFile和流方式下载文件，并保存为相应类型，方法如下：

1、TransmitFile实现下载

2、WriteFile实现下载

3、WriteFile分块下载

4、流方式下载

热心网友时间：2023-10-10 06:28