Question

我在ftp服务器上有一些zip文件，我想通过代码下载，但每次下载并尝试打开它们都会损坏。

    FtpClient conn = new FtpClient();

    conn.Host = ftpFtpServerAddress;
    conn.Credentials = new NetworkCredential(ftpSrcUsername, ftpSrcPwd);
    var files = conn.GetListing(ftpSrcFolder, FtpListOption.Modify | FtpListOption.Size);

    foreach (var file in files)
    {
        conn.BeginOpenRead(file.FullName,
            new AsyncCallback(BeginOpenReadCallback), new AsyncArguments()
            {
                Client = conn,
                FileName = file.Name
            });
    }

    private void BeginOpenReadCallback(IAsyncResult ar)
    {         
        AsyncArguments args = (AsyncArguments)ar.AsyncState;
        FtpClient conn = args.Client;

        Stream istream = conn.EndOpenRead(ar);
        using (System.IO.FileStream fs = System.IO.File.Create(@"C:\temp\" + args.FileName))
        {
            byte[] bytes = new byte[istream.Length + 10];
            int numBytesToRead = (int)istream.Length;
            fs.Write(bytes, 0, numBytesToRead);
        }                    
    }

Answer 1

现在使用stream.Read。虽然这种方法对于小文件是可以的，但是你不应该将它用于非常大的文件，因为它会非常快地填满你的内存，并且大于2 gb的文件的字节大小不能存储为int32。

    private void BeginOpenReadCallback(IAsyncResult ar)
    {
        AsyncObject args = (AsyncObject)ar.AsyncState;
        FtpClient conn = args.conn;

        Stream istream = conn.EndOpenRead(ar);
        using (System.IO.FileStream fs = System.IO.File.Create(@"C:\temp\" + args.filename))
        {
            byte[] bytes = new byte[istream.Length];
            int bytesread = istream.Read(bytes, 0, bytes.Length);
            fs.Write(bytes, 0, bytesread);
        }
    }

如何通过代码下载.zip文件？

1 个答案: