Question

我在c＃中通过ftp发送一个大文件（3gb），并且在我执行此操作时读取源流中的文件时发生错误：

StreamReader sourceStream = new StreamReader(@"C:\xxx\xxxx\xxx"); 
byte[] fileContents = Encoding.UTF8.GetBytes(sourceStream.ReadToEnd());

错误：

未处理的类型＆＃39; System.OutOfMemoryException＆＃39;发生在mscorlib.dll

整个代码：

// Get the object used to communicate with the server.
FtpWebRequest request = (FtpWebRequest)WebRequest.Create("ftp://xxx.xxx.xxx.xxx/file.iso");
request.Method = WebRequestMethods.Ftp.UploadFile;

// This example assumes the FTP site uses anonymous logon.
request.Credentials = new NetworkCredential("user", "mdp");

// Copy the contents of the file to the request stream.
StreamReader sourceStream = new StreamReader(@"C:\xxx\xxx\xxx\xxxxxxxxx.iso");

byte[] fileContents = Encoding.UTF8.GetBytes(sourceStream.ReadToEnd());
sourceStream.Close();
request.ContentLength = fileContents.Length;

Stream requestStream = request.GetRequestStream();
requestStream.Write(fileContents, 0, fileContents.Length);
requestStream.Close();

FtpWebResponse response = (FtpWebResponse)request.GetResponse();

response.Close();

Answer 1

您无法将3GB文件读入内存缓冲区。你必须做流式传输。使用文件流读入预定义的缓冲区，然后将其写入ftp stream。继续，直到到达文件流的末尾。

// Get the object used to communicate with the server.
FtpWebRequest request = (FtpWebRequest)WebRequest.Create("ftp://xxx.xxx.xxx.xxx/file.iso");
request.Method = WebRequestMethods.Ftp.UploadFile;

// This example assumes the FTP site uses anonymous logon.
request.Credentials = new NetworkCredential("user", "mdp");

// Copy the contents of the file to the request stream.
using (Stream sourceStream = File.OpenRead(@"C:\xxx\xxx\xxx\xxxxxxxxx.iso"))
using(Stream reqStrm = request.GetRequestStream())
{

    byte[] buffer = new byte[1024 * 1024]; //1 MB buffer
    int count = 0;
    do
    {
        count = sourceStream.Read(buffer, 0, buffer.Length);
        if (count > 0)
        {
            reqStrm.Write(buffer, 0, count);
        }
    }
    while (count > 0);
}           
FtpWebResponse response = (FtpWebResponse)request.GetResponse();
response.Close();

通过ftp发送大文件时出错

1 个答案: