我正在编写一个WPF应用程序,该应用程序可以将文件上传到社交网络之一。上传本身正常运行,但我想提供一些指示来显示上传进度。
我尝试了很多方法来实现这一点:
1)HttpWebRequest.GetStream方法:
using (
var FS = File.Open(
localFilePath, FileMode.Open, FileAccess.Read, FileShare.Read))
{
long len = FS.Length;
HttpWebRequest request = (HttpWebRequest) WebRequest.Create(url);
request.Method = "POST";
request.ProtocolVersion = HttpVersion.Version11;
request.ContentType = "multipart/form-data; boundary=--AaB03x";
//predata and postdata is two byte[] arrays, that contains
//strings for MIME file upload (defined above and is not important)
request.ContentLength = predata.Length + FS.Length + postdata.Length;
request.AllowWriteStreamBuffering = false;
using (var reqStream = request.GetRequestStream())
{
reqStream.Write(predata, 0, predata.Length);
int bytesRead = 0;
int totalRead = 0;
do
{
bytesRead = FS.Read(fileData, 0, MaxContentSize);
totalRead += bytesRead;
reqStream.Write(fileData, 0, bytesRead);
reqStream.Flush(); //trying with and without this
//this part will show progress in percents
sop.prct = (int) ((100*totalRead)/len);
} while (bytesRead > 0);
reqStream.Write(postdata, 0, postdata.Length);
}
HttpWebResponse responce = (HttpWebResponse) request.GetResponse();
using (var respStream = responce.GetResponseStream())
{
//do things
}
}
2) WebClient方式(更短):
void UploadFile (url, localFilePath)
{
...
WebClient client = new WebClient();
client.UploadProgressChanged += new UploadProgressChangedEventHandler(UploadPartDone);
client.UploadFileCompleted += new UploadFileCompletedEventHandler(UploadComplete);
client.UploadFileAsync(new Uri(url), localFilePath);
done.WaitOne();
//do things with responce, received from UploadComplete
JavaScriptSerializer jssSer = new JavaScriptSerializer();
return jssSer.Deserialize<UniversalJSONAnswer>(utf8.GetString(UploadFileResponce));
//so on...
...
}
void UploadComplete(object sender, UploadFileCompletedEventArgs e)
{
UploadFileResponce=e.Result;
done.Set();
}
void UploadPartDone(object sender, UploadProgressChangedEventArgs e)
{
//this part expected to show progress
sop.prct=(int)(100*e.BytesSent/e.TotalBytesToSend);
}
3) 即使是TcpClient方法:
using (
var FS = File.Open(
localFilePath, FileMode.Open, FileAccess.Read, FileShare.Read))
{
long len = FS.Length;
long totalRead = 0;
using (var client = new TcpClient(urli.Host, urli.Port))
{
using (var clearstream = client.GetStream())
{
using (var writer = new StreamWriter(clearstream))
using (var reader = new StreamReader(clearstream))
{
//set progress to 0
sop.prct = 0;
// Send request headers
writer.WriteLine("POST " + urli.AbsoluteUri + " HTTP/1.1");
writer.WriteLine("Content-Type: multipart/form-data; boundary=--AaB03x");
writer.WriteLine("Host: " + urli.Host);
writer.WriteLine("Content-Length: " + (predata.Length + len + postdata.Length).ToString());
writer.WriteLine();
//some data for MIME
writer.Write(utf8.GetString(predata));
writer.Flush();
int bytesRead;
do
{
bytesRead = FS.Read(fileData, 0, MaxContentSize);
totalRead += bytesRead;
writer.BaseStream.Write(fileData, 0, bytesRead);
writer.BaseStream.Flush();
sop.prct = (int) ((100*totalRead)/len);
} while (bytesRead > 0)
writer.Write(utf8.GetString(postdata));
writer.Flush();
//read line of response and do other thigs...
respStr = reader.ReadLine();
...
}
}
}
}
在所有情况下,文件都成功地发送到了服务器。 但是进度总是像这样:几秒钟内从0跑到100,然后等待文件实际上传(大约5分钟——文件大小为400MB)。
因此我认为文件的数据在某个地方被缓冲了,我正在追踪的不是上传,而是缓冲数据。然后必须等待它上传完毕。
我的问题是:
1) 是否有任何方法可以跟踪实际上传的数据?即 Stream.Write() 或 Flush() 方法(据我所读,对于 NetworkStream 不起作用)没有接收到来自服务器确认 TCP 数据包已接收之前就返回。
2) 或者我可以拒绝缓冲(HttpWebRequest 的 AllowWriteStreamBUffering 不起作用)?
3) 进一步"向下"尝试使用套接字是否有意义?
更新: 为避免在 UI 上显示进度时产生任何疑惑,我重写了代码以记录文件。 因此,以下是代码:
using (var LogStream=File.Open("C:\\123.txt",FileMode.Create,FileAccess.Write,FileShare.Read))
using (var LogWriter=new StreamWriter(LogStream))
using (var FS = File.Open(localFilePath, FileMode.Open, FileAccess.Read, FileShare.Read))
{
long len = FS.Length;
HttpWebRequest request = (HttpWebRequest) WebRequest.Create(url);
request.Timeout = 7200000; //2 hour timeout
request.Method = "POST";
request.ProtocolVersion = HttpVersion.Version11;
request.ContentType = "multipart/form-data; boundary=--AaB03x";
//predata and postdata is two byte[] arrays, that contains
//strings for MIME file upload (defined above and is not important)
request.ContentLength = predata.Length + FS.Length + postdata.Length;
request.AllowWriteStreamBuffering = false;
LogWriter.WriteLine(DateTime.Now.ToString("o") + " Start write into request stream. ");
using (var reqStream = request.GetRequestStream())
{
reqStream.Write(predata, 0, predata.Length);
int bytesRead = 0;
int totalRead = 0;
do
{
bytesRead = FS.Read(fileData, 0, MaxContentSize);
totalRead += bytesRead;
reqStream.Write(fileData, 0, bytesRead);
reqStream.Flush(); //trying with and without this
//sop.prct = (int) ((100*totalRead)/len); //this part will show progress in percents
LogWriter.WriteLine(DateTime.Now.ToString("o") + " totalRead= " + totalRead.ToString() + " / " + len.ToString());
} while (bytesRead > 0);
reqStream.Write(postdata, 0, postdata.Length);
}
LogWriter.WriteLine(DateTime.Now.ToString("o") + " All sent!!! Waiting for responce... ");
LogWriter.Flush();
HttpWebResponse responce = (HttpWebResponse) request.GetResponse();
LogWriter.WriteLine(DateTime.Now.ToString("o") + " Responce received! ");
using (var respStream = responce.GetResponseStream())
{
if (respStream == null) return null;
using (var streamReader = new StreamReader(respStream))
{
string resp = streamReader.ReadToEnd();
JavaScriptSerializer jssSer = new JavaScriptSerializer();
return jssSer.Deserialize<UniversalJSONAnswer>(resp);
}
}
}
这里是结果(我删去了中间部分):
2011-11-19T22:00:54.5964408+04:00 Start write into request stream.
2011-11-19T22:00:54.6404433+04:00 totalRead= 1048576 / 410746880
2011-11-19T22:00:54.6424434+04:00 totalRead= 2097152 / 410746880
2011-11-19T22:00:54.6434435+04:00 totalRead= 3145728 / 410746880
2011-11-19T22:00:54.6454436+04:00 totalRead= 4194304 / 410746880
2011-11-19T22:00:54.6464437+04:00 totalRead= 5242880 / 410746880
2011-11-19T22:00:54.6494438+04:00 totalRead= 6291456 / 410746880
.......
2011-11-19T22:00:55.3434835+04:00 totalRead= 408944640 / 410746880
2011-11-19T22:00:55.3434835+04:00 totalRead= 409993216 / 410746880
2011-11-19T22:00:55.3464837+04:00 totalRead= 410746880 / 410746880
2011-11-19T22:00:55.3464837+04:00 totalRead= 410746880 / 410746880
2011-11-19T22:00:55.3464837+04:00 All sent!!! Waiting for responce...
2011-11-19T22:07:23.0616597+04:00 Responce received!
正如您所看到的,程序认为它在大约2秒钟内上传了约400MB的文件。但是在7分钟后,文件实际上才上传完成,并且我收到了响应。
再次更新:
似乎这种情况发生在Windows 7下(不确定是x64还是x86)。 当我在XP下运行代码时,一切都完美地工作,进度条也显示得非常正确。