我想使用 WebClient 类将文件上传到主机。我还想传递一些值，这些值应该显示在服务器部分（PHP）的 $_POST 数组中。我想通过一个连接来完成
我使用了下面的代码
using (WebClient wc = new WebClient())
{
wc.Encoding = Encoding.UTF8;
NameValueCollection values = new NameValueCollection();
values.Add("client", "VIP");
values.Add("name", "John Doe");
wc.QueryString = values; // this displayes in $_GET
byte[] ans= wc.UploadFile(address, dumpPath);
}
如果我使用了 QueryString 属性，则 $_GET 数组中显示的值。但我想通过 post 方法发送它
没有内置的东西可以让你这样做。我在博客上写了一个你可以使用的扩展。以下是相关类：
public class UploadFile
{
public UploadFile()
{
ContentType = "application/octet-stream";
}
public string Name { get; set; }
public string Filename { get; set; }
public string ContentType { get; set; }
public Stream Stream { get; set; }
}
public byte[] UploadFiles(string address, IEnumerable<UploadFile> files, NameValueCollection values)
{
var request = WebRequest.Create(address);
request.Method = "POST";
var boundary = "---------------------------" + DateTime.Now.Ticks.ToString("x", NumberFormatInfo.InvariantInfo);
request.ContentType = "multipart/form-data; boundary=" + boundary;
boundary = "--" + boundary;
using (var requestStream = request.GetRequestStream())
{
// Write the values
foreach (string name in values.Keys)
{
var buffer = Encoding.ASCII.GetBytes(boundary + Environment.NewLine);
requestStream.Write(buffer, 0, buffer.Length);
buffer = Encoding.ASCII.GetBytes(string.Format("Content-Disposition: form-data; name=\"{0}\"{1}{1}", name, Environment.NewLine));
requestStream.Write(buffer, 0, buffer.Length);
buffer = Encoding.UTF8.GetBytes(values[name] + Environment.NewLine);
requestStream.Write(buffer, 0, buffer.Length);
}
// Write the files
foreach (var file in files)
{
var buffer = Encoding.ASCII.GetBytes(boundary + Environment.NewLine);
requestStream.Write(buffer, 0, buffer.Length);
buffer = Encoding.UTF8.GetBytes(string.Format("Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"{2}", file.Name, file.Filename, Environment.NewLine));
requestStream.Write(buffer, 0, buffer.Length);
buffer = Encoding.ASCII.GetBytes(string.Format("Content-Type: {0}{1}{1}", file.ContentType, Environment.NewLine));
requestStream.Write(buffer, 0, buffer.Length);
file.Stream.CopyTo(requestStream);
buffer = Encoding.ASCII.GetBytes(Environment.NewLine);
requestStream.Write(buffer, 0, buffer.Length);
}
var boundaryBuffer = Encoding.ASCII.GetBytes(boundary + "--");
requestStream.Write(boundaryBuffer, 0, boundaryBuffer.Length);
}
using (var response = request.GetResponse())
using (var responseStream = response.GetResponseStream())
using (var stream = new MemoryStream())
{
responseStream.CopyTo(stream);
return stream.ToArray();
}
}
现在您可以在您的应用程序中使用它：
using (var stream = File.Open(dumpPath, FileMode.Open))
{
var files = new[]
{
new UploadFile
{
Name = "file",
Filename = Path.GetFileName(dumpPath),
ContentType = "text/plain",
Stream = stream
}
};
var values = new NameValueCollection
{
{ "client", "VIP" },
{ "name", "John Doe" },
};
byte[] result = UploadFiles(address, files, values);
}
现在在您的 PHP 脚本中，您可以使用$_POST["client"],$_POST["name"]和$_FILES["file"].
如果有人想在带有进度报告的异步模式中使用@darin-dimitrov 的解决方案，那就是要走的路（对于.NET 4.0）：
public void UploadFileAsync(NameValueCollection values, Stream fileStream)
{
//to fire events on the calling thread
_asyncOperation = AsyncOperationManager.CreateOperation(null);
var ms = new MemoryStream();
//make a copy of the input stream in case sb uses disposable stream
fileStream.CopyTo(ms);
//you cannot set stream position often enough to zero
ms.Position = 0;
Task.Factory.StartNew(() =>
{
try
{
const string contentType = "application/octet-stream";
var request = WebRequest.Create(_url);
request.Method = "POST";
var boundary = "---------------------------" + DateTime.Now.Ticks.ToString("x", NumberFormatInfo.InvariantInfo);
request.ContentType = "multipart/form-data; boundary=" + boundary;
boundary = "--" + boundary;
var dataStream = new MemoryStream();
byte[] buffer;
// Write the values
foreach (string name in values.Keys)
{
buffer = Encoding.ASCII.GetBytes(boundary + Environment.NewLine);
dataStream.Write(buffer, 0, buffer.Length);
buffer = Encoding.ASCII.GetBytes(string.Format("Content-Disposition: form-data; name=\"{0}\"{1}{1}", name, Environment.NewLine));
dataStream.Write(buffer, 0, buffer.Length);
buffer = Encoding.UTF8.GetBytes(values[name] + Environment.NewLine);
dataStream.Write(buffer, 0, buffer.Length);
}
// Write the file
buffer = Encoding.ASCII.GetBytes(boundary + Environment.NewLine);
dataStream.Write(buffer, 0, buffer.Length);
buffer = Encoding.UTF8.GetBytes($"Content-Disposition: form-data; name=\"file\"; filename=\"file\"{Environment.NewLine}");
dataStream.Write(buffer, 0, buffer.Length);
buffer = Encoding.ASCII.GetBytes(string.Format("Content-Type: {0}{1}{1}", contentType, Environment.NewLine));
dataStream.Write(buffer, 0, buffer.Length);
ms.CopyTo(dataStream);
buffer = Encoding.ASCII.GetBytes(Environment.NewLine);
dataStream.Write(buffer, 0, buffer.Length);
buffer = Encoding.ASCII.GetBytes(boundary + "--");
dataStream.Write(buffer, 0, buffer.Length);
dataStream.Position = 0;
//IMPORTANT: set content length to directly write to network socket
request.ContentLength = dataStream.Length;
var requestStream = request.GetRequestStream();
//Write data in chunks and report progress
var size = dataStream.Length;
const int chunkSize = 64 * 1024;
buffer = new byte[chunkSize];
long bytesSent = 0;
int readBytes;
while ((readBytes = dataStream.Read(buffer, 0, buffer.Length)) > 0)
{
requestStream.Write(buffer, 0, readBytes);
bytesSent += readBytes;
var status = "Uploading... " + bytesSent / 1024 + "KB of " + size / 1024 + "KB";
var percentage = Tools.Clamp(Convert.ToInt32(100 * bytesSent / size), 0, 100);
OnFileUploaderProgressChanged(new FileUploaderProgessChangedEventArgs(status, percentage));
}
//get response
using (var response = request.GetResponse())
using (var responseStream = response.GetResponseStream())
using (var stream = new MemoryStream())
{
// ReSharper disable once PossibleNullReferenceException - exception would get catched anyway
responseStream.CopyTo(stream);
var result = Encoding.Default.GetString(stream.ToArray());
OnFileUploaderCompleted(result == string.Empty
? new FileUploaderCompletedEventArgs(FileUploaderCompletedResult.Failed)
: new FileUploaderCompletedEventArgs(FileUploaderCompletedResult.Ok));
}
}
catch (Exception)
{
OnFileUploaderCompleted(new FileUploaderCompletedEventArgs(FileUploaderCompletedResult.Failed));
}
}, CancellationToken.None, TaskCreationOptions.LongRunning, TaskScheduler.Default);
}