Uploadfile with Post Values by Webclient

UploadFile with POST values by WebClient

There's nothing built-in that allows you to do that. I have blogged about an extension that you could use. Here are the relevant classes:

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();
    }
}

and now you could use it in your application:

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);
}

Now in your PHP script you could use the $_POST["client"], $_POST["name"] and $_FILES["file"].

WebClient Upload file with variables posted

you can add a header like this

webClient.Headers.Add("OurSecurityHeader", "encryptedvalue");

On the php side, you can use this to read headers:

How do I read any request header in PHP

File upload via multipart-form-data using WebClient in C#

If you need both files and objects in the payload you can use a multipart form like this:

Form

<form id="createForm" method="post" enctype="multipart/form-data" action="http://localhost:5000/api/send">
<input type="text" name="Field1"  id="field1" />
<input type="text" name="Field2"  id="field2" />
<input type="file" id="bulk" name="Bulk" required />
</form>

POCO

class MyClass
{
  public string Field1{get;set;}
  public string Field2{get;set;}
}

Controller
In the controller you can access the files using Request.Form.Files which gives you a collection with all your uploaded files.Then you can read your file(s) using a StreamReader like i do below:

[HttpPost]
[Route("api/send")]
[DisableRequestSizeLimit] 
public async Task<long> CreateAsync(MyClass obj) {
{
  var file=this.Request.Form.Files[0];  //there's only one in our form
  using(StreamReader reader=new StreamReader(file))
  {
    var data=await reader.ReadToEndAsync();
    Console.WriteLine("File Content:"+data);
    Console.WriteLine("{ Field1 :"+obj.Field1.ToString()+",Field2:"+obj.Field2.ToString()+"}");
  }

}

Caution
Take care when dealing with multipart since you will also need to specify the maximum size of a segment.
That is done in the Startup:

public void ConfigureServices(IServiceCollection services) {
    services.Configure<FormOptions>(options => {
                    options.ValueCountLimit = 200;
                    options.ValueLengthLimit = int.MaxValue;
                    options.MultipartBodyLengthLimit = long.MaxValue;
                });
 }

or like i did it directly in the Controller-s method , by decorating it with [DisableRequestSizeLimit] attribute.

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