Develop Reference

Google Document AI c# mime Unsupported input file format

I am trying to upload a pdf for processing to google's Document AI service. Using google's using Google.Cloud.DocumentAI.V1 for "C#". Looked at the github and docs, not much info. PDF is on the local drive. I converted the pdf to a byte array then converted that to a Bystring. Then set the request mime to "application/pdf" but it return was an error of:
Status(StatusCode="InvalidArgument", Detail="Unsupported input file format.", DebugException="Grpc.Core.Internal.CoreErrorDetailException: {"created":"#1627582435.256000000","description":"Error received from peer ipv4:142.250.72.170:443","file":"......\src\core\lib\surface\call.cc","file_line":1067,"grpc_message":"Unsupported input file format.","grpc_status":3}")
Code:
try
{
//Generate a document
string pdfFilePath = "C:\\Users\\maponte\\Documents\\Projects\\SettonProjects\\OCRSTUFF\\DOC071621-0016.pdf";
var bytes = Encoding.UTF8.GetBytes(pdfFilePath);
ByteString content = ByteString.CopyFrom(bytes);
// Create client
DocumentProcessorServiceClient documentProcessorServiceClient = await DocumentProcessorServiceClient.CreateAsync();
// Initialize request argument(s)
ProcessRequest request = new ProcessRequest
{
ProcessorName = ProcessorName.FromProjectLocationProcessor("*****", "mycountry", "***"),
SkipHumanReview = false,
InlineDocument = new Document(),
RawDocument = new RawDocument(),
};
request.RawDocument.MimeType = "application/pdf";
request.RawDocument.Content = content;
// Make the request
ProcessResponse response = await documentProcessorServiceClient.ProcessDocumentAsync(request);
Document docResponse = response.Document;
Console.WriteLine(docResponse.Text);
}
catch(Exception ex)
{
Console.WriteLine(ex.Message);
}

This is the problem (or at least one problem) - you aren't actually loading the file:
string pdfFilePath = "C:\\Users\\maponte\\Documents\\Projects\\SettonProjects\\OCRSTUFF\\DOC071621-0016.pdf";
var bytes = Encoding.UTF8.GetBytes(pdfFilePath);
ByteString content = ByteString.CopyFrom(bytes);
You instead want:
string pdfFilePath = "path-as-before";
var bytes = File.ReadAllBytes(pdfFilePath);
ByteString content = ByteString.CopyFrom(bytes);
I'd also note, however, that InlineDocument and RawDocument are alternatives to each other - specifying either of them removes the other. Your request creation would be better written as:
ProcessRequest request = new ProcessRequest
{
ProcessorName = ProcessorName.FromProjectLocationProcessor("*****", "mycountry", "***"),
SkipHumanReview = false,
RawDocument = new RawDocument
{
MimeType = "application/pdf",
Content = content
}
};

C# Web API Sending Body Data in HTTP Post REST Client

I need to send this HTTP Post Request:
POST https://webapi.com/baseurl/login
Content-Type: application/json
{"Password":"password",
"AppVersion":"1",
"AppComments":"",
"UserName":"username",
"AppKey":"dakey"
}
It works great in RestClient and PostMan just like above.
I need to have this pro-grammatically and am not sure if to use
WebClient, HTTPRequest or WebRequest to accomplish this.
The problem is how to format the Body Content and send it above with the request.
Here is where I am with example code for WebClient...
private static void Main(string[] args)
{
RunPostAsync();
}
static HttpClient client = new HttpClient();
private static void RunPostAsync(){
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(
new MediaTypeWithQualityHeaderValue("application/json"));
Inputs inputs = new Inputs();
inputs.Password = "pw";
inputs.AppVersion = "apv";
inputs.AppComments = "apc";
inputs.UserName = "user";
inputs.AppKey = "apk";
var res = client.PostAsync("https://baseuriplus", new StringContent(JsonConvert.SerializeObject(inputs)));
try
{
res.Result.EnsureSuccessStatusCode();
Console.WriteLine("Response " + res.Result.Content.ReadAsStringAsync().Result + Environment.NewLine);
}
catch (Exception ex)
{
Console.WriteLine("Error " + res + " Error " +
ex.ToString());
}
Console.WriteLine("Response: {0}", result);
}
public class Inputs
{
public string Password;
public string AppVersion;
public string AppComments;
public string UserName;
public string AppKey;
}
This DOES NOW WORK and responses with a (200) OK Server and Response

Why are you generating you own json?
Use JSONConvert from JsonNewtonsoft.
Your json object string values need " " quotes and ,
I'd use http client for Posting, not webclient.
using (var client = new HttpClient())
{
var res = client.PostAsync("YOUR URL",
new StringContent(JsonConvert.SerializeObject(
new { OBJECT DEF HERE },
Encoding.UTF8, "application/json")
);
try
{
res.Result.EnsureSuccessStatusCode();
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}

You are not properly serializing your values to JSON before sending. Instead of trying to build the string yourself, you should use a library like JSON.Net.
You could get the correct string doing something like this:
var message = JsonConvert.SerializeObject(new {Password = pw, AppVersion = apv, AppComments = acm, UserName = user, AppKey = apk});
Console.WriteLine(message); //Output: {"Password":"password","AppVersion":"10","AppComments":"","UserName":"username","AppKey":"dakey"}

var client = new RestClient("Your URL");
var request = new RestRequest(Method.POST);
request.AddHeader("Content-Type", "application/json");
request.AddHeader("apk-key", apk);
//Serialize to JSON body.
JObject jObjectbody = new JObject();
jObjectbody.Add("employeeName", data.name);
jObjectbody.Add("designation", data.designation);
request.AddParameter("application/json", jObjectbody, ParameterType.RequestBody);
try
{
var clientValue= client.Execute<Response>(request);
return RequestResponse<Response>.Create(ResponseCode.OK, "", clientValue.Data);
}
catch (Exception exception)
{
throw exception;
}

I made a tools to do it quick and easy:
Install-Package AdvancedRestHandler
or
dotnet add package AdvancedRestHandler
AdvancedRestHandler arh = new AdvancedRestHandler("https://webapi.com/baseurl");
var result = await arh.PostDataAsync<MyLoginResponse, MyLoginRequest>("/login", new MyLoginRequest{
Password = "password",
AppVersion = "1",
AppComments = "",
UserName = "username",
AppKey = "dakey"
});
public class MyLoginRequest{
public string Password{get;set;}
public string AppVersion{get;set;}
public string AppComments{get;set;}
public string UserName{get;set;}
public string AppKey{get;set;}
}
public class MyLoginResponse {
public string Token{get;set;}
}
Extra:
One other thing you can do is to use ArhResponse:
Either this way, in the class definition:
public class MyLoginResponse: ArhResponse
{
...
}
Or this way, in the API call:
var result = await arh.PostDataAsync<ArhResponse<MyLoginResponse>, MyLoginRequest> (...)
and instead of try or cache, check your API call state using simple if statements:
// check service response status:
if(result.ResponseStatusCode == HttpStatusCode.OK) { /* api receive success response data */ }
// check Exceptions that may occur due to implementation change, or model errors
if(result.Exception!=null) { /* mostly serializer failed due to model mismatch */ }
// have a copy of request and response, in case the service provider need your request response and they think you are hand writing the service and believe you are wrong
_logger.Warning(result.ResponseText);
_logger.Warning(result.RequestText);
// Get deserialized verion of, one of the fallback models, in case the provider uses more than one type of data in same property of the model
var fallbackData = (MyFallbackResponse)result.FallbackModel;
Header Possible Issue
There are cases that the Server does not accept C# request due to the header that the HttpClient generates.
It is because HttpClient by default uses the value of application/json; charset=utf-8 for Content-Type...
For sending only application/json part as Content-Type and ignore the ; charset=utf-8 part, you can do as following:
For HttpClient you can fix it by looking into this thread: How do you set the Content-Type header for an HttpClient request?
As for (AdvancedRestHandler) ARH, I fixed it due to integration with some company, but I don't remember fully... I did it, either through options like of requests or through resetting the header value.

we will use HttpPost with HttpClient PostAsync for the issue.
using System.Net.Http;
static async Task<string> PostURI(Uri u, HttpContent c)
{
var response = string.Empty;
using (var client = new HttpClient())
{
HttpResponseMessage result = await client.PostAsync(u, c);
if (result.IsSuccessStatusCode)
{
response = result.StatusCode.ToString();
}
}
return response;
}
We will call it by creating a string that we will use to post:
Uri u = new Uri("http://localhost:31404/Api/Customers");
var payload = "{\"CustomerId\": 5,\"CustomerName\": \"Pepsi\"}";
HttpContent c = new StringContent(payload, Encoding.UTF8, "application/json");
var t = Task.Run(() => PostURI(u, c));
t.Wait();
Console.WriteLine(t.Result);
Console.ReadLine();

How to implement apple token based push notifications (using p8 file) in C#?

For an app with some kind of chat based features I want to add push notification support for receiving new messages.
What I want to do is use the new token based authentication (.p8 file) from Apple, but I can't find much info about the server part.
I came across the following post:
How to use APNs Auth Key (.p8 file) in C#?
However the answer was not satisfying as there was not much detail about how to:
establish a connection with APNs
use the p8 file (except for some kind of encoding)
send data to the Apple Push Notification Service

You can't really do this on raw .NET Framework at the moment. The new JWT-based APNS server uses HTTP/2 only, which .NET Framework does not yet support.
.NET Core's version of System.Net.Http, however, does, provided you meet the following prerequisites:
On Windows, you must be running Windows 10 Anniversary Edition (v1607) or higher, or the equivalent build of Windows Server 2016 (I think).
On Linux, you must have a version of libcurl that supports HTTP/2.
On macOS, you have to compile libcurl with support for HTTP/2, then use the DYLD_INSERT_LIBRARIES environment variable in order to load your custom build of libcurl.
You should be able to use .NET Core's version of System.Net.Http in the .NET Framework if you really want.
I have no idea what happens on Mono, Xamarin or UWP.
There are then three things you have to do:
Parse the private key that you have been given. This is currently an ECDSA key, and you can load this into a System.Security.Cryptography.ECDsa object.
On Windows, you can use the CNG APIs. After parsing the base64-encoded DER part of the key file, you can then create a key with new ECDsaCng(CngKey.Import(data, CngKeyBlobFormat.Pkcs8PrivateBlob)).
On macOS or Linux there is no supported API and you have to parse the DER structure yourself, or use a third-party library.
Create a JSON Web Token / Bearer Token. If you use the System.IdentityModel.Tokens.Jwt package from NuGet, this is fairly simple. You will need the Key ID and Team ID from Apple.
public static string CreateToken(ECDsa key, string keyID, string teamID)
{
var securityKey = new ECDsaSecurityKey(key) { KeyId = keyID };
var credentials = new SigningCredentials(securityKey, SecurityAlgorithms.EcdsaSha256);
var descriptor = new SecurityTokenDescriptor
{
IssuedAt = DateTime.Now,
Issuer = teamID,
SigningCredentials = credentials
};
var handler = new JwtSecurityTokenHandler();
var encodedToken = handler.CreateEncodedJwt(descriptor);
return encodedToken;
}
Send an HTTP/2 request. This is as normal, but you need to do two extra things:
Set yourRequestMessage.Version to new Version(2, 0) in order to make the request using HTTP/2.
Set yourRequestMessage.Headers.Authorization to new AuthenticationHeaderValue("bearer", token) in order to provide the bearer authentication token / JWT with your request.
Then just put your JSON into the HTTP request and POST it to the correct URL.

Because Token (.p8) APNs only works in HTTP/2, thus most of the solutions only work in .net Core. Since my project is using .net Framework, some tweak is needed. If you're using .net Framework like me, please read on.
I search here and there and encountered several issues, which I managed to fix and pieced them together.
Below is the APNs class that actually works. I created a new class library for it, and placed the .P8 files within the AuthKeys folder of the class library. REMEMBER to right click on the .P8 files and set it to "Always Copy". Refer Get relative file path in a class library project that is being referenced by a web project.
After that, to get the location of the P8 files, please use AppDomain.CurrentDomain.RelativeSearchPath for web project or AppDomain.CurrentDomain.BaseDirectory for win application. Refer Why AppDomain.CurrentDomain.BaseDirectory not contains "bin" in asp.net app?
To get the token from the P8, you'll need to use the BouncyCastle class, please download it from Nuget.
using Jose;
using Newtonsoft.Json;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.OpenSsl;
using Security.Cryptography;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;
namespace PushLibrary
{
public class ApplePushNotificationPush
{
//private const string WEB_ADDRESS = "https://api.sandbox.push.apple.com:443/3/device/{0}";
private const string WEB_ADDRESS = "https://api.push.apple.com:443/3/device/{0}";
private string P8_PATH = AppDomain.CurrentDomain.RelativeSearchPath + #"\AuthKeys\APNs_AuthKey.p8";
public ApplePushNotificationPush()
{
}
public async Task<bool> SendNotification(string deviceToken, string title, string content, int badge = 0, List<Tuple<string, string>> parameters = null)
{
bool success = true;
try
{
string data = System.IO.File.ReadAllText(P8_PATH);
List<string> list = data.Split('\n').ToList();
parameters = parameters ?? new List<Tuple<string, string>>();
string prk = list.Where((s, i) => i != 0 && i != list.Count - 1).Aggregate((agg, s) => agg + s);
ECDsaCng key = new ECDsaCng(CngKey.Import(Convert.FromBase64String(prk), CngKeyBlobFormat.Pkcs8PrivateBlob));
string token = GetProviderToken();
string url = string.Format(WEB_ADDRESS, deviceToken);
HttpRequestMessage httpRequestMessage = new HttpRequestMessage(HttpMethod.Post, url);
httpRequestMessage.Headers.Authorization = new AuthenticationHeaderValue("Bearer", token);
httpRequestMessage.Headers.TryAddWithoutValidation("apns-push-type", "alert"); // or background
httpRequestMessage.Headers.TryAddWithoutValidation("apns-id", Guid.NewGuid().ToString("D"));
//Expiry
//
httpRequestMessage.Headers.TryAddWithoutValidation("apns-expiration", Convert.ToString(0));
//Send imediately
httpRequestMessage.Headers.TryAddWithoutValidation("apns-priority", Convert.ToString(10));
//App Bundle
httpRequestMessage.Headers.TryAddWithoutValidation("apns-topic", "com.xxx.yyy");
//Category
httpRequestMessage.Headers.TryAddWithoutValidation("apns-collapse-id", "test");
//
var body = JsonConvert.SerializeObject(new
{
aps = new
{
alert = new
{
title = title,
body = content,
time = DateTime.Now.ToString()
},
badge = 1,
sound = "default"
},
acme2 = new string[] { "bang", "whiz" }
});
httpRequestMessage.Version = new Version(2, 0);
using (var stringContent = new StringContent(body, Encoding.UTF8, "application/json"))
{
//Set Body
httpRequestMessage.Content = stringContent;
Http2Handler.Http2CustomHandler handler = new Http2Handler.Http2CustomHandler();
handler.SslProtocols = System.Security.Authentication.SslProtocols.Tls12 | System.Security.Authentication.SslProtocols.Tls11 | System.Security.Authentication.SslProtocols.Tls;
//handler.ServerCertificateCustomValidationCallback = (message, cert, chain, errors) => true;
//Continue
using (HttpClient client = new HttpClient(handler))
{
HttpResponseMessage resp = await client.SendAsync(httpRequestMessage).ContinueWith(responseTask =>
{
return responseTask.Result;
});
if (resp != null)
{
string apnsResponseString = await resp.Content.ReadAsStringAsync();
handler.Dispose();
}
handler.Dispose();
}
}
}
catch (Exception ex)
{
success = false;
}
return success;
}
private string GetProviderToken()
{
double epochNow = (int)DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1)).TotalSeconds;
Dictionary<string, object> payload = new Dictionary<string, object>()
{
{ "iss", "YOUR APPLE TEAM ID" },
{ "iat", epochNow }
};
var extraHeaders = new Dictionary<string, object>()
{
{ "kid", "YOUR AUTH KEY ID" },
{ "alg", "ES256" }
};
CngKey privateKey = GetPrivateKey();
return JWT.Encode(payload, privateKey, JwsAlgorithm.ES256, extraHeaders);
}
private CngKey GetPrivateKey()
{
using (var reader = File.OpenText(P8_PATH))
{
ECPrivateKeyParameters ecPrivateKeyParameters = (ECPrivateKeyParameters)new PemReader(reader).ReadObject();
var x = ecPrivateKeyParameters.Parameters.G.AffineXCoord.GetEncoded();
var y = ecPrivateKeyParameters.Parameters.G.AffineYCoord.GetEncoded();
var d = ecPrivateKeyParameters.D.ToByteArrayUnsigned();
return EccKey.New(x, y, d);
}
}
}
}
Secondly, if you noticed, I am using the custom WinHTTPHandler to make the code to support HTTP/2 based on How to make the .net HttpClient use http 2.0?. I am creating this using another class library, remember to download WinHTTPHandler from Nuget.
public class Http2CustomHandler : WinHttpHandler
{
protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, System.Threading.CancellationToken cancellationToken)
{
request.Version = new Version("2.0");
return base.SendAsync(request, cancellationToken);
}
}
After that, just call the "SendNotification" on the ApplePushNotificationPush class and you should get the message on your iPhone.

private string GetToken()
{
var dsa = GetECDsa();
return CreateJwt(dsa, "keyId", "teamId");
}
private ECDsa GetECDsa()
{
using (TextReader reader = System.IO.File.OpenText("AuthKey_xxxxxxx.p8"))
{
var ecPrivateKeyParameters =
(ECPrivateKeyParameters)new Org.BouncyCastle.OpenSsl.PemReader(reader).ReadObject();
var q = ecPrivateKeyParameters.Parameters.G.Multiply(ecPrivateKeyParameters.D).Normalize();
var qx = q.AffineXCoord.GetEncoded();
var qy = q.AffineYCoord.GetEncoded();
var d = ecPrivateKeyParameters.D.ToByteArrayUnsigned();
// Convert the BouncyCastle key to a Native Key.
var msEcp = new ECParameters {Curve = ECCurve.NamedCurves.nistP256, Q = {X = qx, Y = qy}, D = d};
return ECDsa.Create(msEcp);
}
}
private string CreateJwt(ECDsa key, string keyId, string teamId)
{
var securityKey = new ECDsaSecurityKey(key) { KeyId = keyId };
var credentials = new SigningCredentials(securityKey, SecurityAlgorithms.EcdsaSha256);
var descriptor = new SecurityTokenDescriptor
{
IssuedAt = DateTime.Now,
Issuer = teamId,
SigningCredentials = credentials,
};
var handler = new JwtSecurityTokenHandler();
var encodedToken = handler.CreateEncodedJwt(descriptor);
return encodedToken;
}

It have tried the above on ASP.NET CORE 2.1 and 2.2 to no avail. The response I always got was "The message received was unexpected or badly formatted" with HttpVersion20 enabled, which made me doubt whether http2 implementation is concrete.
Below is what worked on ASP.NET CORE 3.0;
var teamId = "YOURTEAMID";
var keyId = "YOURKEYID";
try
{
//
var data = await System.IO.File.ReadAllTextAsync(Path.Combine(_environment.ContentRootPath, "apns/"+config.P8FileName));
var list = data.Split('\n').ToList();
var prk = list.Where((s, i) => i != 0 && i != list.Count - 1).Aggregate((agg, s) => agg + s);
//
var key = new ECDsaCng(CngKey.Import(Convert.FromBase64String(prk), CngKeyBlobFormat.Pkcs8PrivateBlob));
//
var token = CreateToken(key, keyId, teamId);
//
var deviceToken = "XXXXXXXXXXXXXXXXXXXXXXXXXXXX";
var url = string.Format("https://api.sandbox.push.apple.com/3/device/{0}", deviceToken);
var request = new HttpRequestMessage(HttpMethod.Post, url);
//
request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", token);
//
request.Headers.TryAddWithoutValidation("apns-push-type", "alert"); // or background
request.Headers.TryAddWithoutValidation("apns-id", Guid.NewGuid().ToString("D"));
//Expiry
//
request.Headers.TryAddWithoutValidation("apns-expiration", Convert.ToString(0));
//Send imediately
request.Headers.TryAddWithoutValidation("apns-priority", Convert.ToString(10));
//App Bundle
request.Headers.TryAddWithoutValidation("apns-topic", "com.xx.yy");
//Category
request.Headers.TryAddWithoutValidation("apns-collapse-id", "test");
//
var body = JsonConvert.SerializeObject(new
{
aps = new
{
alert = new
{
title = "Test",
body = "Sample Test APNS",
time = DateTime.Now.ToString()
},
badge = 1,
sound = "default"
},
acme2 = new string[] { "bang", "whiz" }
})
//
request.Version = HttpVersion.Version20;
//
using (var stringContent = new StringContent(body, Encoding.UTF8, "application/json"))
{
//Set Body
request.Content = stringContent;
_logger.LogInformation(request.ToString());
//
var handler = new HttpClientHandler();
//
handler.SslProtocols = SslProtocols.Tls12 | SslProtocols.Tls11 | SslProtocols.Tls;
//
handler.ServerCertificateCustomValidationCallback = (message, cert, chain, errors) => true;
//Continue
using (HttpClient client = new HttpClient(handler))
{
//
HttpResponseMessage resp = await client.SendAsync(request).ContinueWith(responseTask =>
{
return responseTask.Result;
//
});
//
_logger.LogInformation(resp.ToString());
//
if (resp != null)
{
string apnsResponseString = await resp.Content.ReadAsStringAsync();
//
handler.Dispose();
//ALL GOOD ....
return;
}
//
handler.Dispose();
}
}
}
catch (HttpRequestException e)
{
_logger.LogError(5, e.StackTrace, e);
}
For CreateToken() Refer Above Recommended solution by yaakov,

I has a problem like you. And i seen #gorniv answer. So it's work with me!
May be you can use: https://www.nuget.org/packages/Apple.Auth.Signin for it!
Goodluck!

Couldn't parse share document: error in LinkedIn REST API share

I try to call a share REST API with Hammock library function in my MVC 4 application.
Please see my code below
public ActionResult SharePost()
{
string content = "";
try
{
var credentials = new OAuthCredentials
{
ConsumerKey = "xxxxxxxxxxxxxx",
ConsumerSecret = "xxxxxxxxxxxxxxxx",
Token = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
TokenSecret = "xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
Verifier = verifier,
Type = OAuthType.AccessToken,
ParameterHandling = OAuthParameterHandling.HttpAuthorizationHeader,
SignatureMethod = OAuthSignatureMethod.HmacSha1,
Version = "1.0"
};
var client = new RestClient { Authority = "http://api.linkedin.com/v1", Credentials = credentials, Method = WebMethod.Post };
var request = new RestRequest { Path = "/people/~/shares" };
StringBuilder sbAppend = new StringBuilder();
sbAppend.AppendLine("<?xml version=1.0 encoding=UTF-8?>");
sbAppend.AppendLine("<share><comment>Check out the LinkedIn Share API!</comment><content><title>LinkedIn Developers Documentation On Using the Share API</title><description>Leverage the Share API to maximize engagement on user-generated content on LinkedIn</description><submitted-url>https://developer.linkedin.com/documents/share-api</submitted-url><submitted-image-url>http://m3.licdn.com/media/p/3/000/124/1a6/089a29a.png</submitted-image-url></content><visibility><code>anyone</code></visibility></share>");
client.AddHeader("Content-Type", "text/xml");
byte[] msg = Encoding.Default.GetBytes(sbAppend.ToString());
client.AddPostContent(msg);
RestResponse response = client.Request(request);
content = response.Content;
}
catch (Exception ex)
{
throw ex;
}
return Content(content);
}
But i get a error responce.content
Edit
I use double quotes in my xml header. but always shows the same error.
Is there any thing wrong.
I didn't see the post xml values in fiddller. Please see this image
Please help.

I found error in your XML you are missing ""
Try this
sbAppend.AppendLine('<?xml version="1.0" encoding="UTF-8"?>');

Http MultipartFormDataContent

I have been asked to do the following in C#:
/**
* 1. Create a MultipartPostMethod
* 2. Construct the web URL to connect to the SDP Server
* 3. Add the filename to be attached as a parameter to the MultipartPostMethod with parameter name "filename"
* 4. Execute the MultipartPostMethod
* 5. Receive and process the response as required
* /
I have written some code that has no errors, however, the file is not attached.
Can someone have a look at my C# code to see if I have written the code incorrectly?
Here is my code:
var client = new HttpClient();
const string weblinkUrl = "http://testserver.com/attach?";
var method = new MultipartFormDataContent();
const string fileName = "C:\file.txt";
var streamContent = new StreamContent(File.Open(fileName, FileMode.Open));
method.Add(streamContent, "filename");
var result = client.PostAsync(weblinkUrl, method);
MessageBox.Show(result.Result.ToString());

Posting MultipartFormDataContent in C# is simple but may be confusing the first time.
Here is the code that works for me when posting a .png .txt etc.
// 2. Create the url
string url = "https://myurl.com/api/...";
string filename = "myFile.png";
// In my case this is the JSON that will be returned from the post
string result = "";
// 1. Create a MultipartPostMethod
// "NKdKd9Yk" is the boundary parameter
using (var formContent = new MultipartFormDataContent("NKdKd9Yk"))
{
formContent.Headers.ContentType.MediaType = "multipart/form-data";
// 3. Add the filename C:\\... + fileName is the path your file
Stream fileStream = System.IO.File.OpenRead("C:\\Users\\username\\Pictures\\" + fileName);
formContent.Add(new StreamContent(fileStream), fileName, fileName);
using (var client = new HttpClient())
{
// Bearer Token header if needed
client.DefaultRequestHeaders.Add("Authorization", "Bearer " + _bearerToken);
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("multipart/form-data"));
try
{
// 4.. Execute the MultipartPostMethod
var message = await client.PostAsync(url, formContent);
// 5.a Receive the response
result = await message.Content.ReadAsStringAsync();
}
catch (Exception ex)
{
// Do what you want if it fails.
throw ex;
}
}
}
// 5.b Process the reponse Get a usable object from the JSON that is returned
MyObject myObject = JsonConvert.DeserializeObject<MyObject>(result);
In my case I need to do something with the object after it posts so I convert it to that object with JsonConvert.

I debugged this the problem is here:
method.Add(streamContent, "filename");
This 'Add' doesn't actually put the file in the BODY of Multipart Content.

I know this is an old post But to those searching for a solution, to provide a more direct answer, here's what I've found:
using System.Diagnostics;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks;
using System.Web;
using System.Web.Http;
public class UploadController : ApiController
{
public async Task<HttpResponseMessage> PostFormData()
{
// Check if the request contains multipart/form-data.
if (!Request.Content.IsMimeMultipartContent())
{
throw new HttpResponseException(HttpStatusCode.UnsupportedMediaType);
}
string root = HttpContext.Current.Server.MapPath("~/App_Data");
var provider = new MultipartFormDataStreamProvider(root);
try
{
// Read the form data.
await Request.Content.ReadAsMultipartAsync(provider);
// This illustrates how to get the file names.
foreach (MultipartFileData file in provider.FileData)
{
Trace.WriteLine(file.Headers.ContentDisposition.FileName);
Trace.WriteLine("Server file path: " + file.LocalFileName);
}
return Request.CreateResponse(HttpStatusCode.OK);
}
catch (System.Exception e)
{
return Request.CreateErrorResponse(HttpStatusCode.InternalServerError, e);
}
}
}
Here's where I found it:
http://www.asp.net/web-api/overview/advanced/sending-html-form-data,-part-2
For a more Elaborate implementation:
http://galratner.com/blogs/net/archive/2013/03/22/using-html-5-and-the-web-api-for-ajax-file-uploads-with-image-preview-and-a-progress-bar.aspx

Specify the third parameter which is a fileName.
Something like this:
method.Add(streamContent, "filename", "filename.pdf");