Develop Reference

How to implement WebClient.UploadFileAsync with HttpClient? [duplicate]

Does anyone know how to use the HttpClient in .Net 4.5 with multipart/form-data upload?
I couldn't find any examples on the internet.

my result looks like this:
public static async Task<string> Upload(byte[] image)
{
using (var client = new HttpClient())
{
using (var content =
new MultipartFormDataContent("Upload----" + DateTime.Now.ToString(CultureInfo.InvariantCulture)))
{
content.Add(new StreamContent(new MemoryStream(image)), "bilddatei", "upload.jpg");
using (
var message =
await client.PostAsync("http://www.directupload.net/index.php?mode=upload", content))
{
var input = await message.Content.ReadAsStringAsync();
return !string.IsNullOrWhiteSpace(input) ? Regex.Match(input, #"http://\w*\.directupload\.net/images/\d*/\w*\.[a-z]{3}").Value : null;
}
}
}
}

It works more or less like this (example using an image/jpg file):
async public Task<HttpResponseMessage> UploadImage(string url, byte[] ImageData)
{
var requestContent = new MultipartFormDataContent();
// here you can specify boundary if you need---^
var imageContent = new ByteArrayContent(ImageData);
imageContent.Headers.ContentType =
MediaTypeHeaderValue.Parse("image/jpeg");
requestContent.Add(imageContent, "image", "image.jpg");
return await client.PostAsync(url, requestContent);
}
(You can requestContent.Add() whatever you want, take a look at the HttpContent descendant to see available types to pass in)
When completed, you'll find the response content inside HttpResponseMessage.Content that you can consume with HttpContent.ReadAs*Async.

This is an example of how to post string and file stream with HTTPClient using MultipartFormDataContent. The Content-Disposition and Content-Type need to be specified for each HTTPContent:
Here's my example. Hope it helps:
private static void Upload()
{
using (var client = new HttpClient())
{
client.DefaultRequestHeaders.Add("User-Agent", "CBS Brightcove API Service");
using (var content = new MultipartFormDataContent())
{
var path = #"C:\B2BAssetRoot\files\596086\596086.1.mp4";
string assetName = Path.GetFileName(path);
var request = new HTTPBrightCoveRequest()
{
Method = "create_video",
Parameters = new Params()
{
CreateMultipleRenditions = "true",
EncodeTo = EncodeTo.Mp4.ToString().ToUpper(),
Token = "x8sLalfXacgn-4CzhTBm7uaCxVAPjvKqTf1oXpwLVYYoCkejZUsYtg..",
Video = new Video()
{
Name = assetName,
ReferenceId = Guid.NewGuid().ToString(),
ShortDescription = assetName
}
}
};
//Content-Disposition: form-data; name="json"
var stringContent = new StringContent(JsonConvert.SerializeObject(request));
stringContent.Headers.Add("Content-Disposition", "form-data; name=\"json\"");
content.Add(stringContent, "json");
FileStream fs = File.OpenRead(path);
var streamContent = new StreamContent(fs);
streamContent.Headers.Add("Content-Type", "application/octet-stream");
//Content-Disposition: form-data; name="file"; filename="C:\B2BAssetRoot\files\596090\596090.1.mp4";
streamContent.Headers.Add("Content-Disposition", "form-data; name=\"file\"; filename=\"" + Path.GetFileName(path) + "\"");
content.Add(streamContent, "file", Path.GetFileName(path));
//content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment");
Task<HttpResponseMessage> message = client.PostAsync("http://api.brightcove.com/services/post", content);
var input = message.Result.Content.ReadAsStringAsync();
Console.WriteLine(input.Result);
Console.Read();
}
}
}

Try this its working for me.
private static async Task<object> Upload(string actionUrl)
{
Image newImage = Image.FromFile(#"Absolute Path of image");
ImageConverter _imageConverter = new ImageConverter();
byte[] paramFileStream= (byte[])_imageConverter.ConvertTo(newImage, typeof(byte[]));
var formContent = new MultipartFormDataContent
{
// Send form text values here
{new StringContent("value1"),"key1"},
{new StringContent("value2"),"key2" },
// Send Image Here
{new StreamContent(new MemoryStream(paramFileStream)),"imagekey","filename.jpg"}
};
var myHttpClient = new HttpClient();
var response = await myHttpClient.PostAsync(actionUrl.ToString(), formContent);
string stringContent = await response.Content.ReadAsStringAsync();
return response;
}

Here is another example on how to use HttpClient to upload a multipart/form-data.
It uploads a file to a REST API and includes the file itself (e.g. a JPG) and additional API parameters. The file is directly uploaded from local disk via FileStream.
See here for the full example including additional API specific logic.
public static async Task UploadFileAsync(string token, string path, string channels)
{
// we need to send a request with multipart/form-data
var multiForm = new MultipartFormDataContent();
// add API method parameters
multiForm.Add(new StringContent(token), "token");
multiForm.Add(new StringContent(channels), "channels");
// add file and directly upload it
FileStream fs = File.OpenRead(path);
multiForm.Add(new StreamContent(fs), "file", Path.GetFileName(path));
// send request to API
var url = "https://slack.com/api/files.upload";
var response = await client.PostAsync(url, multiForm);
}

Here's a complete sample that worked for me. The boundary value in the request is added automatically by .NET.
var url = "http://localhost/api/v1/yourendpointhere";
var filePath = #"C:\path\to\image.jpg";
HttpClient httpClient = new HttpClient();
MultipartFormDataContent form = new MultipartFormDataContent();
FileStream fs = File.OpenRead(filePath);
var streamContent = new StreamContent(fs);
var imageContent = new ByteArrayContent(streamContent.ReadAsByteArrayAsync().Result);
imageContent.Headers.ContentType = MediaTypeHeaderValue.Parse("multipart/form-data");
form.Add(imageContent, "image", Path.GetFileName(filePath));
var response = httpClient.PostAsync(url, form).Result;

Example with preloader Dotnet 3.0 Core
ProgressMessageHandler processMessageHander = new ProgressMessageHandler();
processMessageHander.HttpSendProgress += (s, e) =>
{
if (e.ProgressPercentage > 0)
{
ProgressPercentage = e.ProgressPercentage;
TotalBytes = e.TotalBytes;
progressAction?.Invoke(progressFile);
}
};
using (var client = HttpClientFactory.Create(processMessageHander))
{
var uri = new Uri(transfer.BackEndUrl);
client.DefaultRequestHeaders.Authorization =
new AuthenticationHeaderValue("Bearer", AccessToken);
using (MultipartFormDataContent multiForm = new MultipartFormDataContent())
{
multiForm.Add(new StringContent(FileId), "FileId");
multiForm.Add(new StringContent(FileName), "FileName");
string hash = "";
using (MD5 md5Hash = MD5.Create())
{
var sb = new StringBuilder();
foreach (var data in md5Hash.ComputeHash(File.ReadAllBytes(FullName)))
{
sb.Append(data.ToString("x2"));
}
hash = result.ToString();
}
multiForm.Add(new StringContent(hash), "Hash");
using (FileStream fs = File.OpenRead(FullName))
{
multiForm.Add(new StreamContent(fs), "file", Path.GetFileName(FullName));
var response = await client.PostAsync(uri, multiForm);
progressFile.Message = response.ToString();
if (response.IsSuccessStatusCode) {
progressAction?.Invoke(progressFile);
} else {
progressErrorAction?.Invoke(progressFile);
}
response.EnsureSuccessStatusCode();
}
}
}

I'm adding a code snippet which shows on how to post a file to an API which has been exposed over DELETE http verb. This is not a common case to upload a file with DELETE http verb but it is allowed. I've assumed Windows NTLM authentication for authorizing the call.
The problem that one might face is that all the overloads of HttpClient.DeleteAsync method have no parameters for HttpContent the way we get it in PostAsync method
var requestUri = new Uri("http://UrlOfTheApi");
using (var streamToPost = new MemoryStream("C:\temp.txt"))
using (var fileStreamContent = new StreamContent(streamToPost))
using (var httpClientHandler = new HttpClientHandler() { UseDefaultCredentials = true })
using (var httpClient = new HttpClient(httpClientHandler, true))
using (var requestMessage = new HttpRequestMessage(HttpMethod.Delete, requestUri))
using (var formDataContent = new MultipartFormDataContent())
{
formDataContent.Add(fileStreamContent, "myFile", "temp.txt");
requestMessage.Content = formDataContent;
var response = httpClient.SendAsync(requestMessage).GetAwaiter().GetResult();
if (response.IsSuccessStatusCode)
{
// File upload was successfull
}
else
{
var erroResult = response.Content.ReadAsStringAsync().GetAwaiter().GetResult();
throw new Exception("Error on the server : " + erroResult);
}
}
You need below namespaces at the top of your C# file:
using System;
using System.Net;
using System.IO;
using System.Net.Http;
P.S. You are seeing a number of using blocks(IDisposable pattern) in the above code snippet which doesn't look very clean. Unfortunately, the syntax of using construct doesn't support initializing multiple variables in single statement.

X509Certificate clientKey1 = null;
clientKey1 = new X509Certificate(AppSetting["certificatePath"],
AppSetting["pswd"]);
string url = "https://EndPointAddress";
FileStream fs = File.OpenRead(FilePath);
var streamContent = new StreamContent(fs);
var FileContent = new ByteArrayContent(streamContent.ReadAsByteArrayAsync().Result);
FileContent.Headers.ContentType = MediaTypeHeaderValue.Parse("ContentType");
var handler = new WebRequestHandler();
handler.ClientCertificateOptions = ClientCertificateOption.Manual;
handler.ClientCertificates.Add(clientKey1);
handler.ServerCertificateValidationCallback = (httpRequestMessage, cert, cetChain, policyErrors) =>
{
return true;
};
using (var client = new HttpClient(handler))
{
// Post it
HttpResponseMessage httpResponseMessage = client.PostAsync(url, FileContent).Result;
if (!httpResponseMessage.IsSuccessStatusCode)
{
string ss = httpResponseMessage.StatusCode.ToString();
}
}

public async Task<object> PassImageWithText(IFormFile files)
{
byte[] data;
string result = "";
ByteArrayContent bytes;
MultipartFormDataContent multiForm = new MultipartFormDataContent();
try
{
using (var client = new HttpClient())
{
using (var br = new BinaryReader(files.OpenReadStream()))
{
data = br.ReadBytes((int)files.OpenReadStream().Length);
}
bytes = new ByteArrayContent(data);
multiForm.Add(bytes, "files", files.FileName);
multiForm.Add(new StringContent("value1"), "key1");
multiForm.Add(new StringContent("value2"), "key2");
var res = await client.PostAsync(_MEDIA_ADD_IMG_URL, multiForm);
}
}
catch (Exception e)
{
throw new Exception(e.ToString());
}
return result;
}

Get the file postion of each file into a stream

I am sending multiples files from my web api but I want to read each part of the stream to convert him into a byte array , then at the end I have a list of byte[], and I can save each files:
[Route("GetFiles")]
public HttpResponseMessage GetFile([FromUri] List<string> filesNames)
{
HttpResponseMessage response = new HttpResponseMessage(HttpStatusCode.BadRequest);
if (filesNames.Count == 0)
return Request.CreateResponse(HttpStatusCode.BadRequest);
var content = new MultipartContent();
filesNames.ForEach(delegate (string fileName)
{
string filePath = System.Web.Hosting.HostingEnvironment.MapPath("~/Uploads/" + fileName);
byte[] pdf = File.ReadAllBytes(filePath);
content.Add(new ByteArrayContent(pdf));
response.Headers.Add(fileName, fileName);
});
var files = JsonConvert.SerializeObject(content);
response.Content.Headers.ContentDisposition = new System.Net.Http.Headers.ContentDispositionHeaderValue("attachment");
response.Content.Headers.ContentType = new MediaTypeHeaderValue("application/pdf");
response = Request.CreateResponse(HttpStatusCode.OK, content);
return response;
}
Here is how I get one file into a stream, then convert him into a byte array to report the process percentage :
public static async Task<byte[]> CreateDownloadTaskForFile(string urlToDownload, IProgress<DownloadBytesProgress> progessReporter)
{
int receivedBytes = 0;
int totalBytes = 0;
WebClient client = new WebClient();
using (var stream = await client.OpenReadTaskAsync(urlToDownload))
{
byte[] buffer = new byte[BufferSize];
totalBytes = Int32.Parse(client.ResponseHeaders[HttpResponseHeader.ContentLength]);
using (MemoryStream memoryStream = new MemoryStream())
{
for (; ; )
{
int bytesRead = await stream.ReadAsync(buffer, 0, buffer.Length);
memoryStream.Write(buffer, 0, buffer.Length);
if (bytesRead == 0)
{
await Task.Yield();
break;
}
receivedBytes += bytesRead;
if (progessReporter != null)
{
DownloadBytesProgress args = new DownloadBytesProgress(urlToDownload, receivedBytes, totalBytes);
progessReporter.Report(args);
}
}
return memoryStream.ToArray();
}
}
}
How do I get the position of a stream for each files send ?
Update :
I made a HttpResponseMessage like this :
[Route("GetFiles")]
public HttpResponseMessage GetFiles([FromUri] List<string> filesNames)
{
HttpResponseMessage response = new HttpResponseMessage(HttpStatusCode.BadRequest);
if (filesNames.Count == 0)
return Request.CreateResponse(HttpStatusCode.BadRequest);
var content = new MultipartFormDataContent();
filesNames.ForEach(delegate (string fileName)
{
string filePath = System.Web.Hosting.HostingEnvironment.MapPath("~/Uploads/" + fileName);
byte[] pdf = File.ReadAllBytes(filePath);
content.Add(new ByteArrayContent(pdf), fileName);
});
response = Request.CreateResponse(HttpStatusCode.OK, content);
response.Content.Headers.ContentDisposition = new System.Net.Http.Headers.ContentDispositionHeaderValue("attachment");
response.Content.Headers.ContentType = new MediaTypeHeaderValue("application/pdf");
return response;
}
But from my device side : When I am trying to run the request But there is nothing on the response content :
using (var httpResponseMessage = await httpClient.GetAsync(urlToDownload + filesNamesArg))
{
var streamProvider = new MultipartMemoryStreamProvider();
streamProvider = httpResponseMessage.Content.ReadAsMultipartAsync().Result;
}
Could you show me some docs or advice ?

What?
This answer provides a 100% working example for:
Serving multiple files as a single response from a web API using multipart/mixed content type,
Reading the file contents on the client by parsing the response of the web API implemented in 1
I hope this helps.
Server:
The server application is a .Net 4.7.2 MVC project with web API support.
The following method is implemented in an ApiController and returns all the files under the ~/Uploads folder in a single response.
Please make note of the use of Request.RegisterForDispose extension to register the FileStreams for later disposal.
public async Task<HttpResponseMessage> GetFiles()
{
string filesPath = System.Web.Hosting.HostingEnvironment.MapPath("~/Uploads");
List<string> fileNames = new List<string>(Directory.GetFiles(filesPath));
var content = new MultipartContent();
fileNames.ForEach(delegate(string fileName)
{
var fileContent = new StreamContent(File.OpenRead(fileName));
Request.RegisterForDispose(fileContent);
fileContent.Headers.ContentType = System.Net.Http.Headers.MediaTypeHeaderValue.Parse("image/jpeg");
content.Add(fileContent);
});
var response = new HttpResponseMessage();
response.Content = content;
return response;
}
The response's Content-Type header shows as Content-Type: multipart/mixed; boundary="7aeff3b4-2e97-41b2-b06f-29a8c23a7aa7" and each file is packed in different blocks separated by the boundary.
Client:
The client application is a .Net Core 3.0.1 console application.
Please note the synchronous usage of the async methods. This can be easily changed to asynchronous using await, but implemented like this for simplicity:
using System;
using System.IO;
using System.Net.Http;
namespace console
{
class Program
{
static void Main(string[] args)
{
using (HttpClient httpClient = new HttpClient())
{
using (HttpResponseMessage httpResponseMessage = httpClient.GetAsync("http://localhost:60604/api/GetImage/GetFiles").Result)
{
var content = (HttpContent)new StreamContent(httpResponseMessage.Content.ReadAsStreamAsync().Result);
content.Headers.ContentType = httpResponseMessage.Content.Headers.ContentType;
MultipartMemoryStreamProvider multipartResponse = new MultipartMemoryStreamProvider();
content.ReadAsMultipartAsync(multipartResponse);
for(int i = 0; i< multipartResponse.Contents.Count;i++)
{
Stream contentStream = multipartResponse.Contents[i].ReadAsStreamAsync().Result;
Console.WriteLine("Content {0}, length {1}", i, contentStream.Length);
}
}
}
}
}
}

Post string and bytearray to server

I have done POSTING and GETing from server using string post data, but now i have the next WebService:
submitFeedback(String token, String subject, String body, byte[] photo, byte[] video);
private void PostFeedbackData()
{
if (GS.online != true)
{
MessageBox.Show(GS.translations["ErrorMsg0"]);
}
else
{
HttpWebRequest request = HttpWebRequest.CreateHttp("https://****/feedback");
request.Method = "POST";
request.BeginGetRequestStream(new AsyncCallback(GetRequestStreamCallback), request);
}
}
void GetRequestStreamCallback(IAsyncResult callbackResult)
{
HttpWebRequest myRequest = (HttpWebRequest)callbackResult.AsyncState;
// End the stream request operation
Stream postStream = myRequest.EndGetRequestStream(callbackResult);
// Create the post data
string postData = "";
Deployment.Current.Dispatcher.BeginInvoke(() =>
{
postData = "{\"jsonrpc\": \"2.0\", \"method\": \"getUserSchedule\", \"params\":[" + "\"" + (App.Current as App).UserToken + "\",\"" + FeedbackTitle.Text + "\",\"" + FeedbackContent.Text + "\",\"" + imageBytes + "\"], \"id\": 1}";
byte[] byteArray = Encoding.UTF8.GetBytes(postData);
// Add the post data to the web request
postStream.Write(byteArray, 0, byteArray.Length);
postStream.Close();
// Start the web request
myRequest.BeginGetResponse(new AsyncCallback(GetResponsetStreamCallback), myRequest);
});
}
Look at post data - it is a string, i can't place there imageBytes array. How to do it?

Is there any reason for using HttpWebRequest ?
I am asking that because i think that the correct way of sending files to a service is by multipartform data. With HttpWebRequest you have to manually implement that.
Here is an example that is using Microsoft's HttpClient that might work for you:
public async Task<string> submitFeedback(String token, String subject, String body, byte[] photo, byte[] video) {
var client = new HttpClient();
var content = new MultipartFormDataContent();
// Some APIs do not support quotes in boundary field
foreach (var param in content.Headers.ContentType.Parameters.Where(param => param.Name.Equals("boundary")))
param.Value = param.Value.Replace("\"", String.Empty);
var tok = new StringContent(token);
content.Add(tok, "\"token\"");
var sub = new StringContent(subject);
content.Add(tok, "\"subject\"");
// Add the Photo
var photoContent = new StreamContent(new MemoryStream(photo));
photoContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("form-data")
{
Name = "\"photo\"",
FileName = "\"photoname.jpg\""
};
photoContent.Headers.ContentType = MediaTypeHeaderValue.Parse("image/jpeg");
content.Add(photoContent);
// Add the video
var videoContent = new StreamContent(new MemoryStream(video));
videoContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("form-data")
{
Name = "\"video\"",
FileName = "\"videoname.jpg\""
};
videoContent.Headers.ContentType = MediaTypeHeaderValue.Parse("video/mp4");
content.Add(videoContent);
HttpResponseMessage resp;
try {
resp = await client.PostAsync("SERVER_URL_GOES_HERE", content);
}
catch (Exception e)
{
return "EXCEPTION ERROR";
}
if (resp.StatusCode != HttpStatusCode.OK)
{
return resp.StatusCode.ToString();
}
var reponse = await resp.Content.ReadAsStringAsync();
return reponse;
}
Change accordingly.
Note: HttpClient is also using HttpWebRequest under the hood.
Also I don't think its a good idea to have the UI thread making the request. That makes no sense since you are blocking the interface and making the async theory useless.

Converting ordinary Http Post web request with Async and Await

How I can convert my traditional HttpWebRequest "POST" call with Async / Await pattern, Here with this I am attaching my current code, Any one please help me to convert this code using Async / Await pattern for windows phone 8.
public void GetEnvironmentVariables(Action<Credentials> getResultCallback, Action<Exception> getErrorCallback)
{
CredentialsCallback = getResultCallback;
ErrorCallback = getErrorCallback;
var uri = new Uri(BaseUri);
var request = (HttpWebRequest)WebRequest.Create(uri);
request.Method = "POST";
request.ContentType = "application/json";
var jsonObject = new JObject
{
new JProperty("apiKey",_api),
new JProperty("affiliateId",_affid),
};
var serializedResult = JsonConvert.SerializeObject(jsonObject);
byte[] requestBody = Encoding.UTF8.GetBytes(serializedResult);
request.BeginGetRequestStream(GetRequestStreamCallback, new object[] { request, requestBody });
}
private void GetRequestStreamCallback(IAsyncResult asynchronousResult)
{
var request = (HttpWebRequest)((object[])asynchronousResult.AsyncState)[0];
using (var postStream = request.EndGetRequestStream(asynchronousResult))
{
var byteArray = (byte[])((object[])asynchronousResult.AsyncState)[1];
// Write to the request stream.
postStream.Write(byteArray, 0, byteArray.Length);
}
request.BeginGetResponse(GetResponseCallback, request);
}
private void GetResponseCallback(IAsyncResult asynchronousResult)
{
var request = (HttpWebRequest)asynchronousResult.AsyncState;
try
{
var response = (HttpWebResponse)request.EndGetResponse(asynchronousResult);
if (response != null)
{
var reader = new StreamReader(response.GetResponseStream());
string responseString = reader.ReadToEnd();
Credentails = JsonConvert.DeserializeObject<Credentials>(responseString);
if (Credentails != null && string.IsNullOrEmpty(Credentails.Err))
CredentialsCallback(Credentails);
else
{
if (Credentails != null)
ErrorCallback(new Exception(string.Format("Error Code : {0}", StorageCredentails.Err)));
}
}
}
catch (WebException we)
{
var reader = new StreamReader(we.Response.GetResponseStream());
string responseString = reader.ReadToEnd();
Debug.WriteLine(responseString);
ErrorCallback(we);
}
}

Since Windows Phone 8 doesn't seem to offer the TAP methods you need such as GetRequestStreamAsync the first thing to do is write a little wrapper to provide them for yourself:
public static class WebRequestAsyncExtensions
{
public static Task<Stream> GetRequestStreamAsync(this WebRequest request)
{
return Task.Factory.FromAsync<Stream>(
request.BeginGetRequestStream, request.EndGetRequestStream, null);
}
public static Task<WebResponse> GetResponseAsync(this WebRequest request)
{
return Task.Factory.FromAsync<WebResponse>(
request.BeginGetResponse, request.EndGetResponse, null);
}
}
Note the use of Task.Factory.FromAsync - this is the preferred way to get an await-friendly wrapper around an APM-based async API such as those offered by WebRequest. This is far more efficient than using Task.Factory.StartNew as suggested by someone else, because that would spin up a new thread, whereas this won't need to.
With this in place, you can now write your code in the same way you would on platforms where these TAP-style methods are available (e.g. Windows 8 store apps, desktop apps, etc.):
public async Task GetEnvironmentVariablesAsync(Action<Credentials> getResultCallback, Action<Exception> getErrorCallback)
{
CredentialsCallback = getResultCallback;
ErrorCallback = getErrorCallback;
var uri = new Uri(BaseUri);
var request = (HttpWebRequest) WebRequest.Create(uri);
request.Method = "POST";
request.ContentType = "application/json";
var jsonObject = new JObject
{
new JProperty("apiKey",_api),
new JProperty("affiliateId",_affid),
};
var serializedResult = JsonConvert.SerializeObject(jsonObject);
byte[] requestBody = Encoding.UTF8.GetBytes(serializedResult);
// ASYNC: using awaitable wrapper to get request stream
using (var postStream = await request.GetRequestStreamAsync())
{
// Write to the request stream.
// ASYNC: writing to the POST stream can be slow
await postStream.WriteAsync(requestBody, 0, requestBody.Length);
}
try
{
// ASYNC: using awaitable wrapper to get response
var response = (HttpWebResponse) await request.GetResponseAsync();
if (response != null)
{
var reader = new StreamReader(response.GetResponseStream());
// ASYNC: using StreamReader's async method to read to end, in case
// the stream i slarge.
string responseString = await reader.ReadToEndAsync();
Credentails = JsonConvert.DeserializeObject<Credentials>(responseString);
if (Credentails != null && string.IsNullOrEmpty(Credentails.Err))
CredentialsCallback(Credentails);
else
{
if (Credentails != null)
ErrorCallback(new Exception(string.Format("Error Code : {0}", StorageCredentails.Err)));
}
}
}
catch (WebException we)
{
var reader = new StreamReader(we.Response.GetResponseStream());
string responseString = reader.ReadToEnd();
Debug.WriteLine(responseString);
ErrorCallback(we);
}
}
Note the four lines with // ASYNC: comments - these show where I've made changes. I've collapsed your method down to one, because that's a) possible once you're using async and await and b) much easier than trying to pass things from one method to the next using state arguments.
Notice that the second and fourth of these actually makes async some things you were previously doing synchronously: writing data into the request stream, and reading data out of the response stream. For a small request this probably doesn't matter, but if large amounts of data are being transferred, a synchronous call to Write or ReadToEnd may block. Fortunately, although Windows Phone 8 appears to be missing the TAP methods on WebRequest, it does offer them on Stream and StreamReader so this works without needing to write any extension methods.

I'm new to the community, so here goes my first post. In this case, you can return anytype using a generic Task. This has worked well for me in the past.
Server Side
public class MyController : ApiController
{
public Task<string> PostAsync()
{
return Task.Factory.StartNew(() =>
{
return "populate me with any type and data, but change the type in the response signature.";
});
}
}
Client Side
public class HomeController : Controller
{
public Task<ViewResult> Index()
{
return Task.Factory.StartNew(() =>
{
var model = "use a provider, get some data, or something";
return View(model);
});
}
}

This should do the job:
public async void GetEnvironmentVariables(Action<Credentials> getResultCallback, Action<Exception> getErrorCallback) {
CredentialsCallback = getResultCallback;
ErrorCallback = getErrorCallback;
var uri = new Uri(BaseUri);
var request = (HttpWebRequest)WebRequest.Create(uri);
request.Method = "POST";
request.ContentType = "application/json";
var jsonObject = new JObject {
new JProperty("apiKey", _api),
new JProperty("affiliateId", _affid),
};
var serializedResult = JsonConvert.SerializeObject(jsonObject);
var requestBody = Encoding.UTF8.GetBytes(serializedResult);
var requestStream = request.GetRequestStream();
requestStream.Write(requestBody, 0, requestBody.Length);
await GetResponse(request);
}
private async Task GetResponse(WebRequest request) {
Stream resStream = null;
try {
var response = await request.GetResponseAsync();
if (response == null) {
return;
}
resStream = response.GetResponseStream();
if (resStream == null) {
return;
}
var reader = new StreamReader(resStream);
var responseString = await reader.ReadToEndAsync();
Credentails = JsonConvert.DeserializeObject<Credentials>(responseString);
if (Credentails != null && string.IsNullOrEmpty(Credentails.Err)) {
CredentialsCallback(Credentails);
}
else {
if (Credentails != null) {
ErrorCallback(new Exception(string.Format("Error Code : {0}", StorageCredentails.Err)));
}
}
}
catch (WebException we) {
if (resStream != null) {
var reader = new StreamReader(resStream);
var responseString = reader.ReadToEnd();
Debug.WriteLine(responseString);
}
ErrorCallback(we);
}
}

Uploading to imgur.com

Imgur is a image uploading website who offers an API to upload
My code looks exactly like the PHP code they provide as an example. however, in their php code they are http_build_query($pvars);
It seems like they are URLEncoding their query before posting it. edit: Note that I have changed to full .NET 3.5 rather then the client profile. This gave me access to system.web so I used httputliity.urlencode(). This made the api return a "fail" with a "no image was sent". If I don't encode then the API returns an "okay" with a link to the picture, however no picture is uploaded (like a blank file).
How can I fix my code to work properly against their API?
Image image = Image.FromFile("C:\\Users\\Affan\\Pictures\\1509310.jpg");
MemoryStream ms = new MemoryStream();
// Convert Image to byte[]
image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
byte[] imageBytes = ms.ToArray();
WebRequest wb = WebRequest.Create(new Uri("http://imgur.com/api/upload.xml"));
wb.ContentType = "application/x-www-form-urlencoded";
wb.Method = "POST";
wb.Timeout = 10000;
Console.WriteLine(imageBytes.Length);
string parameters = "key=433a1bf4743dd8d7845629b95b5ca1b4&image=" + Convert.ToBase64String(imageBytes);
Console.WriteLine("parameters: " + parameters.Length);
System.Text.UTF8Encoding encoding = new System.Text.UTF8Encoding();
byte[] bytes = encoding.GetBytes(parameters);
// byte[] bytes = Convert.FromBase64String(parameters);
System.IO.Stream os = null;
try { // send the Post
wb.ContentLength = bytes.Length; //Count bytes to send
os = wb.GetRequestStream();
os.Write(bytes, 0, bytes.Length); //Send it
} catch (WebException ex) {
MessageBox.Show(ex.Message, "HttpPost: Request error");
Console.WriteLine(ex.Message);
} finally {
if (os != null) {
// os.Close();
}
}
try { // get the response
WebResponse webResponse = wb.GetResponse();
StreamReader sr = new StreamReader(webResponse.GetResponseStream());
//MessageBox.Show(sr.ReadToEnd().Trim());
Console.WriteLine(sr.ReadToEnd().Trim());
} catch (WebException ex) {
MessageBox.Show(ex.Message, "HttpPost: Response error");
}

I've just uploaded this image
using this code:
using (var w = new WebClient())
{
var values = new NameValueCollection
{
{ "key", "433a1bf4743dd8d7845629b95b5ca1b4" },
{ "image", Convert.ToBase64String(File.ReadAllBytes(#"hello.png")) }
};
byte[] response = w.UploadValues("http://imgur.com/api/upload.xml", values);
Console.WriteLine(XDocument.Load(new MemoryStream(response)));
}
You might want to change your API key now :-)
The output was:
<rsp stat="ok">
<image_hash>IWg2O</image_hash>
<delete_hash>fQAXiR2Fdq</delete_hash>
<original_image>http://i.imgur.com/IWg2O.png</original_image>
<large_thumbnail>http://i.imgur.com/IWg2Ol.jpg</large_thumbnail>
<small_thumbnail>http://i.imgur.com/IWg2Os.jpg</small_thumbnail>
<imgur_page>http://imgur.com/IWg2O</imgur_page>
<delete_page>http://imgur.com/delete/fQAXiR2Fdq</delete_page>
</rsp>

Here's an updated version of dtb's answer for the v3 API using anonymous uploading (you need to register your app at http://api.imgur.com/ to get your client ID):
using (var w = new WebClient())
{
string clientID = "<<INSERT YOUR ID HERE>>";
w.Headers.Add("Authorization", "Client-ID " + clientID);
var values = new NameValueCollection
{
{ "image", Convert.ToBase64String(File.ReadAllBytes(#"hello.png")) }
};
byte[] response = w.UploadValues("https://api.imgur.com/3/upload.xml", values);
Console.WriteLine(XDocument.Load(new MemoryStream(response)));
}
And the response is now like this (see http://api.imgur.com/models/image):
<data success="1" status="200">
<id>SbBGk</id>
<title/>
<description/>
<datetime>1341533193</datetime>
<type>image/jpeg</type>
<animated>false</animated>
<width>2559</width>
<height>1439</height>
<size>521916</size>
<views>1</views>
<bandwidth>521916</bandwidth>
<deletehash>eYZd3NNJHsbreD1</deletehash>
<section/>
<link>http://i.imgur.com/SbBGk.jpg</link>
</data>

I Guess that the dtb solution is deprecated
using (var w = new WebClient())
{
var values = new NameValueCollection
{
{"image", Convert.ToBase64String(imageData)},
{"type", "base64"}
};
w.Headers.Add("Authorization", "Client-ID xxxxxxxxx");
var response = w.UploadValues("https://api.imgur.com/3/image", values);
}
another way to do:
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("https://api.imgur.com/3/image");
request.Headers.Add("Authorization", "Client-ID xxxxxxx");
request.Method = "POST";
ASCIIEncoding enc = new ASCIIEncoding();
string postData = Convert.ToBase64String(imageData);
byte[] bytes = enc.GetBytes(postData);
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = bytes.Length;
Stream writer = request.GetRequestStream();
writer.Write(bytes, 0, bytes.Length);
HttpWebResponse response = (HttpWebResponse)request.GetResponse();