Client code to upload file via ASP.NET MVC WebApi - c#

I am trying to write code to upload file(s) by WinForm app to WebApi.
The WebApi code is like:
[HttpPost]
[Route("UploadEnvelope")]
[HostAuthentication(DefaultAuthenticationTypes.ExternalBearer)]
public Task<HttpResponseMessage> PostUploadEnvelope()
{
HttpRequestMessage request = this.Request;
if (!request.Content.IsMimeMultipartContent())
{
throw new HttpResponseException(HttpStatusCode.UnsupportedMediaType);
}
string root = System.Web.HttpContext.Current.Server.MapPath("~/App_Data/uploads");
var provider = new MultipartFormDataStreamProvider(root);
var task = request.Content.ReadAsMultipartAsync(provider).ContinueWith<HttpResponseMessage>(o =>
{
foreach (MultipartFileData fileData in provider.FileData)
{
if (string.IsNullOrEmpty(fileData.Headers.ContentDisposition.FileName))
{
return Request.CreateResponse(HttpStatusCode.NotAcceptable, "This request is not properly formatted");
}
string fileName = fileData.Headers.ContentDisposition.FileName;
if (fileName.StartsWith("\"") && fileName.EndsWith("\""))
{
fileName = fileName.Trim('"');
}
if (fileName.Contains(#"/") || fileName.Contains(#"\"))
{
fileName = Path.GetFileName(fileName);
}
File.Move(fileData.LocalFileName, Path.Combine(root, fileName));
}
return new HttpResponseMessage()
{
Content = new StringContent("Files uploaded.")
};
}
);
return task;
}
But I am not sure how to call it and pass file in a client app.
static string UploadEnvelope(string filePath, string token, string url)
{
using (var client = new HttpClient())
{
client.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", token);
// How to pass file here ???
var response = client.GetAsync(url + "/api/Envelope/UploadEnvelope").Result;
return response.Content.ReadAsStringAsync().Result;
}
}
Any help or suggestion is welcome. Thanks in advance!

First you are using Get method which is used for reading. You have to use Post instead.
Try the following:
public static string UploadEnvelope(string filePath,string token, string url)
{
using (var client = new HttpClient())
{
client.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", token);
using (var content = new MultipartFormDataContent("Envelope" + DateTime.Now.ToString(CultureInfo.InvariantCulture)))
{
content.Add(new StreamContent(new MemoryStream(File.ReadAllBytes(filePath))), "filename", "filename.ext");
using (var message = await client.PostAsync(url + "/api/Envelope/UploadEnvelope", content))
{
var input = await message.Content.ReadAsStringAsync();
return "success";
}
}
}
}
Note: For a large file you have to change configuration on IIS web.config.

Related

Bad Request when trying POST in ASP .NET

I have quite simple system: ASP .NET Core server which is hosted on domain.ru. In API controller there I have 2 methods:
[HttpGet("{id}")]
public string Get(int id)
{
try
{
using (FileStream fstream = new FileStream(string.Format(#"{0}\data{1}.txt", _path, id.ToString()), FileMode.OpenOrCreate))
{
byte[] array = System.Text.Encoding.Default.GetBytes(id.ToString());
fstream.Write(array, 0, array.Length);
return "It's ok!";
}
}
catch
{
return "Something went wrong";
}
}
[HttpPost]
public string Post(string resolvedString)
{
try
{
using (FileStream fstream = new FileStream(string.Format(#"{0}\dataPost.txt", _path), FileMode.OpenOrCreate))
{
byte[] array = System.Text.Encoding.Default.GetBytes(resolvedString);
fstream.Write(array, 0, array.Length);
return "It's ok!";
}
}
catch
{
return "Something went wrong";
}
}
So basically both of them are just creating text files in the _path directory. The part that i can't understand is when I try to call Get method by url domain.ru/api/values/1 I can see the file which was created in _path directory and I have response "It's ok!". That's how I call Get:
var client = new HttpClient();
client.BaseAddress = new Uri(uri);
HttpResponseMessage response = await client.GetAsync("api/values/1");
string result = await response.Content.ReadAsStringAsync();
textBox1.Text = result.ToString();
But when I try the same with Post I get either Bad Request when I do it with C# or "Something went wrong" when I do it with Postman.
That's the way how I call Post
var client = new HttpClient();
client.BaseAddress = new Uri(uri);
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
MultipartFormDataContent content = new MultipartFormDataContent();
StringContent str = new StringContent("1");
content.Add(str);
HttpResponseMessage response = await client.PostAsync("api/values/", content);
string returnString = await response.Content.ReadAsStringAsync();
MessageBox.Show(returnString);
Here's what the request shows when I try to manually debug this
And the most fun part. When I try to do all the same actions when my server is hosted on IIS (localserver) it works just fine! I' really don't know what I am doing wrong. Please, help.
UPD. Thanks to Jonathan, I asked my hoster to disable ModSecurity in Plesk and the above code started to work after replacing [HttpPost] by [HttpPost("{resolvedString}")]. So far so good!
Then I tried to send a zip archive to the server. Here is the server's controller code:
[HttpPost]
public string ImportZip(IFormFile file)
{
DirectoryInfo dirInfo = new DirectoryInfo(_extractPath);
try
{
foreach (FileInfo myfile in dirInfo.GetFiles())
{
myfile.Delete();
}
string path = _path + "tmp.zip";
if (Request.HasFormContentType)
{
var form = Request.Form;
foreach (var formFile in form.Files)
{
using (var fileStream = new FileStream(path, FileMode.Create))
{
formFile.CopyTo(fileStream);
}
ZipFile.ExtractToDirectory(_path + "tmp.zip", _extractPath);
}
}
return "It's OK! At least we've entered the method.";
}
catch
{
return "Oh no no no...";
}
}
And that's how I call it from the client:
string filepath = _zipFile;
string filename = _fileName;
var client = new HttpClient();
client.BaseAddress = new Uri(uri);
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
MultipartFormDataContent content = new MultipartFormDataContent();
ByteArrayContent fileContent = new ByteArrayContent(File.ReadAllBytes(filepath));
content.Add(fileContent, "file", filename);
HttpResponseMessage response = await client.PostAsync("File/ImportZip/", content);
string result = await response.Content.ReadAsStringAsync();
textBox1.Text = result;
Once again, it works as it should when I run both server and client on my computer. I can see downloaded archive and extracted files in destination directories.
But when I upload my server to hosting and try to execute my query once again, I get the same error:
an example of an error
Well, seems like I found an answer myself. Will leave it here so it can help someone (maybe me in the future).
Code of the client's send method:
string uri = "https://example.com/controller/action/";
string zipFile = #"C:\Path\To\Your\File.txt";
string response;
using (WebClient client = new WebClient())
{
response = Encoding.Default.GetString(client.UploadFile(uri, zipFile));
}
MessageBox.Show(response);
Here we just composing a request and sending a file. The path and url are hardcoded for ex.
Code of the server's save method:
[HttpPost]
public string ImportZip(IFormFile file)
{
try
{
string path = _path + "tmp.zip";
if (Request.HasFormContentType)
{
var form = Request.Form;
foreach (var formFile in form.Files)
{
using (var fileStream = new FileStream(path, FileMode.Create))
{
formFile.CopyTo(fileStream);
}
}
return "Done";
}
return "Empty request";
}
catch
{
return "No access";
}
}
As long as I send only one file and also I know its extension and I want it to be called "tmp", I hardcode it's name and extension. You can take file's default name/extension to save it as is.
Then I save all the files in request into a chosen _path directory.
Basically, that's it.

c# redirect post request

Trying to make a post request from one application to another using the same Form Data parameters that the first one received.
both application controller currently have same method:
public async Task<ActionResult> TestSet()
{
var inputString = Request.Form["inputString"];
var inputFile = Request.Files[0];
var resultString = await _service.Set(inputString, inputFile.FileName, inputFile.ContentType, inputFile.InputStream);
return new MyJsonResult(new
{
fileName = resultString
});
}
which return json string:
{"fileName": "someFileName.png"}
Trying to make the first method to be something like this
public async Task<ActionResult> TestSet()
{
var inputString = Request.Form["inputString"];
var inputFile = Request.Files[0];
if (!string.IsNullOrEmpty(_redirectUrl))
{
using (var client = new HttpClient())
{
HttpContent content = GetContentSomehow(this.Request); // this i have an issue with
var response = await client.PostAsync(_redirectUrl, content);
var responseString = await response.Content.ReadAsStringAsync();
return new MyJsonResult(responseString);
}
}
var resultString = await _service.Set(inputString, inputFile.FileName, inputFile.ContentType, inputFile.InputStream);
return new MyJsonResult(new
{
fileName = resultString
});
}
This could help to get ByteArrayContent for File only.
And this would probably work to get the non-file parameters into StringContent, but how to get both of them into single Content?
var jsonString = JsonConvert.SerializeObject(Request.Form.ToDictionary());
var content = new StringContent(jsonString, Encoding.UTF8, "application/json");
Solved this issue by cominig StringContent and StreamContent into MultipartFormDataContent
public static MultipartFormDataContent GetMultipartFormData(HttpRequestBase req)
{
var formData = new MultipartFormDataContent();
//formData.Headers.ContentType.MediaType = "multipart/form-data";
foreach (var row in req.Form.ToDictionary())
{
formData.Add(new StringContent(row.Value), row.Key);
}
var file = req.Files[0];
StreamContent fileStreamContent = new StreamContent(file.InputStream);
fileStreamContent.Headers.ContentType = new MediaTypeHeaderValue(file.ContentType);
formData.Add(fileStreamContent, file.FileName, file.FileName);
return formData;
}

HttpClient PostAsycn Always returns 404 Not Found but controller works with Postman and Javascript application

I have a Post Web Api Method in a controller and it's already working, I've been testing the method sending file from postman and a my own web application and it works but now I'm trying to send file from console application using Httpclient but always get 404.
Controller Method
public async Task<IHttpActionResult> Post()
{
FileServerConfig config = FileServerConfiguration.ObtenerConfiguracion(ConfigurationManager.AppSettings);
var path = string.Empty;
try
{
if (!Request.Content.IsMimeMultipartContent())
{
return StatusCode(HttpStatusCode.UnsupportedMediaType);
}
var filesReadToProvider = await Request.Content.ReadAsMultipartAsync();
foreach (var stream in filesReadToProvider.Contents)
{
IFileServerWrapper _cliente = FileServerConfiguration.CrearCliente(config);
var name = stream.Headers.ContentDisposition.FileName.Replace("\"", "").Replace("\\", "");
var fileUploaded = await _cliente.FileUpload(path, await stream.ReadAsStreamAsync(), name, false);
}
return Ok();
}
catch (HttpException httpex)
{
if (httpex.GetHttpCode() == (int)HttpStatusCode.Conflict)
{
return Conflict();
}
else
{
return InternalServerError(httpex);
}
}
catch (Exception ex)
{
return InternalServerError(ex);
}
}
Console application
static void Main(string[] args)
{
string filePath = #"C:\Software\itextTifftoPDF.rar";
using (var client = new HttpClient())
using (var content = new MultipartFormDataContent())
{
// Make sure to change API address
//client.BaseAddress = new Uri("http://localhost:80/FileServerAPI/");
client.DefaultRequestHeaders.Add("Accept-Language", "en-GB,en-US;q=0.8,en;q=0.6,ru;q=0.4");
client.DefaultRequestHeaders.CacheControl = CacheControlHeaderValue.Parse("no-cache");
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
// Add first file content
var fileContent1 = new ByteArrayContent(File.ReadAllBytes(filePath));
fileContent1.Headers.ContentDisposition = new ContentDispositionHeaderValue("form-data")
{
FileName = "itextTifftoPDF.rar"
};
content.Add(fileContent1);
// Make a call to Web API
var result = client.PostAsync("http://localhost/FileServerAPI/api/File", content).Result;
Console.WriteLine(result.StatusCode);
Console.ReadLine();
}
}
Finally I found a solution. the code is ugly because it was made just to be sure it works but I'll hope it may help others with the same problem.
string filePath = #"C:\temp\webdavtest.txt";
using (HttpClient httpClient = new HttpClient())
{
using (MultipartFormDataContent content =
new MultipartFormDataContent())
{
using (FileStream stream = File.Open(
filePath, FileMode.Open, FileAccess.Read))
{
using (StreamContent streamConent =
new StreamContent(stream))
{
content.Add(
streamConent, "webdavtest.txt", "webdavtest.txt");
var result = await httpClient.PostAsync("http://localhost:3983/api/File?path=/nivel5/", content);
return result.StatusCode.ToString();
}
}
}
}

Upload file to Pushbullet in Windows 10 app c#

I'm currently using Pushbullet API and need to upload a file.
I can successfully get an upload url as specified in the docs using this method:
public static async Task<Uploads> GetUploadUrl(string file_name, string file_type)
{
using (var client = new HttpClient())
{
client.DefaultRequestHeaders.Add("Access-Token", AccessToken);
var json = new JObject
{
["file_name"] = file_name,
["file_type"] = file_type
};
var result = await client.PostAsync(new Uri(_uploadUrl, UriKind.RelativeOrAbsolute), new HttpStringContent(json.ToString(), UnicodeEncoding.Utf8, "application/json"));
if (result.IsSuccessStatusCode)
{
var textresult = await result.Content.ReadAsStringAsync();
return JsonConvert.DeserializeObject<Uploads>(textresult);
}
}
return null;
}
The problem is when I try to upload the file. I'm currently using this method:
public static async Task<bool> UploadFile(StorageFile file, string upload_url)
{
try
{
System.Net.Http.HttpClient client = new System.Net.Http.HttpClient();
var content = new MultipartFormDataContent();
if (file != null)
{
var streamData = await file.OpenReadAsync();
var bytes = new byte[streamData.Size];
using (var dataReader = new DataReader(streamData))
{
await dataReader.LoadAsync((uint)streamData.Size);
dataReader.ReadBytes(bytes);
}
var streamContent = new ByteArrayContent(bytes);
content.Add(streamContent);
}
client.DefaultRequestHeaders.Add("Access-Token", AccessToken);
var response = await client.PostAsync(new Uri(upload_url, UriKind.Absolute), content);
if (response.IsSuccessStatusCode)
return true;
}
catch { return false; }
return false;
}
but I get a Http 400 error. What's the right way to upload a file using multipart/form-data in a UWP app?
HTTP 400 error indicates Bad Request, it means the request could not be understood by the server due to malformed syntax. In the other word, the request sent by the client doesn't follow server's rules.
Let's look at the document, and we can find in the example request it uses following parameter:
-F file=#cat.jpg
So in the request, we need to set the name for the uploaded file and the name should be "file". Besides, in this request, there is no need to use access token. So you can change your code like following:
public static async Task<bool> UploadFile(StorageFile file, string upload_url)
{
try
{
System.Net.Http.HttpClient client = new System.Net.Http.HttpClient();
var content = new MultipartFormDataContent();
if (file != null)
{
var streamData = await file.OpenReadAsync();
var bytes = new byte[streamData.Size];
using (var dataReader = new DataReader(streamData))
{
await dataReader.LoadAsync((uint)streamData.Size);
dataReader.ReadBytes(bytes);
}
var streamContent = new ByteArrayContent(bytes);
content.Add(streamContent, "file");
}
//client.DefaultRequestHeaders.Add("Access-Token", AccessToken);
var response = await client.PostAsync(new Uri(upload_url, UriKind.Absolute), content);
if (response.IsSuccessStatusCode)
return true;
}
catch { return false; }
return false;
}
Then your code should be able to work. You will get a 204 No Content response and UploadFile method will return true.

best practice for uploading images to azure blob

I am building a mobile app using xamarin while the server is hosted in azure. I am uploading images in the following way:
Client:
public static async Task<string> UploadImage (string url, byte[] imageData)
{
var content = new MultipartFormDataContent();
var fileContent = new ByteArrayContent(imageData);
fileContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")
{
FileName = Guid.NewGuid() + ".Png"
};
content.Add(fileContent);
using (var client = new HttpClient())
{
try
{
HttpResponseMessage msg = await client.PutAsync (url, content);
if(msg.StatusCode == System.Net.HttpStatusCode.OK)
{
return msg.Headers.GetValues ("ImageUrl").First();
}
return string.Empty;
}
catch (Exception ex)
{
return string.Empty;
}
}
}
and here is the server code:
[HttpPut]
public async Task<HttpResponseMessage> PostNewDishImage(string imageID)
{
try
{
_dishImagescontainer = BlobStorageHandler.GetContainer("dishuserimages");
if (!Request.Content.IsMimeMultipartContent("form-data"))
{
throw new HttpResponseException(Request.CreateResponse(HttpStatusCode.UnsupportedMediaType));
}
var provider = new BlobStorageProvider(_dishImagescontainer);
await Request.Content.ReadAsMultipartAsync(provider);
IList<string> urls = provider.Urls;
if (urls.Count > 0)
{
var response = new HttpResponseMessage();
response.StatusCode = HttpStatusCode.OK;
response.Headers.Add("ImageUrl", urls[0]);
return response;
}
return new HttpResponseMessage(HttpStatusCode.InternalServerError);
}
catch (System.Exception e)
{
return new HttpResponseMessage(HttpStatusCode.InternalServerError) { ReasonPhrase = e.ToString() };
}
}
It works fine but I don't like the way I am returning the new imageurl back to the client (through the http headers) I have tried some other ways but this is the best one so far :)
Does anyone have any better ideas?
Thanks
Returning data to the client in an HTTP header like that does have a bit of a smell. How about returning a DTO serialized to JSON?
An example DTO class:
public class ImageUploadResponse
{
public string Url { get; set; }
}
Then change your server side code to something like this:
var responseDto = new ImageUploadResponse { Url = urls[0] };
var response = new HttpResponseMessage(HttpStatusCode.OK)
{
Content = new StringContent(JsonConvert.SerializeObject(responseDto),
Encoding.UTF8, "application/json")
};
which will send the results back to the client in the content of the HTTP response as JSON. Then the client can parse the JSON into an object (or not) as you see fit. This approach will also be more friendly to making such a call from JavaScript in the future if you desire because the result is standard JSON.

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