Request.Content.IsMimeMultipartContent() fails - c#

I'm trying to upload a file using the Html2 input type="file" and an angular2 http.post request. When the request reaches the web api, it fails in the
Request.Content.IsMimeMultipartContent()
It doesn't fail when submitting the request using Postman (when I don't include Content-Type in the header because postman takes care of it).
See my code:
Html:
<input type="file" (change)="fileChange($event)" placeholder="Upload file" accept=".pdf,.doc,.docx,.dwg,.jpeg,.jpg">
Service function:
uploadFile(event) {
let fileUploadUrl = this.webApiFileUploadURL;
let fileList: FileList = event.target.files;
if(fileList.length > 0) {
let file: File = fileList[0];
let formData:FormData = new FormData();
formData.append('uploadFile', file, file.name);
let headers = new Headers();
headers.append('Content-Type', 'multipart/form-data');
headers.append('Accept', 'application/json');
let options = new RequestOptions({ headers: headers });
this._http.post(`${this.webApiFileUploadURL}`, formData, options)
.map(res => res.json())
.catch(error => Observable.throw(error))
.subscribe(
data => console.log('success'),
error => console.log(error)
)
}
And the WebApi post request (fails at
if (!Request.Content.IsMimeMultipartContent()) ):
public async Task<HttpResponseMessage> PostFormData()
{
// Check if the request contains multipart/form-data.
if (!Request.Content.IsMimeMultipartContent()) // Fails here
{
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);
}
}

After a thorough research - I've succeeded:
No need to set the content-type header property when posting.
I've removed it from my angular2 http.post request and the
Request.Content.IsMimeMultipartContent() in the web-api post method passed (same as in postman)

If anyone else runs into this "The request entity's media type 'multipart/form-data' is not supported for this resource."
You may need to add this in you webapiconfig
config.Formatters.JsonFormatter.SupportedMediaTypes.Add(new MediaTypeHeaderValue("multipart/form-data"));
Original Credit

After so much reading, my guess is that you need to save your uploaded files asychronously (i just refer to it as JQUERY_D_UPLOAD).
I've created this small ASP.NET C# async task below to get you started.
NOTE: should return a string eg return "This was created by onyangofred#gmail.com";
For more, find me in my turing.com/github/facebook/gmail accounts: (onyangofred)
public async Task<string> SaveFile()
{
for (int i = 0; i < Request.Files.Count; i++)
{
HttpPostedFileBase file = Request.Files[i];
using (var stream = new FileStream(Path.Combine("~/uploads", Guid.NewGuid().ToString() + Path.GetExtension(file.FileName)), FileMode.Create, FileAccess.Write, FileShare.Write, 4096, useAsync: true))
{
await file.InputStream.CopyToAsync(stream);
}
}
}

Related

CKEditor and C# Web API, upload image with simple upload plugin

In my project I use CKEditor WYSWYG package to make HTML content for my website.
There is possible to insert image and send it directly from the package to the server.
Since 2 days I try to figure out how is it possible to catch the sent image from the Angular front-end to the Web API, but still no success.
I use .Net6 and Angular 12 with CKEditor 5.
public async Task<ActionResult<string>> AddPostPhoto(IFormFile photo)
{
try
{
System.Console.WriteLine(Request.ContentType);
var folderDirectory = $"\\Photos\\PostPhotos";
var path = Path.Combine("Photos/PostPhotos", "fileName.jpg");
var memoryStream = new MemoryStream();
await Request.Body.CopyToAsync(memoryStream);
System.Console.WriteLine(Request.HttpContext.Request.ContentLength);
System.Console.WriteLine(Request.Form.Keys);
if (!Directory.Exists(folderDirectory))
{
Directory.CreateDirectory(folderDirectory);
}
await using (var fs = new FileStream(path, FileMode.Create, FileAccess.Write))
{
memoryStream.WriteTo(fs);
}
return Ok(new { Url = path });
}
catch(Exception exception)
{
return BadRequest(exception.Message);
}
}
Finally I could find a working solution.
my-upload-adapter.ts
//ckeditorExComponent class Ends here and MyUploadAdapter class begins here in the same ckeditorEx.ts
export class MyUploadAdapter {
xhr: any;
loader: any;
serverUrl: string;
baseApiUrl: string;
constructor(loader: any, serverUrl: string, baseApiUrl: string) {
// The file loader instance to use during the upload.
this.loader = loader;
this.serverUrl = serverUrl;
this.baseApiUrl = baseApiUrl;
}
// Starts the upload process.
upload() {
return this.loader.file
.then((file: any) => new Promise((resolve, reject) => {
this._initRequest();
this._initListeners(resolve, reject, file);
this._sendRequest(file);
}));
}
// Aborts the upload process.
abort() {
if (this.xhr) {
this.xhr.abort();
}
}
// Initializes the XMLHttpRequest object using the URL passed to the constructor.
_initRequest() {
const xhr = this.xhr = new XMLHttpRequest();
// Note that your request may look different. It is up to you and your editor
// integration to choose the right communication channel. This example uses
// a POST request with JSON as a data structure but your configuration
// could be different.
//Replace below url with your API url
xhr.open('POST', this.baseApiUrl + 'Tutorial/add-post-photo', true);
xhr.responseType = 'json';
}
// Initializes XMLHttpRequest listeners.
_initListeners(resolve: any, reject: any, file: any) {
const xhr = this.xhr;
const loader = this.loader;
const genericErrorText = `Couldn't upload file: ${file.name}.`;
xhr.addEventListener('error', () => reject(genericErrorText));
xhr.addEventListener('abort', () => reject());
xhr.addEventListener('load', () => {
const response = xhr.response;
// This example assumes the XHR server's "response" object will come with
// an "error" which has its own "message" that can be passed to reject()
// in the upload promise.
//
// Your integration may handle upload errors in a different way so make sure
// it is done properly. The reject() function must be called when the upload fails.
if (!response || response.error) {
return reject(response && response.error ? response.error.message : genericErrorText);
}
// If the upload is successful, resolve the upload promise with an object containing
// at least the "default" URL, pointing to the image on the server.
// This URL will be used to display the image in the content. Learn more in the
// UploadAdapter#upload documentation.
resolve({
default: this.serverUrl + response.url
});
});
// Upload progress when it is supported. The file loader has the #uploadTotal and #uploaded
// properties which are used e.g. to display the upload progress bar in the editor
// user interface.
if (xhr.upload) {
xhr.upload.addEventListener('progress', (evt: any) => {
if (evt.lengthComputable) {
loader.uploadTotal = evt.total;
loader.uploaded = evt.loaded;
}
});
}
}
// Prepares the data and sends the request.
_sendRequest(file: any) {
// Prepare the form data.
const data = new FormData();
data.append('upload', file);
// Important note: This is the right place to implement security mechanisms
// like authentication and CSRF protection. For instance, you can use
// XMLHttpRequest.setRequestHeader() to set the request headers containing
// the CSRF token generated earlier by your application.
// Send the request.
this.xhr.send(data);
}
}
In the Angular component
onReady($event: any) {
$event.plugins.get('FileRepository').createUploadAdapter = (loader: any) => {
return new MyUploadAdapter(loader, this.serverUrl, this.apiUrl);
};
}
The C# Web API controller
[HttpPost("add-post-photo")]
public async Task<ActionResult<string>> AddPostPhoto(IFormFile upload)
{
try
{
FileInfo fileInfo = new FileInfo(upload.FileName);
System.Console.WriteLine(upload.FileName);
var folderDirectory = $"\\Photos\\PostPhotos";
var path = Path.Combine("Photos\\PostPhotos", upload.FileName);
var memoryStream = new MemoryStream();
await upload.OpenReadStream().CopyToAsync(memoryStream);
if (!Directory.Exists(folderDirectory))
{
Directory.CreateDirectory(folderDirectory);
}
await using (var fs = new FileStream(path, FileMode.Create, FileAccess.Write))
{
memoryStream.WriteTo(fs);
}
return Ok(new { Url = path });
}
catch(Exception exception)
{
return BadRequest(exception.Message);
}
}
It is important to have the parameter upload, otherwise the find the back-end endpoint

Send file from Android Kotlin to C# using POST

We have two applications: A C# REST-API, and a Kotlin Android application, we are using Google Platform Cloud Bucket to host the images.
A picture will be uploaded on the Android application, but the C# REST-API needs to upload it to the Google Cloud Platform.
This is the working C# code to upload a file to the Google Cloud Buckets:
[HttpPost]
[Route("upload")]
public IActionResult Upload()
{
var storageClient = StorageClient.Create(google_credentials);
string fileToUpload ="/Users/niel/Downloads/new_cat.jpg";
using (var fileStream = new FileStream(fileToUpload, FileMode.Open,
FileAccess.Read, FileShare.Read))
{
storageClient.UploadObject("test_storage_fotos", "new_cat", "image/jpeg", fileStream);
}
Console.WriteLine("uploaded the file successfully");
return Ok();
}
Now I need to replace fileToUpload with the content from a POST-request. Is there a way to do this? Picture from Android app > C# API > Google Buckets? The link from the C# API to Google Buckets is already working.
Is there a way in Kotlin to somehow get the byte-string of an image, post it to my C# API who takes the content and puts it in a FileStream? I than can upload the FileStream using storageClient.UploadObject? Is this a possibility?
Thanks!
Yes, you can definitely do this. Just send the file over to the server via http protocol with multipart/form-data content type.
In kotlin you can use ktor or any other http library to do that.
For ktor you'll need to add an implementation dependency
implementation "io.ktor:ktor-client-android:1.5.4"
And you might also need to add additional permission in AndroidManifest.xml
<uses-permission android:name="android.permission.INTERNET" />
Then you can send a file with this snippet. Notice that imageUri is a content uri, for file uri the code would be a bit different
private fun getFileName(resolver: ContentResolver, uri: Uri): String {
val returnCursor: Cursor = resolver.query(uri, null, null, null, null)!!
val nameIndex: Int = returnCursor.getColumnIndex(OpenableColumns.DISPLAY_NAME)
returnCursor.moveToFirst()
val name: String = returnCursor.getString(nameIndex)
returnCursor.close()
return name
}
suspend fun postAndImage(imageUri: Uri, uploadEndPoint: String) {
val client = HttpClient(Android)
val cr = applicationContext.contentResolver
if(cr.getType(imageUri) == null) {
//process error
return
}
val stream = cr.openInputStream(imageUri)
if(stream == null) {
//process error
return
}
val response: HttpResponse = client.submitFormWithBinaryData(
url = uploadEndPoint,
formData = formData {
append("image", InputProvider { stream.asInput() }, Headers.build {
append(HttpHeaders.ContentType, cr.getType(imageUri)!!)
append(HttpHeaders.ContentDisposition, "filename=${getFileName(cr, imageUri)}")
})
}
)
stream.close()
//process response
}
And you'll need to modify you upload function slightly
[HttpPost]
[Route("upload")]
//the name of the argument must match the key that you pass in "append" function
public async Task<IActionResult> Post(IFormFile image)
{
var storageClient = StorageClient.Create(google_credentials);
using (var stream = image.OpenReadStream())
{
//it's also possible to get original file name from file name property
var fileName = Guid.NewGuid() + "." + Path.GetExtension(image.FileName);
//assuming bucket is already created
var storageObject = await storageClient
.UploadObjectAsync("test_storage_fotos", fileName, "image/jpeg", stream);
//save information about a storage object in database
}
return Ok();
}

How to save file using ng-file-upload in ASP .NET Web API 2 application?

i try save file to server, i'm using the ng-file-upload directive, i added the next html - code:
<button class="button" ngf-select ng-model="fileCover" name="fileCover" ngf-pattern="'image/*'"
ngf-accept="'image/*'" ngf-max-size="20MB" ngf-min-height="100">Select</button>
<button type="submit" ng-click="submitUpload(fileCover)">submit</button>
and my angularjs-code:
$scope.submitUpload = function (fileCover) {
console.log(fileCover);
Upload.upload({
url: '/api/upload',
data: { file: fileCover }
});
};
And i have a empty controller:
[Route("upload")]
[HttpPost]
public void Upload ( )
{
}
Tell me please, how i can save files at server side ?Thanks for your answers!
I have a solution using an older version of ng-file-upload (angular-file-upload), and my WebApi method that received the file looks like this:
[HttpPost]
public async Task<HttpResponseMessage> Upload() {
try {
if (!Request.Content.IsMimeMultipartContent()) {
Request.CreateResponse(HttpStatusCode.UnsupportedMediaType);
}
var provider = GetMultipartProvider();
var result = await Request.Content.ReadAsMultipartAsync(provider);
// On upload, files are given a generic name like "BodyPart_26d6abe1-3ae1-416a-9429-b35f15e6e5d5"
// so this is how you can get the original file name
var originalFileName = GetDeserializedFileName(result.FileData.First());
// uploadedFileInfo object will give you some additional stuff like file length,
// creation time, directory name, a few filesystem methods etc..
var uploadedFileInfo = new FileInfo(result.FileData.First().LocalFileName);
// Create full path for where to move the uploaded file
string targetFile = Path.Combine(uploadedFileInfo.DirectoryName, originalFileName);
// If the file in the full path exists, delete it first otherwise FileInfo.MoveTo() will throw exception
if (File.Exists(targetFile))
File.Delete(targetFile);
}
// Move the uploaded file to the target folder
uploadedFileInfo.MoveTo(targetFile);
// targetFile now contains the uploaded file
// Through the request response you can return an object to the Angular controller
// You will be able to access this in the .success callback through its data attribute
// If you want to send something to the .error callback, use the HttpStatusCode.BadRequest instead
return new HttpResponseMessage(HttpStatusCode.OK);
} catch (Exception ex) {
return new HttpResponseMessage(HttpStatusCode.InternalServerError) { Content = new ObjectContent(ex.GetType(), ex, new JsonMediaTypeFormatter()) };
}
}
private MultipartFormDataStreamProvider GetMultipartProvider() {
var uploadFolder = #"C:\Temp"
if (Directory.Exists(uploadFolder) == false) Directory.CreateDirectory(uploadFolder);
return new MultipartFormDataStreamProvider(uploadFolder);
}
private string GetDeserializedFileName(MultipartFileData fileData) {
var fileName = GetFileName(fileData);
return JsonConvert.DeserializeObject(fileName).ToString();
}
private string GetFileName(MultipartFileData fileData) {
return fileData.Headers.ContentDisposition.FileName;
}
Hopefully the server side functionality hasn't changed much in the versions between what I'm using and the one you are using.

WEB Api upload file and model

How can i upload file and model parameters in mvc WEB API 2.
I have following code, which works just fine, if i remove model from the action, but with the model, I am receiving following error.
"message": "The request entity's media type 'multipart/form-data' is
not supported for this resource.", "exception_message": "No
MediaTypeFormatter is available to read an object of type
'CreateTicketDTO' from content with media type
'multipart/form-data'.",
[HttpPost]
[Route("api/support/tickets/")]
public async Task<HttpResponseMessage> Insert(CreateTicketDTO dto)
{
if(dto == null)
return Request.CreateResponse(HttpStatusCode.BadRequest, "Please supply required parameters");
var provider = new MultipartMemoryStreamProvider();
var a = await Request.Content.ReadAsMultipartAsync(provider);
foreach (var file in provider.Contents)
{
var filename = file.Headers.ContentDisposition.FileName.Trim('\"');
var buffer = await file.ReadAsByteArrayAsync();
//Do whatever you want with filename and its binaray data.
}
using (_ticketService)
{
var ticket = await _ticketService.CreateNewTicket(dto);
return Request.CreateResponse(HttpStatusCode.OK, ticket);
}
}
I am creating a post request in Postman.

ASP .Net Web API RC: Multipart file-upload to Memorystream

I'm trying to save (an) uploaded file(s) to a database/memorystream, but I can't figure it out.
All I have right now is this:
public Task<HttpResponseMessage> AnswerQuestion()
{
if (!Request.Content.IsMimeMultipartContent())
{
throw new HttpResponseException(HttpStatusCode.UnsupportedMediaType);
}
var root = HttpContext.Current.Server.MapPath("~/App_Data");
var provider = new MultipartFormDataStreamProvider(root);
var task = Request.Content.ReadAsMultipartAsync(provider).
ContinueWith<HttpResponseMessage>(t =>
{
if (t.IsFaulted || t.IsCanceled)
{
Request.CreateErrorResponse(HttpStatusCode.InternalServerError, t.Exception);
}
foreach (var file in provider.FileData)
{
Trace.WriteLine(file.Headers.ContentDisposition.FileName);
Trace.WriteLine("Server file path: " + file.LocalFileName);
}
return Request.CreateResponse(HttpStatusCode.OK);
});
return task;
}
But of course this only saves the file to a specific location. I think I have to work with a custom class derived from MediaTypeFormatter to save it to a MemoryStream, but I don't see how to do it.
Please help. Thanks in advance!
Multipart content can be read into any of the concrete implementations of the abstract MultipartStreamProvider class - see http://aspnetwebstack.codeplex.com/SourceControl/changeset/view/8fda60945d49#src%2fSystem.Net.Http.Formatting%2fMultipartStreamProvider.cs.
These are:
- MultipartMemoryStreamProvider
- MultipartFileStreamProvider
- MultipartFormDataStreamProvider
- MultipartRelatedStreamProvider
In your case:
if (Request.Content.IsMimeMultipartContent())
{
var streamProvider = new MultipartMemoryStreamProvider();
var task = Request.Content.ReadAsMultipartAsync(streamProvider).ContinueWith(t =>
{
foreach (var item in streamProvider.Contents)
{
//do something
}
});
}
You can use MultipartMemoryStreamProvider for your scenario.
[Updated] Noticed that you are using RC, i think MultipartMemoryStreamProvider was added post-RC and is currently in RTM.

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