Develop Reference

Flutter VideoPlayerController network request from web api

I am making a flutter app and using the VideoPlayerController library package and requesting video content via network:
VideoPlayerController newController = VideoPlayerController.network(
"http://192.168.1.1:9999/S3/get-object/name-of-video.mp4");
My Web API Backend is .NET Core 3 and the controller endpoint is this:
[AllowAnonymous]
[HttpGet("get-object/{url}")]
public async Task<FileStreamResult> GetObject(string url)
{
// Seperate out only the filename
string[] res = url.Split(new string[] { "%2F" }, StringSplitOptions.None);
string fileName = res.LastOrDefault();
Stream imageStream = await S3Helper.ReadObjectData(_appSettings, fileName);
Response.Headers.Add("Content-Disposition", new ContentDisposition
{
FileName = fileName,
Inline = true // false = prompt the user for downloading; true = browser to try to show the file inline
}.ToString());
if (fileName.Contains(".jpg") || fileName.Contains(".jpeg"))
{
return File(imageStream, "image/jpeg");
}
else if (fileName.Contains(".png"))
{
return File(imageStream, "image/png");
}
else if (fileName.Contains(".mp4"))
{
return File(imageStream, new MediaTypeHeaderValue("video/mp4").MediaType, true);
}
else
{
return null;
}
}
However, when I create a widget that uses a Network image, it actually works. I'm not sure what the difference is.
CachedNetworkImage(
imageUrl: "http://192.168.1.1:9999/S3/get-object/name-of-image.jpg",
placeholder: (context, url) =>
CircularProgressIndicator(),
errorWidget: (context, url, error) =>
Icon(Icons.error),
fit: BoxFit.contain,
),
The .Net Core Backend has the video coming via an http get request as an inline video, similar to this one:
https://flutter.github.io/assets-for-api-docs/assets/videos/butterfly.mp4
The error I get from my flutter app shows up like this:
Source error. E/ExoPlayerImplInternal(24687): com.google.android.exoplayer2.upstream.HttpDataSource$HttpDataSourceException: Unable to connect to http://192.168.1.1:9999/S3/get-object/name-of-video.mp4

I don't know about ios. But android doesn't allow http://. You need to provide a link starting https://.
To allow the http:// or others
add this line on androids AndroidManifest.xml.
Location android\app\src\main\AndroidManifest.xml
android:usesCleartextTraffic="true"
This should look like this:

How to create downloadable file link for the file to download in ASP.net core

Previously I was sending file as Byte array from ASP.net core 2.0 and in Angular 4 application I am calling below function to download the file
function (response) { // Here response is byte array
var url= window.URL.createObjectURL(res);
var link = document.createElement("a");
link.setAttribute("href", url);
link.setAttribute("download", this.zipLocation + ".zip");
link.style.display = "none";
document.body.appendChild(link);
link.click();
document.body.removeChild(link);
}
But now I want to send the file path from the server like below
https://websiteaddress/file/path/to/download.ext
So in Angular 5, I can directly attach link to href attribute of anchor tag and will make automatic click on that. So I don't need to Convert byte array to url
Here the issue is I don't know how to create that downloadable file path using ASP.net core and send it to frontend
And also I want to know, which approach is better, whether sending Byte array or Sending the direct link? Is there any performance issue with any of the two?

If you are using api response as file data
add responseType: 'arraybuffer' in request header.
Try something like this:
HTML:
<a (click)="downLoad()">Click To Download</a>
TS:
downLoad(){
this.fileService.getFileFromServer(fileId.toString()).subscribe(respData => {
this.downLoadFile(respData, this.type);
}, error => {
});
}
/**
* Method is use to download file.
* #param data - Array Buffer data
* #param type - type of the document.
*/
downLoadFile(data: any, type: string) {
var blob = new Blob([data], { type: type.toString() });
var url = window.URL.createObjectURL(blob);
var pwa = window.open(url);
if (!pwa || pwa.closed || typeof pwa.closed == 'undefined') {
console.log('Please disable your Pop-up blocker and try again');
}
}
file-service.ts:
getFileFromServer(id){
return this.http.get(url, {responseType: 'arraybuffer',headers:headers});
}

your question make confuse about angular frontend and backend
frontend you can use mvc
<a asp-controller="Controller"
asp-action="Download"
asp-route-id="#Model.FileName">Download #Model.FileName</a>
or using angular
Download
<a [href]="ControllerRoute+'/Download?name='+fileName" download>Download {{fileName}}</a>
Ok maybe your problem is your action (in controller) doesnt server a file
you need return a HttpResponse with a MediaType, this is just a example, dont forget best practices on your code
[HttpGet]
public HttpResponseMessage GetDownloadableFIle(string name)
{
try
{
var result = new HttpResponseMessage(HttpStatusCode.OK);
var filePath = $"{MyRootPath}/{name}";
var bytes = File.ReadAllBytes(filePath );
result.Content = new ByteArrayContent(bytes);
var mediaType = "application/octet-stream";
result.Content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue(mediaType);
return result;
}
catch (Exception ex)
{
throw new HttpResponseException(Request.CreateResponse(HttpStatusCode.InternalServerError, ex.ToString()));
}
}

Saving uploaded file from user with bot framework c#

I am currently trying to allow a user to upload a file to the bot during a dialog flow. From there the bot will take the file and upload it to blob storage. When the file comes in the content property is null, however the content url, name, and type all have the correct values.
public virtual async Task StackTraceGathered(IDialogContext context, IAwaitable<IMessageActivity> argument)
{
var message = await argument;
FileName = message.Attachments[0].Name;
HttpPostedFileBase file = (HttpPostedFileBase)message.Attachments[0].Content;
string filePath = HttpContext.Current.Server.MapPath("~/Files/" + file.FileName);
file.SaveAs(filePath);
if (message.Attachments != null && message.Attachments.Any())
{
var attachment = message.Attachments.First();
using (HttpClient httpClient = new HttpClient())
{
// Skype & MS Teams attachment URLs are secured by a JwtToken, so we need to pass the token from our bot.
if ((message.ChannelId.Equals("skype", StringComparison.InvariantCultureIgnoreCase) || message.ChannelId.Equals("msteams", StringComparison.InvariantCultureIgnoreCase))
&& new Uri(attachment.ContentUrl).Host.EndsWith("skype.com"))
{
var token = await new MicrosoftAppCredentials().GetTokenAsync();
httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token);
}
var responseMessage = await httpClient.GetAsync(attachment.ContentUrl);
var contentLenghtBytes = responseMessage.Content.Headers.ContentLength;
await context.PostAsync($"Attachment of {attachment.ContentType} type and size of {contentLenghtBytes} bytes received.");
}
}
else
{
await context.PostAsync("Hi there! I'm a bot created to show you how I can receive message attachments, but no attachment was sent to me. Please, try again sending a new message including an attachment.");
}
PromptDialog.Text(context, ProblemStartDuration, "How long has this been an issue? (Provide answer in days, if issue has been occurring for less than one day put 1).");
context.Wait(this.StackTraceGathered);
}

I don't see the issue, but I guess you are expecting the Content property to have something. It won't but you just need the Url. Two alternatives:
Download the attachment in the bot (as the code you are using in the question) and upload to blob storage
Try to upload the attachment directly from the Url using something like StartCopyFromBlob (check this)

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.

unable to configure Web API for content type multipart

I am working on Web APIs - Web API 2. My basic need is to create an API to update the profile of the user. In this, the ios and android will send me the request in multipart/form-data. They will send me a few parameters with an image. But whenever I try to create the API, my model comes to be null every time.
I have also added this line in WebApiConfig:
config.Formatters.JsonFormatter.SupportedMediaTypes
.Add(new MediaTypeHeaderValue("multipart/form-data"));
This is my class:
public class UpdateProfileModel
{
public HttpPostedFileBase ProfileImage { get; set; }
public string Name { get; set; }
}
This is my controller:
[Route("api/Account/UpdateProfile")]
[HttpPost]
public HttpResponseMessage UpdateProfile(UpdateProfileModel model)
{
}
I am even not getting parameter values in my Model. Am I doing something wrong?
None of the answers related to this were helpful for me. It's about 3rd day and I have tried almost everything and every method. but I am unable to achieve it.
Although I can use this but this as shown below but this doesn't seem to be a good approach. so I am avoiding it.
var httpRequest = HttpContext.Current.Request;
if (httpRequest.Form["ParameterName"] != null)
{
var parameterName = httpRequest.Form["ParameterName"];
}
and for files I can do this:
if (httpRequest.Files.Count > 0)
{
//I can access my files here and save them
}
Please help if you have any good approach for it Or Please explain to me why I am unable to get these values in the Model.
Thanks a lot in Advance

The answer provided by JPgrassi is what you would be doing to have MultiPart data. I think there are few more things that needs to be added, so I thought of writing my own answer.
MultiPart form data, as the name suggest, is not single type of data, but specifies that the form will be sent as a MultiPart MIME message, so you cannot have predefined formatter to read all the contents. You need to use ReadAsync function to read byte stream and get your different types of data, identify them and de-serialize them.
There are two ways to read the contents. First one is to read and keep everything in memory and the second way is to use a provider that will stream all the file contents into some randomly name files(with GUID) and providing handle in form of local path to access file (The example provided by jpgrassi is doing the second).
First Method: Keeping everything in-memory
//Async because this is asynchronous process and would read stream data in a buffer.
//If you don't make this async, you would be only reading a few KBs (buffer size)
//and you wont be able to know why it is not working
public async Task<HttpResponseMessage> Post()
{
if (!request.Content.IsMimeMultipartContent()) return null;
Dictionary<string, object> extractedMediaContents = new Dictionary<string, object>();
//Here I am going with assumption that I am sending data in two parts,
//JSON object, which will come to me as string and a file. You need to customize this in the way you want it to.
extractedMediaContents.Add(BASE64_FILE_CONTENTS, null);
extractedMediaContents.Add(SERIALIZED_JSON_CONTENTS, null);
request.Content.ReadAsMultipartAsync()
.ContinueWith(multiPart =>
{
if (multiPart.IsFaulted || multiPart.IsCanceled)
{
Request.CreateErrorResponse(HttpStatusCode.InternalServerError, multiPart.Exception);
}
foreach (var part in multiPart.Result.Contents)
{
using (var stream = part.ReadAsStreamAsync())
{
stream.Wait();
Stream requestStream = stream.Result;
using (var memoryStream = new MemoryStream())
{
requestStream.CopyTo(memoryStream);
//filename attribute is identifier for file vs other contents.
if (part.Headers.ToString().IndexOf("filename") > -1)
{
extractedMediaContents[BASE64_FILE_CONTENTS] = memoryStream.ToArray();
}
else
{
string jsonString = System.Text.Encoding.ASCII.GetString(memoryStream.ToArray());
//If you need just string, this is enough, otherwise you need to de-serialize based on the content type.
//Each content is identified by name in content headers.
extractedMediaContents[SERIALIZED_JSON_CONTENTS] = jsonString;
}
}
}
}
}).Wait();
//extractedMediaContents; This now has the contents of Request in-memory.
}
Second Method: Using a provider (as given by jpgrassi)
Point to note, this is only filename. If you want process file or store at different location, you need to stream read the file again.
public async Task<HttpResponseMessage> Post()
{
HttpResponseMessage response;
//Check if request is MultiPart
if (!Request.Content.IsMimeMultipartContent())
{
throw new HttpResponseException(HttpStatusCode.UnsupportedMediaType);
}
//This specifies local path on server where file will be created
string root = HttpContext.Current.Server.MapPath("~/App_Data");
var provider = new MultipartFormDataStreamProvider(root);
//This write the file in your App_Data with a random name
await Request.Content.ReadAsMultipartAsync(provider);
foreach (MultipartFileData file in provider.FileData)
{
//Here you can get the full file path on the server
//and other data regarding the file
//Point to note, this is only filename. If you want to keep / process file, you need to stream read the file again.
tempFileName = file.LocalFileName;
}
// You values are inside FormData. You can access them in this way
foreach (var key in provider.FormData.AllKeys)
{
foreach (var val in provider.FormData.GetValues(key))
{
Trace.WriteLine(string.Format("{0}: {1}", key, val));
}
}
//Or directly (not safe)
string name = provider.FormData.GetValues("name").FirstOrDefault();
response = Request.CreateResponse(HttpStatusCode.Ok);
return response;
}

By default there is not a media type formatter built into the api that can handle multipart/form-data and perform model binding. The built in media type formatters are :
JsonMediaTypeFormatter: application/json, text/json
XmlMediaTypeFormatter: application/xml, text/xml
FormUrlEncodedMediaTypeFormatter: application/x-www-form-urlencoded
JQueryMvcFormUrlEncodedFormatter: application/x-www-form-urlencoded
This is the reason why most answers involve taking over responsibility to read the data directly from the request inside the controller. However, the Web API 2 formatter collection is meant to be a starting point for developers and not meant to be the solution for all implementations. There are other solutions that have been created to create a MediaFormatter that will handle multipart form data. Once a MediaTypeFormatter class has been created it can be re-used across multiple implementations of Web API.
How create a MultipartFormFormatter for ASP.NET 4.5 Web API
You can download and build the full implementation of the web api 2 source code and see that the default implementations of media formatters do not natively process multi part data.
https://aspnetwebstack.codeplex.com/

You can't have parameters like that in your controller because there's no built-in media type formatter that handles Multipart/Formdata. Unless you create your own formatter, you can access the file and optional fields accessing via a MultipartFormDataStreamProvider :
Post Method
public async Task<HttpResponseMessage> Post()
{
HttpResponseMessage response;
//Check if request is MultiPart
if (!Request.Content.IsMimeMultipartContent())
{
throw new HttpResponseException(HttpStatusCode.UnsupportedMediaType);
}
string root = HttpContext.Current.Server.MapPath("~/App_Data");
var provider = new MultipartFormDataStreamProvider(root);
//This write the file in your App_Data with a random name
await Request.Content.ReadAsMultipartAsync(provider);
foreach (MultipartFileData file in provider.FileData)
{
//Here you can get the full file path on the server
//and other data regarding the file
tempFileName = file.LocalFileName;
}
// You values are inside FormData. You can access them in this way
foreach (var key in provider.FormData.AllKeys)
{
foreach (var val in provider.FormData.GetValues(key))
{
Trace.WriteLine(string.Format("{0}: {1}", key, val));
}
}
//Or directly (not safe)
string name = provider.FormData.GetValues("name").FirstOrDefault();
response = Request.CreateResponse(HttpStatusCode.Ok);
return response;
}
Here's a more detailed list of examples:
Sending HTML Form Data in ASP.NET Web API: File Upload and Multipart MIME

Not so sure this would be helpful in your case , have a look
mvc upload file with model - second parameter posted file is null
and
ASP.Net MVC - Read File from HttpPostedFileBase without save

So, what worked for me is -
[Route("api/Account/UpdateProfile")]
[HttpPost]
public Task<HttpResponseMessage> UpdateProfile(/* UpdateProfileModel model */)
{
string root = HttpContext.Current.Server.MapPath("~/App_Data");
var provider = new MultipartFormDataStreamProvider(root);
await Request.Content.ReadAsMultipartAsync(provider);
foreach (MultipartFileData file in provider.FileData)
{
}
}
Also -
config.Formatters.JsonFormatter.SupportedMediaTypes.Add(new MediaTypeHeaderValue("multipart/form-data"));
isn't required.
I guess the multipart/form-data is internally handled somewhere after the form is submitted.
Very clearly described here -
http://www.asp.net/web-api/overview/advanced/sending-html-form-data-part-2