how to download file from other server using mvc asp.net - c#

How can i download file from other server and save it at my own using mvc asp.net with c#?

I am only able to read your title, nevertheless:
WebClient client = new WebClient();
client.DownloadFile("http://your-address.com/FileToDonwload.ext", "c:\PathToTheFileToCreate");
should do what you wanted.

i'd use the System.Web.Mvc.FilePathResult along the following lines:
// most controller logic ommitted
public ActionResult DownloadFile(int fileID)
{
// in this example fileID would map to a file location in the database
var item = _repository.GetByKey(fileID);
// item.DocType would equal "application/msword" / "image/jpeg" etc, etc;
return File(item.DocumentLocation, item.DocType);
}
[edit] - ooops, just realised that this will only work on same server/domain, but have left for reference

Related

Post large files to REST Endpoint c# .net core

I need to post large files in chunks to an external API. The files type is an MP4 that I have downloaded to my local system and they can be up to 4 gig in size. I need to chunk this data and send it out. Everything I looked at deals with the posting from a Web front end (Angular, JS, etc) and handling the chunked data on the controller. I need to take the file that I have saved local and chunk it up and send it off to an existing API that is expecting chunked data.
Thanks
I think these 2 links can help you to achieve what you need, normally the IFormFile has restrictions for big files, in this case, you need to stream it.
This is from MVC 2 and will help you to understand the HttpPostedFileBase approach
Same approach but wrapping it into a class
Asp.net core 2.2 has the correct example on the documentation in case you want to upload bigger files : See this section
The idea behind is to stream the content, for that, you need to disable the bindings that Asp.net core has and start streaming the content that was posted/uploaded.
After you receive that information, then you use the FormValueProvider to rebind all the key/value you received from the client.
Because you are using multipart content type, you need to be aware that all the content will not come in the same order, maybe you receive the file, later other parameters or vice-versa.
[HttpPost(Name = "CreateDocumentForApplication")]
[DisableFormValueModelBinding]
public async Task<IActionResult> CreateDocumentForApplication(Guid tenantId, Guid applicationId, DocumentForCreationDto docForCreationDto, [FromHeader(Name = "Accept")] string mediaType)
{
//use here the code of the asp.net core documentation on the Upload method to read the file and save it, also get your model correctly after the binding
}
you can notice that I am passing more parameters as part of the post like DocumentForCreationDto, but the approach is the same(disable the binding)
public class DocumentForCreationDto : IDto
{
//public string CreatedBy { get; set; }
public string DocumentName { get; set; }
public string MimeType { get; set; }
public ICollection<DocumentTagInfoForCreationDto> Tags { get; set; }
}
If you want to use the postman, see how I am passing the paremeters:
If you want to upload it via code here is the pseudocode:
void Upload()
{
var content = new MultipartFormDataContent();
// Add the file
var fileContent = new ByteArrayContent(file);
fileContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("form-data")
{
FileName = fileName,
FileNameStar = "file"
};
content.Add(fileContent);
//this is the way to add more content to the post
content.Add(new StringContent(documentUploadDto.DocumentName), "DocumentName");
var url = "myapi.com/api/documents";
HttpResponseMessage response = null;
try
{
response = await _httpClient.PostAsync(url, content);
}
catch (Exception e)
{
Console.WriteLine(e);
}
}
Hope this helps

Download File through headers from different server

I have PDF file placed on different (FILE-Server) server machine, and the IIS machine on which my MVC application is hosted have rights to that File-Server. From IIS machine i can access the file through following URI:
file://file-server/data-folder/pdf/19450205.pdf
I want to enable my MVC app's users to download their respective files by clicking on download link or button. So probably i would have to write some Action for that link/button.
I tried to use File return type for my Action method in following way:
public ActionResult FileDownload()
{
string filePth = #"file://file-server/data-folder/pdf/19450205.pdf";
return File(filePth , "application/pdf");
}
but the above code gives exception of URI not supported.
I also tried to use FileStream to read bytes inside array return that bytes towards download, but FileStream also gives error of not proper "Virtual Path" as the file is not placed inside virtual path, its on separate server.
public ActionResult Download()
{
var document = = #"file://file-server/data-folder/pdf/19450205.pdf";
var cd = new System.Net.Mime.ContentDisposition
{
// for example foo.bak
FileName = document.FileName,
// always prompt the user for downloading, set to true if you want
// the browser to try to show the file inline
Inline = false,
};
Response.AppendHeader("Content-Disposition", cd.ToString());
return File(document.Data, document.ContentType);
}
Thanks for the replies, but both suggestion did not work.
as file needs to be accessed over URI, using FileInfo gives error: URI formats are not supported.
I managed to get this done through following mechanism:
public ActionResult FaxFileDownload()
{
string filePth = #"file://file-server/data-folder/pdf/19450205.pdf";
WebClient wc = new WebClient();
Stream s = wc.OpenRead(filePth);
return File(s, "application/pdf");
}
Thanks to All.

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

Can I upload a file and a model to an MVC 4 action at the same time from a Winforms app?

I am required to integrate a signature pad into an intranet (MVC4) application allowing people to apply electronic signatures to system generated documents. Unfortunately, the signature pad I've been given only has a COM/ActiveX API, so I've written a short Windows Forms application that will allow the user to capture the signature and upload it to the server. When it is uploaded, I need the MVC4 action to associate the signature image with a specified document entity sent by the Windows Forms request. So, say I have this model:
public class DocumentToSign {
public int DocumentId { get; set; }
public int DocumentTypeId { get; set; }
}
Then I have this action to receive the uploaded image:
[HttpPost]
public ActionResult UploadSignature(DocumentToSign doc, HttpPostedFileBase signature)
{
//do stuff and catch errors to report back to winforms app
return Json(new {Success = true, Error = string.Empty});
}
Then, the code to upload the image:
var doc = new DocumentToSign{ DocumentId = _theId, DocumentTypeId = _theType };
var fileName = SaveTheSignature();
var url = GetTheUrl();
using(var request = new WebClient())
{
request.Headers.Add("enctype", "multipart/form-data");
foreach(var prop in doc.GetType().GetProperties())
{
request.QueryString.Add(prop.Name, Convert.ToString(prop.GetValue(doc, null)));
}
var responseBytes = request.UploadFile(url, fileName);
//deserialize resulting Json, etc.
}
The model binder seems to pick up the DocumentToSign class without any problems, but the HttpPostedFileBase is always null. I know that I need to somehow tell the model binder that the uploaded image is the signature parameter in the action, but I can't figure out how to do it. I tried using UploadValues with a NameValueCollection, but NameValueCollection only allows the value to be a string, so the image (even as a byte[]) can't be part of that.
Is it possible to upload a file as well as a model to the same action from outside of the actual MVC4 application? Should I be using something other than HttpPostedFileBase? Other than the WebClient? I am at a loss.
var responseBytes = request.UploadFile(url, fileName); is not sending your file in the format your controller expect.
HttpPostedFileBase works with multipart/form-data POST request. But WebClient.UploadFile is not sending a multipart request, it sends file content as a body of request with no other information.
You can save the file by calling Request.SaveAs(filename, false);
or you have to change the way you are sending the file. But I don't think WebClient support sending multipart requests.

Open external PDF file in asp.net MVC 2

I know how to open an internal pdf file :
public ActionResult GetPDF( string filename )
{
return File( filename, "application/pdf", Server.HtmlEncode( filename ) );
}
question is, how to open a PDF file from an other/external website, e.g. http://example.com/mypdffile.pdf
You don't really need a controller action to do this. You could simply:
Open mypdffile.pdf
Of course if you want to hide this address from the user you could use a WebClient to fetch it on the server:
public ActionResult GetPDF()
{
using (var client = new WebClient())
{
var buffer = client.DownloadData("http://www.blabla.com/mypdffile.pdf");
return File(buffer, "application/pdf", "mypdffile.pdf");
}
}
And in your view:
<%= Html.ActionLink("Download PDF", "GetPDF") %>
You will need it locally anyway to do any processing so, you can download it to local folder and then show it. use WebClient or HttpRequest/HttpResponse objects to do the downloading

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