I am trying to generate pdf file using c# web api using the following code :
i have tried to change in the web.config but it didn't help.
[HttpGet]
public HttpResponseMessage Generate()
{
var stream = new MemoryStream();
// processing the stream.
var result = new HttpResponseMessage(HttpStatusCode.OK)
{
Content = new ByteArrayContent(stream.ToArray())
};
result.Content.Headers.ContentDisposition = new
System.Net.Http.Headers.ContentDispositionHeaderValue("attachment")
{
FileName = "CertificationCard.pdf"
};
result.Content.Headers.ContentType =
new MediaTypeHeaderValue("application/octet-stream");
return result;
}
I expected download pdf directly to my local disk but non worked.
Related
I am using ASP.NET WEB API to upload image to server. But when i upload the source code of my web api to gearhost.com and make a post request. I am unable to post the image. This is my web api controller code:
[Route("upload")]
[HttpPost]
public async Task<string> Upload()
{
var ctx = HttpContext.Current;
var root = ctx.Server.MapPath("/uploads/");
var provider = new MultipartFormDataStreamProvider(root);
try
{
await Request.Content
.ReadAsMultipartAsync(provider);
foreach (var file in provider.FileData)
{
var name = file.Headers
.ContentDisposition
.FileName;
// remove double quotes from string.
name = name.Trim('"');
var localFileName = file.LocalFileName;
var filePath = Path.Combine(root, "files", name);
// File.Move(localFileName, filePath);
// SaveFilePathSQLServerADO(localFileName, filePath);
// SaveFileBinarySQLServerADO(localFileName, name);
// SaveFilePathSQLServerEF(localFileName, filePath);
SaveFileBinarySQLServerEF(localFileName, name, filePath);
if (File.Exists(localFileName))
File.Delete(localFileName);
}
}
catch
{
return "Error";
}
return "File uploaded successfully!";
}
public void SaveFileBinarySQLServerEF(string localFile, string fileName, string filePath)
{
// 1) Get file binary
byte[] fileBytes;
using (var fs = new FileStream(localFile, FileMode.Open, FileAccess.Read))
{
fileBytes = new byte[fs.Length];
fs.Read(fileBytes, 0, Convert.ToInt32(fs.Length));
}
// 2) Create a Files object
var file = new tblimage()
{
Data = fileBytes,
Names = fileName,
ContentType = filePath
};
// 3) Add and save it in database
using (var ctx = new coachEntities())
{
ctx.tblimages.Add(file);
ctx.SaveChanges();
}
}
Here is the successful call from localhost:
Image posted through localhost
However when deployed the same code and make request through postman then I get this error:
Image posted through live server
Maybe, "uploads" doesn't have write permission
Check the permission in your uploads folder.
Go to properties-- security
Give the read write permission.
Though it is not good idea to return the exception details in live code. As you are not maintaining log. For testing, Please return the exception details. Also, how are you getting the response like "unable to upload, try again" because it is not there in your code
Call Rest service
Rest service returns byte[] representation of image/audio/video
convert into byte[] to image and show in content page in xamarin
First of all, you can create a function that simply makes an API request and obtains the content in the form of byte array. A simple example of HTTP request:
public static byte[] GetImageByteArray(string url)
{
try
{
using (var client = new HttpClient())
{
var uri = new Uri(url);
var response = client.GetAsync(uri).Result;
if (response.IsSuccessStatusCode)
{
var content = response.Content.ReadAsByteArrayAsync();
return content.Result;
}
}
return null;
}
catch
{
return null;
}
}
Next, you can simply bind the output from your result into your image source and the image to your content:
var mainStack = new StackLayout();
var imageByteArray = GetImageByteArray("https://static.pexels.com/photos/34950/pexels-photo.jpg");
Image image;
if (imageByteArray != null)
{
image = new Image()
{
Source = ImageSource.FromStream(() => new MemoryStream(imageByteArray))
};
mainStack.Children.Add(image);
}
Content = mainStack;
I am trying to use EPPlus in my EF WebApi to return data in a excel workbook.
The call to webserver gets made successfully, but when my browser opens the excel doc... all the content is gibberish.
This is my webapi
private xxxV003Context db = new xxxV003Context();
[HttpGet]
public HttpResponseMessage Get()
{
HttpResponseMessage response;
response = Request.CreateResponse(HttpStatusCode.OK);
MediaTypeHeaderValue mediaType = new MediaTypeHeaderValue("application/octet-stream");
//MediaTypeHeaderValue mediaType = new MediaTypeHeaderValue("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
response.Content = new StreamContent(ExcelSheet());
response.Content.Headers.ContentType = mediaType;
response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment");
response.Content.Headers.ContentDisposition.FileName = "Orders.xlsx";
return response;
}
public List<Client> Orders()
{
List<Client> tList = new List<Client>();
using (db)
{
tList.Add(new Client { ClientID = 50, ClientName = "testName1" });
tList.Add(new Client { ClientID = 51, ClientName = "testName2" });
}
return tList;
}
public MemoryStream ExcelSheet()
{
using (var package = new ExcelPackage())
{
var worksheet = package.Workbook.Worksheets.Add("Orders");
worksheet.Cells["A1"].LoadFromCollection(Orders(), false);
package.Save();
var stream = new MemoryStream(package.GetAsByteArray());
return stream;
}
}
here is the screenshot
NEW ERROR MESSAGE
<?xml version="1.0" encoding="UTF-8" standalone="true"?>
-<recoveryLog xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main">
<logFileName>error125800_03.xml</logFileName>
<summary>Errors were detected in file 'C:\Users\xxx\Downloads\Orders (2).xlsx'</summary>
-<additionalInfo>
<info>Excel completed file level validation and repair. Some parts of this workbook may have been repaired or discarded.</info>
</additionalInfo>
</recoveryLog>
EPPlus creates .xlsx files - Change the file extension from .xls to .xlsx
I am attempting to upload an image using MVC 6; however, I am not able to find the class HttpPostedFileBase. I have checked the GitHub and did not have any luck. Does anyone know the correct way to upload a file in MVC6?
MVC 6 used another mechanism to upload files. You can get more examples on GitHub or other sources. Just use IFormFile as a parameter of your action or a collection of files or IFormFileCollection if you want upload few files in the same time:
public async Task<IActionResult> UploadSingle(IFormFile file)
{
FileDetails fileDetails;
using (var reader = new StreamReader(file.OpenReadStream()))
{
var fileContent = reader.ReadToEnd();
var parsedContentDisposition = ContentDispositionHeaderValue.Parse(file.ContentDisposition);
var fileName = parsedContentDisposition.FileName;
}
...
}
[HttpPost]
public async Task<IActionResult> UploadMultiple(ICollection<IFormFile> files)
{
var uploads = Path.Combine(_environment.WebRootPath,"uploads");
foreach(var file in files)
{
if(file.Length > 0)
{
var fileName = ContentDispositionHeaderValue.Parse(file.ContentDisposition).FileName.Trim('"');
await file.SaveAsAsync(Path.Combine(uploads,fileName));
}
...
}
}
You can see current contract of IFormFile in asp.net sources. See also ContentDispositionHeaderValue for additional file info.
There is no HttpPostedFileBase in MVC6. You can use IFormFile instead.
Example: https://github.com/aspnet/Mvc/blob/dev/test/WebSites/ModelBindingWebSite/Controllers/FileUploadController.cs
Snippet from the above link:
public FileDetails UploadSingle(IFormFile file)
{
FileDetails fileDetails;
using (var reader = new StreamReader(file.OpenReadStream()))
{
var fileContent = reader.ReadToEnd();
var parsedContentDisposition = ContentDispositionHeaderValue.Parse(file.ContentDisposition);
fileDetails = new FileDetails
{
Filename = parsedContentDisposition.FileName,
Content = fileContent
};
}
return fileDetails;
}
I was searching around for quite a while trying to piece this together in .net core and ended up with the below. The Base64 conversion will be next to be done so that the retrieval and display is a little easier. I have used IFormFileCollection to be able to do multiple files.
[HttpPost]
public async Task<IActionResult> Create(IFormFileCollection files)
{
Models.File fileIn = new Models.File();
if(model != null && files != null)
{
foreach (var file in files)
{
if (file.Length > 0)
{
var fileName = ContentDispositionHeaderValue.Parse(file.ContentDisposition).FileName.Trim('"');
byte[] fileBytes = null;
using (var fileStream = file.OpenReadStream())
using (var ms = new MemoryStream())
{
fileStream.CopyTo(ms);
fileBytes = ms.ToArray();
//string s = Convert.ToBase64String(fileBytes);
// act on the Base64 data
}
fileIn.Filename = fileName;
fileIn.FileLength = Convert.ToInt32(file.Length);
fileIn.FileType = file.ContentType;
fileIn.FileTypeId = model.FileTypeId;
fileIn.FileData = fileBytes;
_context.Add(fileIn);
await _context.SaveChangesAsync();
}
}
}
return View();
}
EDIT
And below is return of files to a list and then download.
public JsonResult GetAllFiles()
{
var files = _context.File
.Include(a => a.FileCategory)
.Select(a => new
{
id = a.Id.ToString(),
fileName = a.Filename,
fileData = a.FileData,
fileType = a.FileType,
friendlyName = a.FriendlyName,
fileCategory = a.FileCategory.Name.ToLower()
}).ToList();
return Json(files);
}
public FileStreamResult DownloadFileById(int id)
{
// Fetching file encoded code from database.
var file = _context.File.SingleOrDefault(f => f.Id == id);
var fileData = file.FileData;
var fileName = file.Filename;
// Converting to code to byte array
byte[] bytes = Convert.FromBase64String(fileData);
// Converting byte array to memory stream.
MemoryStream stream = new MemoryStream(bytes);
// Create final file stream result.
FileStreamResult fileStream = new FileStreamResult(stream, "*/*");
// File name with file extension.
fileStream.FileDownloadName = fileName;
return fileStream;
}
We are using asp.net web api in our application, in that we are trying to return the response with content-type with text/plain format but We are unable to succeeded. Same thing we tried with ASP.NET MVC it is working fine could you please provide me equivalent solution in Web API.
Please find below for the function implemented in ASP.NET MVC
public JsonResult FileUpload(HttpPostedFileBase file)
{
string extension = System.IO.Path.GetExtension(file.FileName);
string bufferData = string.Empty;
if (file != null)
{
using (MemoryStream ms = new MemoryStream())
{
file.InputStream.CopyTo(ms);
byte[] array = ms.GetBuffer();
var appendInfo = "data:image/" + extension + ";base64,";
bufferData = appendInfo + Convert.ToBase64String(array);
}
}
var result = new
{
Data = bufferData
};
return Json(result,"text/plain");
}
Could you please suggest same implementation in WebAPI.
Thanks,
Bhagat
Web Api does the JSON work for you, so you can simplify your code handling on the endpoint. By default, you need to make changes in your WebApiConfig.cs for everything to work nicely. I've modified your method below:
public HttpResponseMessage FileUpload(HttpPostedFileBase file) {
var result = new HttpResponseMessage(HttpStatusCode.NotFound);
var bufferData = string.Empty;
try
{
if (file != null)
{
var extension = System.IO.Path.GetExtension(file.FileName);
using (MemoryStream ms = new MemoryStream())
{
file.InputStream.CopyTo(ms);
var array = ms.GetBuffer();
var appendInfo = "data:image/" + extension + ";base64,";
bufferData = appendInfo + Convert.ToBase64String(array);
result.StatusCode = HttpStatusCode.OK;
// Set Headers and Content here
result.Content = bufferData;
}
}
}
catch(IOException ex)
{
// Handle IO Exception
}
return result
}
The changes you need to make in your WebApiConfig.cs could look like this:
public static void Register(HttpConfiguration config)
{
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{action}",
defaults: null,
constraints: new { action = #"\D+" }
);
// This makes the response default into JSON instead of XML
config.Formatters.Remove(config.Formatters.XmlFormatter);
}
As a note, the very fastest fix you can make to your code would be to do this, but I don't recommend returning strings.
public string FileUpload(HttpPostedFileBase file) {
var result = new HttpResponseMessage(HttpStatusCode.NotFound);
var bufferData = string.Empty;
if (file != null)
{
var extension = System.IO.Path.GetExtension(file.FileName);
using (MemoryStream ms = new MemoryStream())
{
file.InputStream.CopyTo(ms);
var array = ms.GetBuffer();
var appendInfo = "data:image/" + extension + ";base64,";
bufferData = appendInfo + Convert.ToBase64String(array);
return bufferData;
}
}
// If you get here and have not returned,
// something went wrong and you should return an Empty
return String.Empty;
}
Good luck - there's lots of ways of handling files and file returns, so I want to assume you don't have some special return value on your handling.