In an angular 5 app with a .net core backend, a user can upload attachments for his/her projects. The attachments are being send to the .NET Core backend and are saved inside the WebRootPath in a folder with the name of the project code.
[HttpPost]
[Route("api/projects/{id}/upload")]
[Consumes("application/json", "application/json-patch+json", "multipart/form-data")]
public async Task<IActionResult> UploadAttachment(int id, FileForUpload upload)
{
var project = await _orbaAgent.GetDefaultProject(id);
if (upload != null && upload.File != null && upload.File.Length > 0)
{
var file = upload.File;
string serverPath = string.IsNullOrEmpty(_hostingEnvironment.WebRootPath) ? _hostingEnvironment.ContentRootPath : _hostingEnvironment.WebRootPath;
serverPath = Path.Combine(serverPath, "attachments", project.Code);
if (!Directory.Exists(serverPath))
{
Directory.CreateDirectory(serverPath);
}
using (var fileStream = new FileStream(Path.Combine(serverPath, file.FileName), FileMode.Create))
{
await file.CopyToAsync(fileStream);
}
}
return Ok();
}
The location of the attachments becomes 'app/attachments/'projectcode'/.
To download the files, I use an anchor element on the html page
<a href="attachments/{{defaultProject.code}}/{{att.name}}" download>{{att.name}}</a>
Uploading/downloading works perfect.
The only problem is that when I deploy a new version of the application, the app/attachment folder dissapears and so do all of the attachments.
Is there any way to prevent the deletion of this folder for new versions? Or if this is not possible, should I save the files somewhere else?
Related
Just curious about this and wanted to know about this matter.
I have downloaded a PWA app and set it to my ASP.NET MVC project.
In there I want to allow download a file and for that I have used this,
<a download href="#Url.Action("DownloadDoc","Ajax" ,new { id = item.Id})" target="_blank" class="btn-20 btn border-green-dark color-green-dark bi bi-arrow-down" />
The issue is it's not downloading, A new view will appear and the address bar shows the controller and the action, and the file Id, If I inspect this, in the network area I can see the file.
Normally when I used the same in HTML view, it opens up a new tab and then closes with downloading the file.
Here it won't work.
I want to know is there is another way of doing this ??
This is my controller code
public ActionResult DownloadDoc(int id) {
var q = from temp in db.CustomerScannedDocuments where temp.Id == id select temp.Attachment;
var type = from t in db.CustomerScannedDocuments where t.Id == id select t.File_Name;
string fileType = type.First().ToString();
string ext = Path.GetExtension(fileType);
byte[] cover = q.First();
if (cover != null) {
if (ext == ".pdf") {
return File(cover, "application/pdf");
} else {
return File(cover, "image/jpg");
}
} else {
return null;
}
}
I want to know is there is another way of doing this ?
There are couple of ways you could achieve your requirement. You could try in following ways:
Way: 1
Controller:
public async Task<IActionResult> DownloadImage(string imageName)
{
var path = Path.GetFullPath("./wwwroot/ImageName/Cover/" + imageName);
MemoryStream memory = new MemoryStream();
using (FileStream stream = new FileStream(path, FileMode.Open))
{
await stream.CopyToAsync(memory);
}
memory.Position = 0;
return File(memory, "image/png", Path.GetFileName(path));
}
Download Link HTML:
<a asp-controller="Application" asp-action="DownloadImage" class="btn btn-info" asp-route-imageName="#item.ImageName">Download</a>
Output:
Note: It doesn't require any Nuget package
Way: 2 When you want to display PDF on your browser from database Model
Solution:
public ActionResult DisplayPdfOnBrowserFromDatabaseList()
{
var data = _context.Members.ToList();
var pdf = data.ToPdf();
MemoryStream ms = new MemoryStream(pdf);
return new FileStreamResult(ms, "application/pdf");
}
Note: To handle this scenario you need to use 3rd party Nuget package which is ArrayToPdf You can search on Nuget package on your visual studio. You can also check the GitHub Link. Finally need to add using ArrayToPdf; on top.
Output:
Way: 3 When you want to download PDF on your browser from database model or existing file
Solution:
public ActionResult DownloadPDFOnBrowser()
{
var data = _context.Members.ToList();
var byteArray = data.ToPdf();
MemoryStream stream = new MemoryStream(byteArray);
string mimeType = "application/pdf";
return new FileStreamResult(stream, mimeType)
{
FileDownloadName = "DatabaseListToPdf.pdf"
};
}
Note: As described above we need to add using ArrayToPdf; on top. To handle this scenario you need to use 3rd party Nuget package which is ArrayToPdf You can search on Nuget package on your visual studio. See the screenshot below:
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();
}
I am using asp net core 2.0.5 with MVC and want to serve a static folder outside of wwwroot.
My input files would look like below.
wwwroot
staticfolder
10
index.html
image1.png
image2.png
sub-folder
image3.jpg
The index.html is generated by other program. All images are used in the index.html.
We want to server in after checking the authentication, i.e. users can view index.html through a path api/flight/10/index.html. But I need to check the user permission to access resource flight 10.
I understand Physicalfile can be used to serve a static file (e.g. *.png) outside wwwroot, and also configure app.UseStaticFiles to serve folders and files in the startup.cs.
Some pseudo codes for a minimum example.
[Route("api/flight/{flight}/index.html")]
[HttpGet]
public IActionResult GetImageThumbnail(
[FromRoute] int flight)
{
// Check permission
List<Flight> data = _context
.Flight(id: flight)
.ToList();
if (data.Count() == 0)
{
return NotFound("No permission.");
}
// data[0].BaseFolder is a folder outside wwwroot
string filename = data[0].BaseFolder + "/index.html";
// Return the content for index.html
...
}
So my question is how should I server a folder mixed with html and images using the similar method above.
I found a simple solution to achieve my target. Post here in case others have the same problem.
The key thing is to set Route using {*file} which will match any string at the end.
[Route("api/flight/{flight}/{*file}")]
[HttpGet]
public async Task<IActionResult> GetImageThumbnail([FromRoute]int flight,
[FromRoute] string file)
{
// Check permission
List<Flight> data = _context
.Flight(id: flight)
.ToList();
if (data.Count() == 0)
{
return NotFound("No permission.");
}
string filename = Path.Combine(data[0].BaseFolder, file);
var provider = new Microsoft.AspNetCore.StaticFiles.FileExtensionContentTypeProvider();
string minetype = "";
provider.TryGetContentType(filename, out minetype);
return PhysicalFile(filename, minetype);
}
I have written a small method that uploads files on Dropbox and that method is working absolutely fine but the issue is how can I get the URL of the uploaded image so that I hit that URL on browser and it shows me the image.
Here is the code of uploading files:
public static async Task Run()
{
var accessToken = ConfigurationManager.AppSettings["DropBoxAccessToken"];
using (var dbx = new DropboxClient(accessToken))
{
//var full = await dbx.Users.GetCurrentAccountAsync();
await Upload(dbx, "/Test", "Test Image.jpg");
}
}
static async Task Upload(DropboxClient dbx, string folder, string file)
{
var readContent = System.IO.File.ReadAllBytes(#"D:\Images\IMG_20161127_204200968.jpg");
using (var mem = new MemoryStream(readContent))
{
var updated = await dbx.Files.UploadAsync(
folder + "/" + file,
WriteMode.Overwrite.Instance,
body: mem);
var mediaInfo = updated.MediaInfo;
}
}
I have tried to get details of uploaded image by hovering on var updated but didn't get the URL.
Any help?
To get a link to a file via the Dropbox API, you have two options:
GetTemporaryLinkAsync: this returns a temporary link, but isn't meant for being displayed in the browser directly.
CreateSharedLinkWithSettingsAsync: this returns a shared link that points to a preview page for the file that can be displayed in the browser.
I'm working in a function to download pdfs from DropBox, I'm using ASP.net Core , everything works good. The only thing is that when you click in the download link it doesn't show any message and downloads the file. I would like to show the download progress like usually happens when we download something from Internet, I don't want any dialog to appear, just to show that the file was downloaded like normally happens in any browser like Chrome or IE and then have the choices 'Show in Folder' and things like that, what would I need to add?
public async Task DownloadPdf()
{
DropboxClient client2 = new DropboxClient("cU5M-a4exaAAAAAAAAABDVZsKdpPteNmwHslOeFEo-HByuOr4v4ONvXoAMCFyOXH");
string folder = "MyFolder";
string file = "Test PDF.pdf";
using (var response = await client2.Files.DownloadAsync("/" + folder + "/" + file))
{
using (var fileStream = System.IO.File.Create(#"C:\Users\User\Downloads\Test.pdf"))
{
(await response.GetContentAsStreamAsync()).CopyTo(fileStream);
}
}
}
I have a asp.net core project with an API that returns a file:
[HttpGet("{id}")]
public IActionResult Get(int id) {
byte[] fileContent = READ_YOUR_FILE();
FileContentResult result = new FileContentResult(fileContent, "application/octet-stream") {
FileDownloadName = id.ToString()
};
return result;
}
If I access in my browser the URL from this API (myapp/api/mycontroller/id), then I can see the file downloading.