My server has an API to upload files and convert them to PDF. Right now, the file gets uploaded, saved to disk and then converted. See the (trimmed down) code below:
public class ConversionController : ApiController {
public async Task<HttpResponseMessage> PostData() {
var root = HttpContext.Current.Server.MapPath("~/App_Data");
var provider = new MultipartFormDataStreamProvider(root);
await Request.Content.ReadAsMultipartAsync(provider);
var file = provider.FileData.First();
var originalName = file.Headers.ContentDisposition.FileName;
var fileStream = new FileStream(file.LocalFileName, FileMode.Open, FileAccess.Read);
// convert file stream and return the PDF response ...
}
}
As you can see, I read the file to disk but then immediately get a stream for it so I can feed it to our conversion function (which takes a stream). This seems like a waste to save the file to disk every time. So instead of ReadAsMultipartAsync() which saves to disk, I can use ReadAsStreamAsync() which will give me the stream that I can give directly to the conversion function.
The problem that I'm having with ReadAsMultipartAsync() is that I can't figure out how to get the original file name without having the MultipartFileData instance to work with. I know that the name comes with the request as part of the body, but I can't figure out how to access it. How can I get the name of the uploaded file without writing the uploaded file to disk?
You can use MultipartMemoryStreamProvider, for example:
var provider = new MultipartMemoryStreamProvider();
var task = Request.Content.ReadAsMultipartAsync(provider).ContinueWith(t =>
{
var file = provider.Contents.First();
var fileContents = await file.ReadAsByteArrayAsync();
var filename = file.Headers.ContentDisposition.FileName.Replace("\"", string.Empty);
/// do other stuff
return Request.CreateResponse(HttpStatusCode.OK);
});
In this case the content is read as a byte array, but the same applies to streams.
Related
I have an html document that I created using syncfution, but what I wantt to do, is to share this document as word or pdf but mantaning the format (Bullets, color, etc).
I also tried to use syncfution to make the convertion, but it dosent work
For example I manage to upload it to Azure in word format, but the formating, and styles are gone
private async void ShareOptionsAction() {
var share = DependencyService.Get<IShare>();
var localFolder = FileSystem.AppDataDirectory;
string fileName = $"{NoteName}.docx";
var filePath = Path.Combine(localFolder, fileName);
using (WordDocument document = new WordDocument()) {
//Loads or opens an existing Word document from stream
Stream inputStream = assembly.GetManifestResourceStream(HtmlText);
//Loads or opens an existing Word document through Open method of WordDocument class
document.Open(inputStream, FormatType.Html);
//Creates an instance of memory stream
using (FileStream fileStream = new FileStream(filePath, FileMode.Create, FileAccess.ReadWrite)) {
//Saves the Word document to file stream.
document.Save(fileStream, FormatType.Docx);
}
//Closes the document
document.Close();
}
await App.AzureService.UploadToAzureBlobStorage(filePath, fileName);
This will convert it fine, but I loose all the formatng
is there any way to do this with a third party? and maintain the formatting
I am creating an app where user can upload their text file and find out about its most used word.
I have tried to follow this doc to get used to the idea of using AZURE STORAGE BLOBS - https://learn.microsoft.com/en-us/azure/storage/blobs/storage-quickstart-blobs-dotnet
But I am super newbie and having a hard time figuring it out how to adapt those blobs methods for my POST method.
This my sudo - what I think I need in my controller and what needs to happen when POST method is triggered.
a.No need for DELETE or PUT, not replacing the data nor deleting in this app
b.Maybe need a GET method, but as soon as POST method is triggered, it should pass the text context to the FE component
POST method
connect with azure storage account
if it is a first time of POST, create a container to store the text file
a. how can I connect with the existing container if the new container has already been made? I found this, but this is for the old CloudBlobContainer. Not the new SDK 12 version.
.GetContainerReference($"{containerName}");
upload the text file to the container
get the chosen file's text content and return
And here is my controller.
public class HomeController : Controller
{
private IConfiguration _configuration;
public HomeController(IConfiguration Configuration)
{
_configuration = Configuration;
}
public IActionResult Index()
{
return View();
}
[HttpPost("UploadText")]
public async Task<IActionResult> Post(List<IFormFile> files)
{
if (files != null)
{
try
{
string connectionString = Environment.GetEnvironmentVariable("AZURE_STORAGE_CONNECTION_STRING");
BlobServiceClient blobServiceClient = new BlobServiceClient(connectionString);
string containerName = "textdata" + Guid.NewGuid().ToString();
BlobContainerClient containerClient = await blobServiceClient.CreateBlobContainerAsync(containerName);
//Q. How to write a if condition here so if the POST method has already triggered and container already created, just upload the data. Do not create a new container?
string fileName = //Q. how to get the chosen file name and replace with newly assignmed name?
string localFilePath = //Q. how to get the local file path so I can pass on to the FileStream?
BlobClient blobClient = containerClient.GetBlobClient(fileName);
using FileStream uploadFileStream = System.IO.File.OpenRead(localFilePath);
await blobClient.UploadAsync(uploadFileStream, true);
uploadFileStream.Close();
string data = System.IO.File.ReadAllText(localFilePath, Encoding.UTF8);
//Q. If I use fetch('Home').then... from FE component, will it receive this data? in which form will it receive? JSON?
return Content(data);
}
catch
{
//Q. how to use storageExeption for the error messages
}
finally
{
//Q. what is suitable to execute in finally? return the Content(data) here?
if (files != null)
{
//files.Close();
}
}
}
//Q. what to pass on inside of the Ok() in this scenario?
return Ok();
}
}
Q1. How can I check if the POST method has been already triggered, and created the Container? If so how can I get the container name and connect to it?
Q2. Should I give a new assigned name to the chosen file? How can I do so?
Q3. How can I get the chosen file's name so I can pass in order to process Q2?
Q4. How to get the local file path so I can pass on to the FileStream?
Q5. How to return the Content data and pass to the FE? by using fetch('Home').then... like this?
Q6. How can I use storageExeption for the error messages
Q7. What is suitable to execute in finally? return the Content(data) here?
Q8. What to pass on inside of the Ok() in this scenario?
Any help is welcomed! I know I asked a lot of Qs here. Thanks a lot!
Update: add a sample code, you can modify it as per your need.
[HttpPost]
public async Task<IActionResult> SaveFile(List<IFormFile> files)
{
if (files == null || files.Count == 0) return Content("file not selected");
string connectionString = "xxxxxxxx";
BlobServiceClient blobServiceClient = new BlobServiceClient(connectionString);
string containerName = "textdata" + Guid.NewGuid().ToString();;
BlobContainerClient containerClient = blobServiceClient.GetBlobContainerClient(containerName);
containerClient.CreateIfNotExists();
foreach (var file in files)
{
//use this line of code to get file name
string fileName = Path.GetFileName(file.FileName);
BlobClient blobClient = containerClient.GetBlobClient(fileName);
//directly read file content
using (var stream = file.OpenReadStream())
{
await blobClient.UploadAsync(stream);
}
}
//other code
return View();
}
Original answer:
When using List<IFormFile>, you should use foreach code block to iterate each file in the list.
Q2. Should I give a new assigned name to the chosen file? How can I do
so?
If you want to keep the file original name, in the foreach statement like below:
foreach (var file in myfiles)
{
Path.GetFileName(file.FileName)
//other code
}
And if you want to assign a new file name when uploaded to blob storage, you should define the new name in this line of code: BlobClient blobClient = containerClient.GetBlobClient("the new file name").
Q3. How can I get the chosen file's name so I can pass in order to
process Q2?
refer to Q2.
Q4. How to get the local file path so I can pass on to the FileStream?
You can use code like this: string localFilePath = file.FileName; to get the path, and then combine with the file name. But there is a better way, you can directly use this line of code Stream uploadFileStream = file.OpenReadStream().
Q5. How to return the Content data and pass to the FE? by using
fetch('Home').then... like this?
Not clear what's it meaning. Can you provide more details?
Q6. How can I use storageExeption for the error messages
The storageExeption does not exist in the latest version, you should install the older one.
You can refer to this link for more details.
#Ivan's answer is what the documentation seems the recommend; however, I was having a strange issue where my stream was always prematurely closed before the upload had time to complete. To anyone else who might run into this problem, going the BinaryData route helped me. Here's what that looks like:
await using var ms = new MemoryStream();
await file.CopyToAsync(ms);
var data = new BinaryData(ms.ToArray());
await blobClient.UploadAsync(data);
I am trying to upload a file onto my Drive using Google Drive .NET API v3. My code is below
static string[] Scopes = { DriveService.Scope.Drive,
DriveService.Scope.DriveAppdata,
DriveService.Scope.DriveFile,
DriveService.Scope.DriveMetadataReadonly,
DriveService.Scope.DriveReadonly,
DriveService.Scope.DriveScripts };
static string ApplicationName = "Drive API .NET Quickstart";
public ActionResult Index()
{
UserCredential credential;
using (var stream =
new FileStream("C:/Users/admin1/Documents/visual studio 2017/Projects/TryGoogleDrive/TryGoogleDrive/client_secret.json", FileMode.Open, FileAccess.Read))
{
string credPath = Environment.GetFolderPath(
System.Environment.SpecialFolder.Personal);
credPath = Path.Combine(credPath, ".credentials/drive-dotnet-quickstart.json");
credential = GoogleWebAuthorizationBroker.AuthorizeAsync(
GoogleClientSecrets.Load(stream).Secrets,
Scopes,
"user",
CancellationToken.None,
new FileDataStore(credPath, true)).Result;
Debug.WriteLine("Credential file saved to: " + credPath);
}
// Create Drive API service.
var service = new DriveService(new BaseClientService.Initializer()
{
HttpClientInitializer = credential,
ApplicationName = ApplicationName,
});
// Define parameters of request.
FilesResource.ListRequest listRequest = service.Files.List();
listRequest.PageSize = 10;
listRequest.Fields = "nextPageToken, files(id, name)";
// List files.
IList<Google.Apis.Drive.v3.Data.File> files = listRequest.Execute()
.Files;
Debug.WriteLine("Files:");
if (files != null && files.Count > 0)
{
foreach (var file in files)
{
Debug.WriteLine("{0} ({1})", file.Name, file.Id);
}
}
else
{
Debug.WriteLine("No files found.");
}
var fileMetadata = new Google.Apis.Drive.v3.Data.File()
{
Name = "report.csv",
MimeType = "text/csv",
};
FilesResource.CreateMediaUpload request;
using (var stream = new FileStream("C:/debugging/report.csv",
FileMode.Open))
{
request = service.Files.Create(
fileMetadata, stream, "text/csv");
request.Fields = "id";
request.Upload();
}
var response = request.ResponseBody;
Console.WriteLine("File ID: " + response.Id);
return View();
}
The problem I'm facing is that response is always null. I looked into it a bit further and found that the request returned a 403 resultCode. I also took a look at some other questions on SO this and this but neither were of any help.
Edit: I forgot to mention that the first part of the code is working correctly - it lists all the files in my Drive. Only the second part is not working (the upload file part)
string[] Scopes = { DriveService.Scope.Drive };
Change the Drive scope then delete the file token.json
in vs2017 you can see token.json file in token.json folder when client_secret.json file present.
Try to visit this post from ASP.NET forum.
The same idea as what you want to do in your app, since you are dealing with uploading a file in Google Drive using .net.
You may try to call rest api directly to achieve your requirement :
The quickstart from .net will help you to make requests from/to the Drive API.
Upload Files:
The Drive API allows you to upload file data when create or
updating a File resource.
You can send upload requests in any of the following ways:
Simple upload: uploadType=media. For quick transfer of a small file (5 MB or less). To perform a simple upload, refer to Performing
a Simple Upload.
Multipart upload: uploadType=multipart. For quick transfer of a small file (5 MB or less) and metadata describing the file, all in a
single request. To perform a multipart upload, refer to Performing a
Multipart Upload.
Resumable upload: uploadType=resumable. For more reliable transfer, especially important with large files. Resumable uploads are
a good choice for most applications, since they also work for small
files at the cost of one additional HTTP request per upload. To
perform a resumable upload, refer to Performing a Resumable
Upload.
You may try this code from the documentation on uploading sample file.
var fileMetadata = new File()
{
Name = "photo.jpg"
};
FilesResource.CreateMediaUpload request;
using (var stream = new System.IO.FileStream("files/photo.jpg",
System.IO.FileMode.Open))
{
request = driveService.Files.Create(
fileMetadata, stream, "image/jpeg");
request.Fields = "id";
request.Upload();
}
var file = request.ResponseBody;
Console.WriteLine("File ID: " + file.Id);
You may check the errors you may encounter in this documentation.
Have a look at what request.Upload() returns. For me when I was having this issue it returned:
Insufficient Permission Errors [Message[Insufficient Permission] Location[ - ]
I changed my scope from DriveService.Scope.DriveReadonly to DriveService.Scope.Drive and I was in business.
Change static string[] Scopes = { DriveService.Scope.DriveReadonly }; to static string[] Scopes = { DriveService.Scope.Drive };.
After changes, take a look into token.json file and check does it change its scope from DriveReadonly to Drive.
If you are seeing DriveReadonly then delete the token.json file and run the application again.
I have a form that uploads multiple files. My model has a List<HttpPostedFileBase> called SchemaFileBases, which is correctly binded. I need to upload these files to s3 and would like to do it in parallel. I'm unable to use asyc and await because this code is run from both ASP.Net and a queue based application that currently doesn't have async/await support (working on it).
If I change the foreach below to Parallel.ForEach(this.SchemaFileBases, schemaFileBase => {... Then I get some funkiness going on. The two files end up being mashed. Each file will contain some of the other files content after it's uploaded. AwsDocument is being used elsewhere in parallel so I don't think it has to do with that. Each AwsDocument has it's own AmazonS3Client.
public override void UploadToS3(IMetadataParser parser)
{
string hash;
string key;
foreach (var schemaFileBase in this.SchemaFileBases)
{
AwsDocument aws = new AwsDocument(AwsBucket.Received);
hash = schemaFileBase.InputStream.Md5Hash().ToByteArray().ToHex();
key = String.Format("{0}/{1}", this.S3Prefix, schemaFileBase.FileName);
Stream inputStream = schemaFileBase.InputStream;
aws.UploadToS3(key, inputStream, hash);
}
}
My coworker suspect's it's something to do with how the InputStream on the HttpPostedFileBase is implemented. Perhaps it is not thread safe, and the streams are both reading from the original request at the same time? I can't imagine MS would do that though.
Multi-threaded version:
public override void UploadToS3(IMetadataParser parser)
{
Parallel.ForEach(this.SchemaFileBases, f =>
{
AwsDocument aws = new AwsDocument(AwsBucket.Received);
string hash = f.InputStream.Md5Hash().ToByteArray().ToHex();
string key = String.Format("{0}/{1}", this.S3Prefix, f.FileName);
Stream inputStream = f.InputStream;
aws.UploadToS3(key, inputStream, hash);
});
}
Above solution is what I tried to multi-thread it. Does not work (files get mixed up all weird).
I am making a windows phone 8 application. Part of this application requires state to be saved. I am saving it as a string of Json. If I open the application, save some data, exit the application and the load it again, it hangs on either GetFolderAsync or OpenStreamForReadAsync. It does not happen every time, but once it starts hanging, I have to kill the whole emulator and make a new one to start the application again.
I have even tried just making an empty file with no data in it and the problem still persistes.
Below is the code I am using to save and load the data. It does not matter where I call the data load whether it be on application start or on the form load it still breaks.
private async Task SaveLists()
{
//XmlSerializer serializer = new XmlSerializer(typeof(ListHolder));
// Get the local folder.
StorageFolder local = Windows.Storage.ApplicationData.Current.LocalFolder;
// Create a new folder name DataFolder.
var dataFolder = await local.CreateFolderAsync("DataFolder",
CreationCollisionOption.OpenIfExists);
// Create a new file named DataFile.txt.
var file = await dataFolder.CreateFileAsync("Lists.json",
CreationCollisionOption.ReplaceExisting);
string json = JsonConvert.SerializeObject(Lists, Formatting.Indented);
byte[] fileBytes = System.Text.Encoding.UTF8.GetBytes(json.ToCharArray());
using (var s = await file.OpenStreamForWriteAsync())
{
s.Write(fileBytes, 0, fileBytes.Length);
}
}
private async Task LoadLists()
{
// Get the local folder.
StorageFolder local = Windows.Storage.ApplicationData.Current.LocalFolder;
if (local != null)
{
try
{
// Get the DataFolder folder.
var dataFolder = await local.GetFolderAsync("DataFolder");
// Get the file.
var files = dataFolder.GetFilesAsync();
var file = await dataFolder.OpenStreamForReadAsync("Lists.json");
string jsonString = "";
// Read the data.
using (StreamReader streamReader = new StreamReader(file))
{
jsonString = streamReader.ReadToEnd();
}
if (jsonString.Length > 0)
{
Lists = JsonConvert.DeserializeObject<List<ItemList>>(jsonString);
}
else
{
Lists = new List<ItemList>();
}
}
catch (Exception ex)
{
Lists = new List<ItemList>();
}
}
}
You are causing a deadlock by calling Result. I explain this deadlock on my blog and in a recent MSDN article. In summary, await will (by default) attempt to resume execution within a context (the current SynchronizationContext unless it is null, in which case it uses the current TaskScheduler).
In your case, the current SynchronizationContext is the UI context, which is only used by the UI thread. So when you block the UI thread by calling Result, the async method cannot schedule back to the UI thread to complete.