in UWP there are files and permissions restrictions, so we can only acces files directly from few folders or we can use filepicker to access from anywhere on system.
how can I use the files picked from filepicker and use them anytime again when the app runs ? tried to use them again by path but it gives permission error. I know about the "futureacceslist" but its limit is 1000 and also it will make the app slow if I am not wrong? .
Is there a better way to do this ? or can we store storage files link somehow in local sqlite database?
If you need to access lots of files, asking the user to select the parent folder and then storing that is probably a better solution (unless you want to store 1,000 individually-picked files from different locations). You can store StorageFolders in the access list as well.
I'm not sure why you think it will make your app slow, but the only real way to know if this will affect your performance is to try it and measure against your goals.
Considering this method..
public async static Task<byte[]> ToByteArray(this StorageFile file)
{
byte[] fileBytes = null;
using (IRandomAccessStreamWithContentType stream = await file.OpenReadAsync())
{
fileBytes = new byte[stream.Size];
using (DataReader reader = new DataReader(stream))
{
await reader.LoadAsync((uint)stream.Size);
reader.ReadBytes(fileBytes);
}
}
return fileBytes;
}
This class..
public class AppFile
{
public string FileName { get; set; }
public byte[] ByteArray { get; set; }
}
And this variable
List<AppFile> _appFiles = new List<AppFile>();
Just..
var fileOpenPicker = new FileOpenPicker();
IReadOnlyList<StorageFile> files = await fileOpenPicker.PickMultipleFilesAsync();
foreach (var file in files)
{
var byteArray = await file.ToByteArray();
_appFiles.Add(new AppFile { FileName = file.DisplayName, ByteArray = byteArray });
}
UPDATE
using Newtonsoft.Json;
using System.Linq;
using Windows.Security.Credentials;
using Windows.Storage;
namespace Your.Namespace
{
public class StateService
{
public void SaveState<T>(string key, T value)
{
var localSettings = ApplicationData.Current.LocalSettings;
localSettings.Values[key] = JsonConvert.SerializeObject(value);
}
public T LoadState<T>(string key)
{
var localSettings = ApplicationData.Current.LocalSettings;
if (localSettings.Values.ContainsKey(key))
return JsonConvert.DeserializeObject<T>(((string) localSettings.Values[key]));
return default(T);
}
public void RemoveState(string key)
{
var localSettings = ApplicationData.Current.LocalSettings;
if (localSettings.Values.ContainsKey(key))
localSettings.Values.Remove((key));
}
public void Clear()
{
ApplicationData.Current.LocalSettings.Values.Clear();
}
}
}
A bit late, but, yes the future access list will slow down your app in that it returns storagfile, storagefolder, or storeageitem objects. These run via the runtime broker which hits a huge performance barrier at about 400 objects regardless of the host capability
Related
I am using a file upload component that posts the file to an API controller and this works ok but i need to get the progres of the upload.
[HttpPost("upload/single")]
public async Task SingleAsync(IFormFile file)
{
try
{
// Azure connection string and container name passed as an argument to get the Blob reference of the container.
var container = new BlobContainerClient(azureConnectionString, "upload-container");
// Method to create our container if it doesn’t exist.
var createResponse = await container.CreateIfNotExistsAsync();
// If container successfully created, then set public access type to Blob.
if (createResponse != null && createResponse.GetRawResponse().Status == 201)
await container.SetAccessPolicyAsync(Azure.Storage.Blobs.Models.PublicAccessType.Blob);
// Method to create a new Blob client.
var blob = container.GetBlobClient(file.FileName);
// If a blob with the same name exists, then we delete the Blob and its snapshots.
await blob.DeleteIfExistsAsync(Azure.Storage.Blobs.Models.DeleteSnapshotsOption.IncludeSnapshots);
// Create a file stream and use the UploadSync method to upload the Blob.
uploadFileSize = file.Length;
var progressHandler = new Progress<long>();
progressHandler.ProgressChanged += UploadProgressChanged;
using (var fileStream = file.OpenReadStream())
{
await blob.UploadAsync(fileStream, new BlobHttpHeaders { ContentType = file.ContentType },progressHandler:progressHandler);
}
Response.StatusCode = 400;
}
catch (Exception e)
{
Response.Clear();
Response.StatusCode = 204;
Response.HttpContext.Features.Get<IHttpResponseFeature>().ReasonPhrase = "File failed to upload";
Response.HttpContext.Features.Get<IHttpResponseFeature>().ReasonPhrase = e.Message;
}
}
private double GetProgressPercentage(double totalSize, double currentSize)
{
return (currentSize / totalSize) * 100;
}
private void UploadProgressChanged(object sender, long bytesUploaded)
{
uploadPercentage = GetProgressPercentage(uploadFileSize, bytesUploaded);
}
I am posting this file and it does upload but the file upload progress event is inaccurate it says the file upload is complete after a few seconds when in reality the file takes ~90 secs on my connection to appear in the Azure Blob Storage container.
So in the code above i have the progress handler which works (I can put a break point on it and see it increasing) but how do I return this value to the UI?
I found one solution that used Microsoft.AspNetCore.SignalR but I can't manage to integrate this into my own code and I'm not even sure if I'm on the right track.
using BlazorReportProgress.Server.Hubs;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.SignalR;
using System.Threading;
namespace BlazorReportProgress.Server.Controllers
{
[ApiController]
[Route("api/[controller]")]
public class SlowProcessController : ControllerBase
{
private readonly ILogger<SlowProcessController> _logger;
private readonly IHubContext<ProgressHub> _hubController;
public SlowProcessController(
ILogger<SlowProcessController> logger,
IHubContext<ProgressHub> hubContext)
{
_logger = logger;
_hubController = hubContext;
}
[HttpGet("{ClientID}")]
public IEnumerable<int> Get(string ClientID)
{
List<int> retVal = new();
_logger.LogInformation("Incoming call from ClientID : {ClientID}", ClientID);
_hubController.Clients.Client(ClientID).SendAsync("ProgressReport", "Starting...");
Thread.Sleep(1000);
for (int loop = 0; loop < 10; loop++)
{
_hubController.Clients.Client(ClientID).SendAsync("ProgressReport", loop.ToString());
retVal.Add(loop);
Thread.Sleep(500);
}
_hubController.Clients.Client(ClientID).SendAsync("ProgressReport", "Done!");
return retVal;
}
}
}
I read the Steve Sandersen blog but this says not to use the code as its been superceded by inbuilt blazor functionality.
My application is only for a few users and so i'm not too worried about backend APIs etc, If the upload component used a service not a controller I could more easily get the progress, but the compoents all seem to post to controllers.
Can anyone please enlighten me as to the best way to solve this?
I structured my project into multiple mobile services, grouped by the application type eg:
my-core.azure-mobile.net (user, device)
my-app-A.azure-mobile.net (sales, order, invoice)
my-app-B.azure-mobile.net (inventory & parts)
I'm using custom authentication for all my services, and I implemented my own SSO by setting the same master key to all 3 services.
Things went well when I tested using REST client, eg. user who "logged in" via custom api at my-core.azure-mobile.net is able to use the returned JWT token to access restricted API of the other mobile services.
However, in my xamarin project, only the first (note, in sequence of creation) MobileServiceClient object is working properly (eg. returning results from given table). The client object are created using their own url and key respectively, and stored in a dictionary.
If i created client object for app-A then only create for app-B, I will be able to perform CRUD+Sync on sales/order/invoice entity, while CRUD+Sync operation on inventory/part entity will just hang there. The situation is inverse if I swap the client object creation order.
I wonder if there is any internal static variables used within the MobileServiceClient which caused such behavior, or it is a valid bug ?
=== code snippet ===
public class AzureService
{
IDictionary<String, MobileServiceClient> services = new Dictionary<String, MobileServiceClient>();
public MobileServiceClient Init (String key, String applicationURL, String applicationKey)
{
return services[key] = new MobileServiceClient (applicationURL, applicationKey);
}
public MobileServiceClient Get(String key)
{
return services [key];
}
public void InitSyncContext(MobileServiceSQLiteStore offlineStore)
{
// Uses the default conflict handler, which fails on conflict
// To use a different conflict handler, pass a parameter to InitializeAsync.
// For more details, see http://go.microsoft.com/fwlink/?LinkId=521416
var syncHandler = new MobileServiceSyncHandler ();
foreach(var client in services) {
client.Value.SyncContext.InitializeAsync (offlineStore, syncHandler);
}
}
public void SetAuthenticationToken(String uid, String token)
{
var user = new MobileServiceUser(uid);
foreach(var client in services) {
client.Value.CurrentUser = user;
client.Value.CurrentUser.MobileServiceAuthenticationToken = token;
}
}
public void ClearAuthenticationToken()
{
foreach(var client in services) {
client.Value.CurrentUser = null;
}
}
}
=== more code ===
public class DatabaseService
{
public static MobileServiceSQLiteStore LocalStore = null;
public static string Path { get; set; }
public static ISet<IEntityMappingProvider> Providers = new HashSet<IEntityMappingProvider> ();
public static void Init (String dbPath)
{
LocalStore = new MobileServiceSQLiteStore(dbPath);
foreach(var provider in Providers) {
var types = provider.GetSupportedTypes ();
foreach(var t in types) {
JObject item = null;
// omitted detail to create JObject using reflection on given type
LocalStore.DefineTable(tableName, item);
}
}
}
}
=== still code ===
public class AzureDataSyncService<T> : IAzureDataSyncService<T>
{
public MobileServiceClient ServiceClient { get; set; }
public virtual Task<List<T>> GetAll()
{
try
{
var theTable = ServiceClient.GetSyncTable<T>();
return theTable.ToListAsync();
}
catch (MobileServiceInvalidOperationException msioe)
{
Debug.WriteLine("GetAll<{0}> EXCEPTION TYPE: {1}, EXCEPTION:{2}", typeof(T).ToString(), msioe.GetType().ToString(), msioe.ToString());
}
catch (Exception e)
{
Debug.WriteLine("GetAll<{0}> EXCEPTION TYPE: {1}, EXCEPTION:{2}", typeof(T).ToString(), e.GetType().ToString(), e.ToString());
}
List<T> theCollection = Enumerable.Empty<T>().ToList();
return Task.FromResult(theCollection);
}
}
=== code ===
public class UserService : AzureDataSyncService<User>
{
}
public class PartService : AzureDataSyncService<Part>
{
}
const string coreApiURL = #"https://my-core.azure-mobile.net/";
const string coreApiKey = #"XXXXX";
const string invApiURL = #"https://my-inventory.azure-mobile.net/";
const string invApiKey = #"YYYYY";
public async void Foo ()
{
DatabaseService.Providers.Add (new CoreDataMapper());
DatabaseService.Providers.Add (new InvDataMapper ());
DatabaseService.Init (DatabaseService.Path);
var coreSvc = AzureService.Instance.Init ("Core", coreApiURL, coreApiKey);
var invSvc = AzureService.Instance.Init ("Inv", invApiURL, invApiKey);
AzureService.Instance.InitSyncContext (DatabaseService.LocalStore);
AzureService.Instance.SetAuthenticationToken("AAA", "BBB");
UserService.Instance.ServiceClient = coreSvc;
PartService.Instance.ServiceClient = invSvc;
var x = await UserService.GetAll(); // this will work
var y = await PartService.GetAll(); // but not this
}
It's ok to use multiple MobileServiceClient objects, but not with the same local database. The offline sync feature uses a particular system tables to keep track of table operations and errors, and it is not supported to use the same local store across multiple sync contexts.
I'm not totally sure why it is hanging in your test, but it's possible that there is a lock on the local database file and the other sync context is waiting to get access.
You should instead use different local database files for each service and doing push and pull on each sync context. With your particular example, you just need to move LocalStore out of DatabaseService and into a dictionary in AzureService.
In general, it seems like an unusual design to use multiple services from the same client app. Is there a particular reason that the services need to be separated from each other?
I want to use RazorEngine to generate some html files. It's easy to generate strings first, then write them to files. But if the generated strings are too large, that will cause memory issues.
So I wonder is there a non-cached way to use RazorEngine, like using StreamWriter as its output rather than a string.
I google this for a while, but with no luck.
I think use a custom base template should be the right way, but the documents are so few(even out of date) on the offcial homepage of RazorEngine.
Any hint will be helpful!
OK. I figured it out.
Create a class that inherits TemplateBase<T>, and take a TextWrite parameter in the constructor.
public class TextWriterTemplate<T> : TemplateBase<T>
{
private readonly TextWriter _tw;
public TextWriterTemplate(TextWriter tw)
{
_tw = tw;
}
// override Write and WriteLiteral methods, write text using the TextWriter.
public override void Write(object value)
{
_tw.Write(value);
}
public override void WriteLiteral(string literal)
{
_tw.Write(literal);
}
}
Then use the template as this:
private static void Main(string[] args)
{
using (var sw = new StreamWriter(#"output.txt"))
{
var config = new FluentTemplateServiceConfiguration(c =>
c.WithBaseTemplateType(typeof(TextWriterTemplate<>))
.ActivateUsing(context => (ITemplate)Activator.CreateInstance(context.TemplateType, sw))
);
using (var service = new TemplateService(config))
{
service.Parse("Hello #Model.Name", new {Name = "Waku"}, null, null);
}
}
}
The content of output.txt should be Hello WAKU.
We're making an ASP.Net MVC app that needs to be able to generate a PDF and display it to the screen or save it somewhere easy for the user to access. We're using PdfSharp to generate the document. Once it's finished, how do we let the user save the document or open it up in a reader? I'm especially confused because the PDF is generated server-side but we want it to show up client-side.
Here is the MVC controller to create the report that we have written so far:
public class ReportController : ApiController
{
private static readonly string filename = "report.pdf";
[HttpGet]
public void GenerateReport()
{
ReportPdfInput input = new ReportPdfInput()
{
//Empty for now
};
var manager = new ReportPdfManagerFactory().GetReportPdfManager();
var documentRenderer = manager.GenerateReport(input);
documentRenderer.PdfDocument.Save(filename); //Returns a PdfDocumentRenderer
Process.Start(filename);
}
}
When this runs, I get an UnauthorizedAccessException at documentRenderer.PdfDocument.Save(filename); that says, Access to the path 'C:\Program Files (x86)\Common Files\Microsoft Shared\DevServer\10.0\report.pdf' is denied. I'm also not sure what will happen when the line Process.Start(filename); is executed.
This is the code in manager.GenerateReport(input):
public class ReportPdfManager : IReportPdfManager
{
public PdfDocumentRenderer GenerateReport(ReportPdfInput input)
{
var document = CreateDocument(input);
var renderer = new PdfDocumentRenderer(true, PdfSharp.Pdf.PdfFontEmbedding.Always);
renderer.Document = document;
renderer.RenderDocument();
return renderer;
}
private Document CreateDocument(ReportPdfInput input)
{
//Put content into the document
}
}
Using Yarx's suggestion and PDFsharp Team's tutorial, this is the code we ended up with:
Controller:
[HttpGet]
public ActionResult GenerateReport(ReportPdfInput input)
{
using (MemoryStream stream = new MemoryStream())
{
var manager = new ReportPdfManagerFactory().GetReportPdfManager();
var document = manager.GenerateReport(input);
document.Save(stream, false);
return File(stream.ToArray(), "application/pdf");
}
}
ReportPdfManager:
public PdfDocument GenerateReport(ReportPdfInput input)
{
var document = CreateDocument(input);
var renderer = new PdfDocumentRenderer(true,
PdfSharp.Pdf.PdfFontEmbedding.Always);
renderer.Document = document;
renderer.RenderDocument();
return renderer.PdfDocument;
}
private Document CreateDocument(ReportPdfInput input)
{
//Creates a Document and puts content into it
}
I'm not familar with PDF sharp but for MVC is mostly done via built in functionality. You need to get your pdf document represented as an array of bytes. Then you'd simply use MVC's File method to return it to the browser and let it handle the download. Are there any methods on their class to do that?
public class PdfDocumentController : Controller
{
public ActionResult GenerateReport(ReportPdfInput input)
{
//Get document as byte[]
byte[] documentData;
return File(documentData, "application/pdf");
}
}
I'm trying to write a target for NLog to send messages out to connected clients using SignalR.
Here's what I have now. What I'm wondering is should I be using resolving the ConnectionManager like this -or- somehow obtain a reference to the hub (SignalrTargetHub) and call a SendMessage method on it?
Are there performance ramifications for either?
[Target("Signalr")]
public class SignalrTarget:TargetWithLayout
{
public SignalR.IConnectionManager ConnectionManager { get; set; }
public SignalrTarget()
{
ConnectionManager = AspNetHost.DependencyResolver.Resolve<IConnectionManager>();
}
protected override void Write(NLog.LogEventInfo logEvent)
{
dynamic clients = GetClients();
var logEventObject = new
{
Message = this.Layout.Render(logEvent),
Level = logEvent.Level.Name,
TimeStamp = logEvent.TimeStamp.ToString("yyyy-MM-dd HH:mm:ss.fff")
};
clients.onLoggedEvent(logEventObject);
}
private dynamic GetClients()
{
return ConnectionManager.GetClients<SignalrTargetHub>();
}
}
I ended up with the basic the same basic structure that I started with. Just a few tweaks to get the information I needed.
Added exception details.
Html encoded the final message.
[Target("Signalr")]
public class SignalrTarget:TargetWithLayout
{
protected override void Write(NLog.LogEventInfo logEvent)
{
var sb = new System.Text.StringBuilder();
sb.Append(this.Layout.Render(logEvent));
if (logEvent.Exception != null)
sb.AppendLine().Append(logEvent.Exception.ToString());
var message = HttpUtility.HtmlEncode(sb.ToString());
var logEventObject = new
{
Message = message,
Logger = logEvent.LoggerName,
Level = logEvent.Level.Name,
TimeStamp = logEvent.TimeStamp.ToString("HH:mm:ss.fff")
};
GetClients().onLoggedEvent(logEventObject);
}
private dynamic GetClients()
{
return AspNetHost.DependencyResolver.Resolve<IConnectionManager>().GetClients<SignalrTargetHub>();
}
}
In my simple testing it's working well. Still remains to be seen if this adds any significant load when under stress.