am using ABP to build my project
I have a module to generate big size files using background worker, and after each successful file generated I need to send notification, but is not working !
I've put the background job in the core project and the queue in the engine project,
the DB notification tables are updated successfully (new record inserted so the pull notification will work fine !), but the browser doesn't receive the notification (so I can inform him that his file is ready), but there is no errors and no any notification send to the browser.
here is the worker class:
public class GeneratedFileWorker : BackgroundWorkerBase, ISingletonDependency
{
.
.
.
[UnitOfWork]
[AutomaticRetry(Attempts = 0)]
public override async System.Threading.Tasks.Task ExecuteAsync()
{
var notificationData = new NotificationData();
notificationData["URL"] = "app/main/data/generatedfiles";
using (AbpSession.Use(TenantConsts.DefaultTenantId, TenantConsts.UserServiceId))
{
GetDownloadArticleInput getDownloadArticleInput = new GetDownloadArticleInput();
if (pendingRequest is not null)
{
var entityType = _lookupItemManager.Get(pendingRequest.EntityTypeId).Code;
dynamic Args = JsonConvert.DeserializeObject<GetDownloadArticleInput>(String.Empty);
switch (entityType)
{
case "Article":
Args = JsonConvert.DeserializeObject<GetDownloadArticleInput>(pendingRequest.ExtensionData);
break;
case "ArticlesList":
Args = JsonConvert.DeserializeObject<GetDownloadArticlesInput>(pendingRequest.ExtensionData);
break;
};
GeneratedFile generatedFileDto = new GeneratedFile();
try
{
generatedFileDto = await _generateFile.Generate(Args);
await _appNotifier.SendMessageAsync(new UserIdentifier(1, pendingRequest.CreatorUserId.Value),string.Format(_LocalizationSource.GetString("GeneratedFile.fileIsNotready"), _lookupItemManager.GetTitle(pendingRequest.EntityTypeId)), notificationData, NotificationSeverity.Error);
else
await _appNotifier.SendMessageAsync(new UserIdentifier(1, pendingRequest.CreatorUserId.Value), string.Format(_LocalizationSource.GetString("GeneratedFile.fileIsready"), _lookupItemManager.GetTitle(pendingRequest.EntityTypeId)), notificationData, NotificationSeverity.Success);
}
catch (Exception ex)
{
pendingRequest.CurrentStateId = _lookupItemManager.GetByCode(LookupCategories.GeneratedFileStatus, "Failed").Id;
pendingRequest.OperationResult = ex.ToString();
await _generatedFileRepository.UpdateAsync(pendingRequest);
await _appNotifier.SendMessageAsync(new UserIdentifier(1, pendingRequest.CreatorUserId.Value), string.Format(_LocalizationSource.GetString("GeneratedFile.fileIsNotready"), _lookupItemManager.GetTitle(pendingRequest.EntityTypeId)), notificationData, NotificationSeverity.Error);
}
}
}
}
I have 2 cases here:
first one working when I define the queue in the host project, and
second one not working when I define the queue in the engine project
Related
Greeting,
I'm currently facing a problem that my coroutine can't start. This is the first time I facing this issues and I can't find a proper solution online. Much appreciated if anyone can point me to the right direction to solve this issue.
Here are the code.
path_reference.GetDownloadUrlAsync().ContinueWith((Task<Uri> task) => {
if (!task.IsFaulted && !task.IsCanceled)
{
Debug.Log("Download URL: " + task.Result);
StartCoroutine(DownloadStuff(task.Result));
}
else
{
Debug.Log(task.Exception.ToString());
}
});
}
IEnumerator DownloadStuff(Uri uri)
{
Debug.Log("Start Download");
using (var www = UnityWebRequestTexture.GetTexture(uri))
{
yield return www.SendWebRequest();
if (www.isNetworkError || www.isHttpError)
{
Debug.Log(www.error);
}
else
{
var texture = DownloadHandlerTexture.GetContent(www);
//Texture2D texture = new Texture2D(1, 1);
//if you need sprite for SpriteRenderer or Image
Sprite sprite = Sprite.Create(texture, new Rect(0.0f, 0.0f, texture.width,
texture.height), new Vector2(0.5f, 0.5f), 100.0f);
Debug.Log("Finished downloading!");
}
Debug.Log(www.downloadProgress);
}
}'
The task returned by Firebase probably finishes execution on a thread other than the main thread, and Unity coroutines can only run on the main thread.
Unity's support of multithreading and async is pretty spotty, including "eating" some errors if the continuations of those errors would execute on another thread other than the main thread.
To fix this, you need to change the function that starts your coroutine:
try {
// Important: ConfigureAwait(true) ensures the code after this will run in the
// same thread as the code before (which is the main thread!)
var url = await path_reference.GetDownloadUrlAsync().ConfigureAwait(true);
StartCoroutine(DownloadStuff(url));
} catch (Exception ex) {
// Tip: when logging errors, use LogException and pass the whole exception,
// that way you will get pretty links to the error line in the whole stack trace.
Debug.LogException(ex);
}
As an aside, I usually have a few extension methods on all my projects to deal with that while staying in async-world instead of coroutine-world (because at least with async I can catch errors and not just "halt and catch fire" like Unity's coroutines)
The main ones are:
public static Task ToTask(this YieldInstruction self, MonoBehaviour owner) {
var source = new TaskCompletionSource<object>();
IEnumerable Routine() {
yield return self;
source.SetResult(null);
}
return source.Task;
}
private static Task SendAsync(this UnityWebRequest self, MonoBehaviour owner) {
var source = new TaskCompletionSource<object>();
await self.SendWebRequest().ToTask(owner);
if (
self.isHttpError
|| self.isNetworkError
) {
source.SetException(new Exception(request.error));
yield break;
}
source.SetResult(null);
}
Which you can use like this, inside a MonoBehaviour:
await new WaitForSeconds(0.2f).ToTask(this);
UnityWebRequest request = /* etc */;
await request.SendAsync(this);
var texture = DownloadHandlerTexture.GetContent(request);
Note that these methods do not require ConfigureAwait, since their SetResult/SetException invocations are ran from Unity-provided coroutine continuations.
I am using Tessaract's Xamarin Forms Nuget(https://github.com/halkar/Tesseract.Xamarin), and am trying to scan a picture taken by the Android Device. This is the code that I am using:
private async System.Threading.Tasks.Task<string> OCRAsync(byte[] bytes)
{
TesseractApi api;
api = new TesseractApi(this, AssetsDeployment.OncePerInitialization);
await api.Init("bul");
await api.SetImage(bytes);
var detectedText = api.Results(PageIteratorLevel.Block);
result = string.Empty;
if (detectedText != null)
{
foreach (var annotation in detectedText)
{
result = FindWordInDictionary(annotation.Text);
}
}
return result;
}
The method is called from a synchronized method like this:
var task = OCRAsync(data);
result = task.Result;
Whenever the compiler gets to "await api.Init("bul");" the app freezes indefinitely. Do you know what may cause this problem? Thank you.
The problem was that I needed to give a file location in the .init function:
await api.Init(pathToDataFile, "bul");
I am currently attemping to build a custom Editor tool for Unity that utilizes the Firebase Realtime Database. This tool would allow someone to right-click on a scene asset in the inspector and select to 'lock' or 'unlock' the scene. Within our Firebase Database, this locking is represented by a dictionary, with each scene name as a key and each value being either "locked" or "unlocked". This funcitonality will be expanded later, but for now, I'm just trying to get things set up so that I can actually connect to and use the Firebase Realtime Database.
I had looked at the Firebase Quickstart Unity project for the Realtime Database (the one that functions like a leaderboard) and saw that it worked fine. I could replace the database URL in the project with the URL for my app's database, and when I entered in values, they appeared inside my realtime database.
So, I based the code for my custom editor script on the code from the quickstart. In fact, I copy-pasted most of it. I will post the script itself, and then describe the errors I receive, as well as the lines that give the errors:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEditor;
using Firebase;
using Firebase.Unity.Editor;
using Firebase.Database;
[CustomEditor(typeof(SceneAsset))]
[ExecuteInEditMode]
public class SceneLockingEditor : Editor
{
static string sceneName;
DependencyStatus dependencyStatus = DependencyStatus.UnavailableOther;
protected virtual void OnEnable()
{
Debug.Log("OnEnable Called");
sceneName = target.name;
FirebaseApp.CheckAndFixDependenciesAsync().ContinueWith(task => {
dependencyStatus = task.Result;
if (dependencyStatus == DependencyStatus.Available)
{
InitializeFirebase();
}
else
{
Debug.LogError(
"Could not resolve all Firebase dependencies: " + dependencyStatus);
}
});
}
// Initialize the Firebase database:
protected virtual void InitializeFirebase()
{
Debug.Log("Initializing Firebase");
FirebaseApp app = FirebaseApp.DefaultInstance;
app.SetEditorDatabaseUrl(CENSORING MY DATABASE SORRY);
if (app.Options.DatabaseUrl != null) app.SetEditorDatabaseUrl(app.Options.DatabaseUrl);
}
static TransactionResult SceneLockTransaction(MutableData mutableData)
{
List<object> sceneLocks = mutableData.Value as List<object>;
if (sceneLocks == null)
{
sceneLocks = new List<object>();
}
if(mutableData.ChildrenCount > 0)
{
//Look at every child in the scene locks directory.
foreach (var child in sceneLocks)
{
Debug.Log("Checking next child.");
if (!(child is Dictionary<string, object>))
continue;
//If we find the scene we're looking for...
Debug.Log("Checking if the scene has the name we want");
foreach(string key in ((Dictionary<string, object>)child).Keys)
{
Debug.Log("Key: " + key);
}
if(((Dictionary<string, object>)child).ContainsKey(sceneName))
{
string childLockStatus = (string)((Dictionary<string, object>)child)["lockStatus"];
//If the scene is already locked, just abort.
if (childLockStatus == "locked")
{
Debug.Log("Scene is already locked. Abort.");
return TransactionResult.Abort();
}
else
{
Debug.Log("Scene existed in the database and was not locked. Locking it.");
// If the scene existed in the database but was not locked, we will lock it.
((Dictionary<string, object>)child)[sceneName] = "locked";
// You must set the Value to indicate data at that location has changed.
mutableData.Value = sceneLocks;
return TransactionResult.Success(mutableData);
}
}
}
}
Debug.Log("Scene did not exist in the database. Adding it as locked.");
// If the scene didn't exist in the database before, we will add it as locked.
Dictionary<string, object> newSceneLock = new Dictionary<string, object>();
newSceneLock[sceneName] = "locked";
sceneLocks.Add(newSceneLock);
// You must set the Value to indicate data at that location has changed.
mutableData.Value = sceneLocks;
return TransactionResult.Success(mutableData);
}
static TransactionResult SceneUnlockTransaction(MutableData mutableData)
{
List<object> sceneLocks = mutableData.Value as List<object>;
if (sceneLocks == null)
{
sceneLocks = new List<object>();
}
if (mutableData.ChildrenCount > 0)
{
//Look at every child in the scene locks directory.
foreach (var child in sceneLocks)
{
Debug.Log("Checking next child.");
if (!(child is Dictionary<string, object>))
continue;
//If we find the scene we're looking for...
Debug.Log("Checking if the scene has the name we want");
foreach (string key in ((Dictionary<string, object>)child).Keys)
{
Debug.Log("Key: " + key);
}
if (((Dictionary<string, object>)child).ContainsKey(sceneName))
{
string childLockStatus = (string)((Dictionary<string, object>)child)["lockStatus"];
//If the scene is already locked, just abort.
if (childLockStatus == "unlocked")
{
Debug.Log("Scene is already unlocked. Abort.");
return TransactionResult.Abort();
}
else
{
Debug.Log("Scene existed in the database and was locked. Unlocking it.");
// If the scene existed in the database but was not locked, we will lock it.
((Dictionary<string, object>)child)[sceneName] = "unlocked";
// You must set the Value to indicate data at that location has changed.
mutableData.Value = sceneLocks;
return TransactionResult.Success(mutableData);
}
}
}
}
Debug.Log("Scene did not exist in the database. Adding it as unlocked.");
// If the scene didn't exist in the database before, we will add it as locked.
Dictionary<string, object> newSceneLock = new Dictionary<string, object>();
newSceneLock[sceneName] = "unlocked";
sceneLocks.Add(newSceneLock);
// You must set the Value to indicate data at that location has changed.
mutableData.Value = sceneLocks;
return TransactionResult.Success(mutableData);
}
static public void AddSceneLock()
{
Debug.Log("Attempting to add scene lock to database.");
DatabaseReference reference = FirebaseDatabase.DefaultInstance.GetReference("SceneLocks");
Debug.Log("Running Transaction...");
// Use a transaction to ensure that we do not encounter issues with
// simultaneous updates that otherwise might create more than MaxScores top scores.
reference.RunTransaction(SceneLockTransaction)
.ContinueWith(task => {
if (task.Exception != null)
{
Debug.Log(task.Exception.ToString());
}
else if (task.IsCompleted)
{
Debug.Log("Transaction complete.");
}
});
}
static public void RemoveSceneLock()
{
Debug.Log("Attempting to add scene lock to database.");
DatabaseReference reference = FirebaseDatabase.DefaultInstance.GetReference("SceneLocks");
Debug.Log("Running Transaction...");
// Use a transaction to ensure that we do not encounter issues with
// simultaneous updates that otherwise might create more than MaxScores top scores.
reference.RunTransaction(SceneUnlockTransaction)
.ContinueWith(task => {
if (task.Exception != null)
{
Debug.Log(task.Exception.ToString());
}
else if (task.IsCompleted)
{
Debug.Log("Transaction complete.");
}
});
}
[MenuItem("CONTEXT/SceneAsset/Lock Scene", false, 0)]
public static void LockScene()
{
Debug.Log("LockScene Called for scene " + sceneName + ".");
AddSceneLock();
}
[MenuItem("CONTEXT/SceneAsset/Unlock Scene", false, 0)]
public static void UnlockScene()
{
Debug.Log("UnlockScene Called for scene " + sceneName + ".");
RemoveSceneLock();
}
}
The errors always come from this line:
FirebaseDatabase.DefaultInstance.GetReference("SceneLocks");
Any line that has to do with "FirebaseDatabase.DefaultInstance" will throw one of the following two errors
Error 1:
InvalidOperationException: SyncContext not initialized.
Firebase.Unity.UnitySynchronizationContext.get_Instance ()
Firebase.Platform.PlatformInformation.get_SynchronizationContext ()
Firebase.FirebaseApp.get_ThreadSynchronizationContext ()
Firebase.Database.DotNet.DotNetPlatform+SynchronizationContextTarget..ctor ()
Firebase.Database.DotNet.DotNetPlatform.NewEventTarget (Firebase.Database.Internal.Core.Context c)
Firebase.Database.Internal.Core.Context.EnsureEventTarget ()
Firebase.Database.Internal.Core.Context.InitServices ()
Firebase.Database.Internal.Core.Context.Freeze ()
Firebase.Database.Internal.Core.RepoManager.CreateLocalRepo (Firebase.Database.Internal.Core.Context ctx, Firebase.Database.Internal.Core.RepoInfo info, Firebase.Database.FirebaseDatabase firebaseDatabase)
Firebase.Database.Internal.Core.RepoManager.CreateRepo (Firebase.Database.Internal.Core.Context ctx, Firebase.Database.Internal.Core.RepoInfo info, Firebase.Database.FirebaseDatabase firebaseDatabase)
Firebase.Database.FirebaseDatabase.EnsureRepo ()
Firebase.Database.FirebaseDatabase.get_RootReference ()
SceneLockingEditor.OnInspectorGUI () (at Assets/Bitloft/SCRIPTS/Editor/SceneLockingEditor.cs:37)
UnityEditor.InspectorWindow.DrawEditor (UnityEditor.Editor[] editors, Int32 editorIndex, Boolean rebuildOptimizedGUIBlock, System.Boolean& showImportedObjectBarNext, UnityEngine.Rect& importedObjectBarRect) (at C:/buildslave/unity/build/Editor/Mono/Inspector/InspectorWindow.cs:1242)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)
Error 2:
Exception: Custom Run loops are not supported!
Firebase.Database.Internal.Core.Context.GetExecutorService ()
Firebase.Database.Internal.Core.Context.GetConnectionContext ()
Firebase.Database.Internal.Core.Context.NewPersistentConnection (Firebase.Database.Internal.Connection.HostInfo info, IDelegate delegate_)
Firebase.Database.Internal.Core.Repo..ctor (Firebase.Database.Internal.Core.RepoInfo repoInfo, Firebase.Database.Internal.Core.Context ctx, Firebase.Database.FirebaseDatabase firebaseDatabase)
Firebase.Database.Internal.Core.RepoManager.CreateLocalRepo (Firebase.Database.Internal.Core.Context ctx, Firebase.Database.Internal.Core.RepoInfo info, Firebase.Database.FirebaseDatabase firebaseDatabase)
Firebase.Database.Internal.Core.RepoManager.CreateRepo (Firebase.Database.Internal.Core.Context ctx, Firebase.Database.Internal.Core.RepoInfo info, Firebase.Database.FirebaseDatabase firebaseDatabase)
Firebase.Database.FirebaseDatabase.EnsureRepo ()
Firebase.Database.FirebaseDatabase.get_RootReference ()
SceneLockingEditor.OnInspectorGUI () (at Assets/Bitloft/SCRIPTS/Editor/SceneLockingEditor.cs:37)
UnityEditor.InspectorWindow.DrawEditor (UnityEditor.Editor[] editors, Int32 editorIndex, Boolean rebuildOptimizedGUIBlock, System.Boolean& showImportedObjectBarNext, UnityEngine.Rect& importedObjectBarRect) (at C:/buildslave/unity/build/Editor/Mono/Inspector/InspectorWindow.cs:1242)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)
It's always one error or the other, and I can't determine what causes one error to appear rather than the other. Both errors stop whatever operation I'm trying to do on the database, which means I can't interact with my database at all.
I've taken a look at the quickstart projects and watched some videos of people setting up Firebase to work with their projects, and I can't seem to determine what I have messed up during the process. I have imported my google-services.json into the unity project. The quickstart projects worked just fine interacting with my database. It's just this particular script that won't work. I cannot find any mention of these two errors anywhere on Google. I even contacted the official Firebase support and they couldn't give me any advice on what the errors mean or what could be causing them.
I considered one problem might be in my initialization function. Instead of doing:
FirebaseApp app = FirebaseApp.DefaultInstance;
I figured that maybe I am supposed to use FirebaseApp.Create() with a custom name passed in, but that resulted in the same errors being thrown on the same line. I am at a loss for how to proceed with this problem. I don't know of anyone else who has had these particular errors, and I've done very much experimentation with different ways to access the database over the past several days. If anybody has an idea of what I am doing wrong here, or what causes these errors (and, how to fix them), I would really appreciate it.
At first you should initialize firebase with new instance of FirebaseApp with unique name. I do it like this:
FirebaseApp firebaseApp = FirebaseApp.Create(
FirebaseApp.DefaultInstance.Options,
"FIREBASE_EDITOR");
The second is setup references (DatabaseReference, StorageReference etc.) with this firebaseApp instance and use it only after FirebaseApp.CheckAndFixDependenciesAsync()
Overall code will look like this:
public static void Initialize(bool isEditor = false)
{
if (isEditor)
{
FirebaseApp firebaseApp = FirebaseApp.Create(
FirebaseApp.DefaultInstance.Options,
"FIREBASE_EDITOR");
firebaseApp.SetEditorDatabaseUrl("https://project.firebaseio.com/");
FirebaseApp.CheckAndFixDependenciesAsync().ContinueWith(task =>
{
if (task.Result == DependencyStatus.Available)
{
database = FirebaseDatabase.GetInstance(firebaseApp).RootReference;
storage = FirebaseStorage.GetInstance(firebaseApp).RootReference;
auth = FirebaseAuth.GetAuth(firebaseApp);
}
else
{
Debug.LogError(
"Could not resolve all Firebase dependencies: " + task.Result);
}
});
}
else
{
FirebaseApp.DefaultInstance.SetEditorDatabaseUrl("https://project.firebaseio.com/");
database = FirebaseDatabase.DefaultInstance.RootReference;
storage = FirebaseStorage.DefaultInstance.RootReference;
auth = FirebaseAuth.DefaultInstance;
}
IsInitialized = true;
}
I had the same errors. I spent several hours solving this and it worked for me
I recently encountering an annoying bug that only happen in 1 out of our 3 environments (Amazon EC2 to be specific). When I send a request to the Cloud API to receive tags about the picture. The function crashes but I don't see any exception caught by the try catch. The function works fine until June 1st but I don't know why it doesn't anymore (other 2 environments work just fine).
Here are the code:
try {
GoogleCredentials cred = GoogleCredentials.fromStream(new FileInputStream(coreConfig.googleCreds()));
log.error("GoogleCredentials cred = GoogleCredentials.fromStream(new FileInputStream(coreConfig.googleCreds()));");
ImageAnnotatorSettings imageAnnotatorSettings = ImageAnnotatorSettings.newBuilder()
.setCredentialsProvider(FixedCredentialsProvider.create(cred))
.build();
ImageAnnotatorClient vision = ImageAnnotatorClient.create(imageAnnotatorSettings);
log.error("ImageAnnotatorClient vision = ImageAnnotatorClient.create(imageAnnotatorSettings);");
byte[] data = IOUtils.toByteArray(is);
ByteString bs = ByteString.copyFrom(data);
// Builds the image annotation request
List<AnnotateImageRequest> requests = new ArrayList<>();
log.error("ByteString bs = ByteString.copyFrom(data);");
Image img = Image.newBuilder().setContent(bs).build();
log.error(" Image img = Image.newBuilder().setContent(bs).build();");
Feature feat = Feature.newBuilder().setType(Type.LABEL_DETECTION).build();
log.error("Feature feat = Feature.newBuilder().setType(Type.LABEL_DETECTION).build();");
AnnotateImageRequest request = AnnotateImageRequest.newBuilder()
.addFeatures(feat)
.setImage(img)
.build();
requests.add(request);
log.error("requests.add(request);");
// Performs label detection on the image file
BatchAnnotateImagesResponse response = vision.batchAnnotateImages(requests);
log.error("BatchAnnotateImagesResponse response = vision.batchAnnotateImages(requests);");
List<AnnotateImageResponse> responses = response.getResponsesList();
log.error("List<AnnotateImageResponse> responses = response.getResponsesList();");
for (AnnotateImageResponse res : responses) {
if (res.hasError()) {
throw new ServiceException(ServiceStatus.BAD_REQUEST, res.getError().getMessage());
}
for (EntityAnnotation annotation : res.getLabelAnnotationsList()) {
tags.append("===" + annotation.getDescription().replaceAll("\\s+",""));
log.error("tags.append(\"===\" + annotation.getDescription().replaceAll(\"\\\\s+\",\"\"));");
}
}
return tags;
}catch(Exception e) {
e.printStackTrace();
log.error(e.getMessage());
return null;
// throw new ServiceException(ServiceStatus.BAD_REQUEST, e.getMessage());
}
Here are the details about it:
It seems like an old version of guava (in this case 17.0-jdk) caused this crash.
You still have to remove the old version not only from the pom.xml but also in the lib folder of the .war file.
I have a ASP.Net C# 4.0 Web Application
I need to Add a scanning feature for my users.
This is what I want to achieve
On my web application
user clicks on a button
opens a window with preview of document in Scanning device attached to the client system
User confirms the Scan
this will save the Scanned document in jpg/pdf format on the server
then do the OCR on document
Can any one suggest a way to achieve this.
I read about this https://www.leadtools.com/sdk/engine/imaging not sure how much this can work. Can any one suggest a best way to get this done.
Thanks
update
tried leadtools from https://www.leadtools.com/support/forum/posts/m28036-Re--Scan-and-Upload-v16--NET-with-Caspol-exe-deployment as LEAD Support suggested but it is missing references not sure where and how to get those references
HaBo,
This is LEAD support. Since you mentioned our LEADTOOLS toolkit, the answer to your question is yes. Our toolkit can be used to implement either of the 2 approaches mentioned by tgolisch.
For the click-once approach, you simply use our Windows Forms controls that contain Twain support and package your application for ClickOnce deployment. This is done, for example, in this demo project:
LEADTOOLS ClickOnce Demos
For the custom control approach, see the example code projects on our forums that perform Scan and Upload
Solution is here:
In ASP.Net/Core Project you send message to call winform project:
var start = function () {
var i = 0;
var wsImpl = window.WebSocket || window.MozWebSocket;
window.ws = new wsImpl('ws://localhost:8181/');
ws.onmessage = function (e) {
$('#submit').hide();
$('#scanBtn').hide();
$('.loader').show();
if (typeof e.data === "string") {
//IF Received Data is String
}
else if (e.data instanceof ArrayBuffer) {
//IF Received Data is ArrayBuffer
}
else if (e.data instanceof Blob) {
i++;
var f = e.data;
f.name = "File" + i;
storedFiles.push(f);
formdata.append(f.name, f);
var reader = new FileReader();
reader.onload = function (e) {
var html = "<div class=\"col-sm-2 text-center\"
style=\"border: 1px solid black; margin-left: 2px;\"><img
height=\"200px\" width=\"200px\" src=\"" + e.target.result + "\"
data-file='" + f.name + "' class='selFile' title='Click to
remove'><br/>" + i + "</div>";
selDiv.append(html);
$('#submit').show();
$('#scanBtn').show();
$('.loader').hide();
}
reader.readAsDataURL(f);
}
};
ws.onopen = function () {
//Do whatever u want when connected succesfully
};
ws.onclose = function () {
$('.dalert').modal('show');
};
}
window.onload = start;
function scanImage() {
ws.send("1100");
};
https://javascript.info/websocket
In Winforms Project you scan document and send graphic data back to Asp.Net/Core project:
public partial class Form1 : Form
{
ImageCodecInfo _tiffCodecInfo;
TwainSession _twain;
bool _stopScan;
bool _loadingCaps;
List allSockets;
WebSocketServer server;
public Form1()
{
InitializeComponent();
if (NTwain.PlatformInfo.Current.IsApp64Bit)
{
Text = Text + " (64bit)";
}
else
{
Text = Text + " (32bit)";
}
foreach (var enc in ImageCodecInfo.GetImageEncoders())
{
if (enc.MimeType == "image/tiff") { _tiffCodecInfo = enc; break; }
}
this.WindowState = FormWindowState.Minimized;
this.ShowInTaskbar = false;
allSockets = new List<IWebSocketConnection>();
server = new WebSocketServer("ws://0.0.0.0:8181");
server.Start(socket =>
{
socket.OnOpen = () =>
{
Console.WriteLine("Open!");
allSockets.Add(socket);
};
socket.OnClose = () =>
{
Console.WriteLine("Close!");
allSockets.Remove(socket);
};
socket.OnMessage = message =>
{
if (message == "1100")
{
this.Invoke(new Action(()=> {
this.WindowState = FormWindowState.Normal;
}));
}
};
});
}
Link to project.
https://github.com/mgriit/ScanAppForWeb
You can remake this project, as you want.
Web browsers don't have permissions to use system devices like this(major security issue). There are 2 common ways of getting around this:
Make a custom control to run in your browser (flash, silverlight, java applet).
Make a "click-once deployment app" that a user launches from your page.
Both approaches would send the data back to your server via web
services or WCF, etc.