Search Results

Search found 35940 results on 1438 pages for 'console app'.

Page 85/1438 | < Previous Page | 81 82 83 84 85 86 87 88 89 90 91 92  | Next Page >

  • /SUBSYSTEM:Windows program will not write to command line

    - by user144182
    I have a mixed mode C++-CLI program in Visual Studio 2005 that is set to use the /SUBSYSTEM:Windows. Generally speaking it is a graphical application that is launched from its shortcut or through the filetype registered to it. However, there is a rare occasion where a user will want to run it from the command line with arguments. I can access the arguments just fine, its when it comes to writing to the console, in response to the program being launched from the command line with arguments, where I don't see Console::WriteLine having any effect. What am I doing wrong?

    Read the article

  • Open a PDF file in an external app on iPad

    - by Yuji
    I'd like to make my app to open a specified PDF by an external app of the user's choice on the iPad. How can I do that? Or, is there any open-source PDF reader framework available so that I can put it into my app? My situation in more detail: I'm thinking of porting to the iPad from OS X / rewriting from scratch for the iPad an app which manages lots of PDFs (journal articles, etc.), but I don't want to write the PDF reader part, because there are many good ones already out there; I don't want to reinvent the wheels. (You might say you shouldn't reinvent pdf management apps, but I'd like to make one as a front end to SPIRES, and there isn't one so far.) As the app would be a front end to a serious reading activity, UIWebView's pdf capability is not enough. Also, users of my app would have various preferences which app to use. That's the background behind my question. Thanks in advance!

    Read the article

  • Received memory warning and app crashes - iphone

    - by Anand Gautam
    I am creating an app using ARC but my app is crashing due to Received memory warning. The App is working fine in simulator. But in case of iphone device, If i run the app for few minutes then on doing anything, the app crashes straightaway. I have checked my app by xcode instrument. My app folder size is 6 MB but all memory allocation is showing 63 MB on xcode instrument. Because of this reason, presentViewController-Animated-Completion is getting slow during navigation. Does anyone have any solution why this is happening?

    Read the article

  • Implementing Multitasking on an iPhone/iOS4 Web App

    - by Peter Watts
    I am looking to build a web app that implements background audio and fast app switching. These features work out of the box, when run as regular Safari web pages, but as soon as you add the web-app-capable tag, and try to run in full screen mode, this functionality breaks. I did some testing and even the most basic web app will reload every time when you switch back to it. And seeing as it's a web app, we can't exactly implement the multitasking API. Has anyone found a work around? This isn't a deal-breaker, as you can just avoid full screen mode, but then you also lose the ability to use your own icon in the app switch tray. Perhaps this explains a lack of full screen mode in YouTube's new web app....

    Read the article

  • Converting a navbar to a tabbar app

    - by Nick
    Hey guys, I was wondering how to convert a NavigationController style app into a TabBarcontroller style app. I changed my mainwindow to not contain a navigationcontroller anymore (but a tabbarcontroller instead) and my delegate also appropiatly, but when I launch the app something still thinks I want a navigationController: Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[ setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key navigationController.' Stack trace: #0 0x020fa004 in ___TERMINATING_DUE_TO_UNCAUGHT_EXCEPTION___ #1 0x96fc0509 in objc_exception_throw #2 0x020ee1c1 in -[NSException raise] #3 0x000d8a78 in _NSSetUsingKeyValueSetter #4 0x000d84c5 in -[NSObject(NSKeyValueCoding) setValue:forKey:] #5 0x004fb4c8 in -[UIRuntimeOutletConnection connect] #6 0x020af92f in -[NSArray makeObjectsPerformSelector:] #7 0x004f9f7f in -[UINib instantiateWithOptions:owner:loadingResourcesFromBundle:] #8 0x004fbfcb in -[NSBundle(NSBundleAdditions) loadNibNamed:owner:options:] #9 0x0033b0a6 in -[UIApplication _loadMainNibFile] #10 0x0034482a in -[UIApplication _runWithURL:sourceBundleID:] #11 0x00341b88 in -[UIApplication handleEvent:withNewEvent:] #12 0x0033d6d3 in -[UIApplication sendEvent:] #13 0x003440b5 in _UIApplicationHandleEvent #14 0x0265aed1 in PurpleEventCallback #15 0x02092b80 in CFRunLoopRunSpecific #16 0x02091c48 in CFRunLoopRunInMode #17 0x0033be69 in -[UIApplication _run] #18 0x00345003 in UIApplicationMain #19 0x00002ec8 in main at main.m:14 Where can I specify the app is a tabbarcontrolled app, instead of a navigationbarcontrolled app? Thanks in advance,

    Read the article

  • What are some good ways to promote my Android application?

    - by Bryan Denny
    I'm a new Android developer and I just released a free, open source tipping calculator app called Tippy Tipper. I created this app to get myself familiar with Android and to hopefully provide a good example app for other new developers to look at. Now that I've overcome the challenges of learning how to program, test and release my Android app, I've come across a new challenge: marketing! What are some good ways to promote my app to the Android community? Can anyone with some experience talk about how they did this successfully with their own app?

    Read the article

  • Python - react to custom keyboard interrupt

    - by flixic
    Hello. I am writing python chatbot that displays output through console. Every half second it asks server for updates, and responds to message. In the console I can see chat log. This is sufficient in most cases, however, sometimes I want to interrupt normal workflow and write custom chat answer myself. I would love to be able to press a button (or combination) that would switch to "custom reply mode". What is the best way to do that, or achieve similar result? Thanks a lot!

    Read the article

  • Android -- How to post app rating/comments to Market from within app?

    - by borg17of20
    Hello all, This is a simple question. Is there a way to allow users to enter in a comment and or rating for my app from directly within my app and have that data posted back to the Android Market? If so, what would the code for that look like if I used an EditText view to allow user input? If not, then is my only other option directly linking to my app in the Market (i.e. the user clicks the link in my app, or a button, and the Market app launches with my app page displayed)? For example: view.setOnClickListener( new OnClickListener(){ public void onClick(View v) { startActivity( new Intent( Intent.ACTION_VIEW, Uri.parse("market://details?id=packagename") ) ); } } *where "packagename" is replaced by my app's package name from the manifest. Thanks.

    Read the article

  • Store Observer not being called always

    - by Nixarn
    Has anyone else here experienced problems with their Store Observer class not being called always when the user for instance cancels a request (or purchases something) We just had our update that brought in app purchases go live last night, and before that we had obviously tested everything tons of times against the Sandbox and everything was working fine. Now however, when the update went live in a real environment we keep getting issues with the store. For instance, in a freshly booted iPhone / iPod, the first time you run the app, if you then try to make a purchase and then immediately cancel it from the first dialog, it seems as if the callback for the cancel is not getting called. If you then restart the app it seems as if it always works after that, or at least. Same thing with other callbacks, seems as if our store observer isn't listening as the callbacks aren't being registered on the phone. One example of this is if you purchase something, then nothing will happen (if this is the first time the app is launched at least). You get the purchase successful dialog from the app store but it seems as if our own code isn't called. If you then quit the app and restart it the callback gets called. Same problem happens if you for instance try to start a request to download all previous purchases and then immediately cancel it as the first dialog pops up, if you do that then the callback for a failed restore is not called, until you then restart the app and try it again, then it always seems to work. The way we have implemented our store observer is by creating a custom class that's implements the SKPaymentTransactionObserver interface. @interface StoreObserver : NSObject<SKPaymentTransactionObserver> In the class we have implemented the following methods: - (void)paymentQueue:(SKPaymentQueue *)queue updatedTransactions:(NSArray *)transactions - (void)paymentQueueRestoreCompletedTransactionsFinished:(SKPaymentQueue *)queue - (void)paymentQueue:(SKPaymentQueue *)queue restoreCompletedTransactionsFailedWithError:(NSError *)error The way our restore process works is that if you tap on the button that allows you to download all we simply run the restoreCompletedTransactions code as follows: [[SKPaymentQueue defaultQueue] restoreCompletedTransactions]; However, the callback, restoreCompletedTransactionsFailedWithError, which has been implemented in the store observer, does not always get called when we try to cancel the request. This happens when you boot the iPhone / iPod and try this for the first time. If you after that restart the app everything works fine. The StoreObserver class is created when our app is launched, just by running the following code: pStoreObserver = [[StoreObserver alloc] init]; [[SKPaymentQueue defaultQueue] addTransactionObserver:pStoreObserver]; Has anyone else had any similar experiences? Or does anyone have any suggestions on how to solve this? As I said, in the sandbox environment everything was working fine, no issues whatsoever, but now once it's gone live we're experiencing these.

    Read the article

  • How to tell if a user updated my app or installed a new one

    - by user310318
    I need a way to tell if the app being used by a user is a fresh new install (new user), or was a pre-existing user who updated. The previous app version did not track UDID's, and didn't save anything (it just ran as a simple app). Is there a way for an update to tell if the user previously installed the app? Even if that app didn't save anything into the documents folder, and the app didnt communicate with a server (UDID post)? (id like to be able to offer bonus features to my existing loyal users who had already installed the original app and updated) thanks!!

    Read the article

  • Launching a Facebook page from an iPhone app via QR code

    - by user1655186
    I'm trying to create a QR code that launches a Facebook page from the app, rather than the browser on both Android and iOS. Creating the code with fb://page/<page id>, works perfectly on an Android. This was also supposed to work with iOS's Facebook app, but I think since Facebook updated their app recently from a HTML5 version to a fully native iOS app, that functionality has stopped working. It indeed opens the Facebook app, but it does not go to the page. Has anyone else seen this happen since the app was updated a few weeks ago? And what string would I have to use to create a working QR Code for iOS's Facebook app?

    Read the article

  • Can I submit iPhone applications with same Icon.png but differnt bundle name

    - by AJ
    Can some one tell me if it is possible to submit two different iphone applications which has same Icon.png but have a different bundle name? I am working on a travel guide app that is targeted for different cities. I want the users of different cities to download the app as per their cities. So I want to submit different apps for different cities(3 in my case). User can also purchase any of these cities through in-app purchase. In that case the new purchased city would be unlocked in the app. Here is my thing. I want the same icon for all the three apps. I can do away with different names for app store and bundle(home screen icon name). But I am not sure if apple would approve/reject this app. Can someone enhance this blur picture I have?

    Read the article

  • App crashing on open on Motorola Backflip only

    - by anakin78z
    I have recently published my second app on the Android Market. I've gotten a few e-mails about the app crashing on open, and all users were using the Motorola Backflip. It seems to work fine on all other devices. The app shows the background image, but crashes right after that. Is there something different I have to do when coding for that device? The strange thing is that it is very similar to my first app, which seems to work just fine for them. The major difference is that my second app is a paid app, and uses Android Licence Verification. My implementation should catch any license errors though, and I've tested this on my device. Users have uninstalled and reinstalled the app without success. I'm stumped. The other thing they're reporting is that the icon doesn't even show properly, but rather is a gear in a box, which makes me think that something goes awry very early in the installation process.

    Read the article

  • Converting a Matrix to a grid of colors

    - by Zach
    I'm currently making a console application in C# (will be going to a Windows Form application in the future. Sooner if needed). My current objective is to have a matrix (current size 52x42) be exported as an image (bitmap, jpeg, png, I'm flexible) where each value in the matrix (0, 1, 2, 3) is portrayed as a white, black, blue, or red square of size 20px x 20px with a grid 1px wide seperating each 'cell'. Can this even be done in a console application, and if so how? If not, what would I need to get it working in a Windows Form application?

    Read the article

  • does Apple allow template style apps to pass review?

    - by user1159677
    I have an app which will go to our clients and then they can have their clients install it. Meaning there would be multiple versions of the master app but with customization per client. example 200 of our clients get the master app and then can customize it (text and images only via web) Will Apple allow something like this? Is there another way to get around this distribution model? I guess a good example of it would be a real estate agent having an app that's customized and on the app store but it's still Brand XYZ's app. thanks in advance

    Read the article

  • How to know when a user console is locked or has logged "back into" windows

    - by Paul Kohler
    This is in regards to applications that run in the taskbar but should be applicable to standard apps, Winforms, WPF, etc. Question: I am after some method (preferably via managed code) to be notified when a user either has their screen "locked" while my app is running and/or know when they log back in. GMail Notifier does this sort of thing for example, if my PC is locked for a while when I log in again it shows a list of emails that arrived since locking the PC. I'm looking to replicate that kind of functionality. Does anyone have any ideas on how to accomplish this?

    Read the article

  • Windows 8 Set User Account Image

    - by Nexion
    I'm trying to write a small CONSOLE (not metro style) app to quickly change the user account image of the current user to a select image for a setup scrip that I'm running on a bunch of laptops. They're all Windows 8 and (since it hasn't been out terribly long) I can't find a ton of info on it. I did manage to figure out that you need to use the Windows.System.UserProfile object to do so, but I can't find any documentation on how to do so in a console app. Thoughts? Suggestions?

    Read the article

  • iPhone: Localizing app icon still not supported?

    - by js_
    My app's icon includes some text. So I want to change language of the text by language or country. There is a post which says localizing app icon is not supported: http://useyourloaf.com/blog/2010/12/16/localizing-iphone-app-icon-is-not-supported.html But it was posted in December 2010, one and half years ago from now. Is it still not possible to change icon of app by language? Localizing both icon of app on device and icon on App Store are not supported? Or localizing icon only on App Store is possible?

    Read the article

  • Build Mobile App for E-Business Suite Using SOA Suite and ADF Mobile

    - by Michelle Kimihira
    With the upcoming release of Oracle ADF Mobile, I caught up with Srikant Subramaniam, Senior Principal Product Manager, Oracle Fusion Middleware post OpenWorld to learn about the cool hands-on lab at OpenWorld.  For those of you who missed it, you will want to keep reading... Author: Srikant Subramaniam, Senior Principal Product Manager,Oracle Fusion Middleware Oracle ADF Mobile enables rapid and declarative development of native on-device mobile applications. These native applications provide a richer experience for smart devices users running Apple iOS or other mobile platforms. Oracle ADF Mobile protects Oracle customers from technology shifts by adopting a metadata-based development framework that enables developer to develop one app (using Oracle JDeveloper), and deploy to multiple device platforms (starting with iOS and Android).  Oracle ADF Mobile also enables IT organizations to leverage existing expertise in web-based and Java development by adopting a hybrid application architecture that brings together HTML5, Java, and device native container: HTML5 allows developer to deliver device-native user experiences while maintaining portability across different platforms Java allows developers to create modules to support business logic and data services Native container provides integration into device services such as camera, contacts, etc All these technologies are packaged into a development framework that supports declarative application development through Oracle JDeveloper. ADF Mobile also provides out of box integratoin with key Fusion Middleware components, such as SOA Suite and Business Process Management (BPM). Oracle Fusion Middleware provides the necessary infrastructure to extend business processes and services to the mobile device -- enabling the mobile user to participate in human tasks – without the additional “mobile middleware” layer. When coupled with Oracle SOA Suite, this combination can execute business transactions on Oracle E-Business Suite (or any Oracle Application). Demo Use Case: Mobile E-Business Suite (iExpense) Approvals Using an employee expense approval scenario, we illustrate how to use Oracle Fusion Middleware and Oracle ADF Mobile to build application extensions that integrate intelligently with Oracle Applications (For example, E-Business Suite). Building these extensions using Oracle Fusion middleware and ADF makes modifications simple, quick to implement, and easy to maintain/upgrade. As described earlier, this approach also extends Fusion Middleware to mobile users without the additional "Mobile Middleware" layer. The approver is presented with a list of expense reports that have been submitted for approval. These expense reports are retrieved from the backend E-Business Suite and displayed on the mobile device. Approval (or rejection) of the expense report kicks off the workflow in E-Business Suite and takes it to completion. The demo also shows how to integrate with native device services such as email, contacts, BI dashboards as well as a prebuilt PDF viewer (this is especially useful in the expense approval scenario, as there is often a need for the approver to access the submitted receipts). Summary Oracle recommends Fusion Middleware as the application integration platform to deliver critical enterprise data and processes to mobile applications.  Pre-built connectors between Fusion Middleware and Applications greatly accelerates the integration process.  Instead of building individual integration points between mobile applications and individual enterprise applications, Oracle Fusion Middleware enables IT organizations to leverage a common platform to support both desktop and mobile application.  Additional Information Product Information on Oracle.com: Oracle Fusion Middleware Follow us on Twitter and Facebook Subscribe to our regular Fusion Middleware Newsletter

    Read the article

  • problems programmatically creating UIView on iPad App

    - by user3871
    I have been struggling with this problem for a few days. My iPad app is designed to be a portrait game. To satisfy Apple's expection, I also support landscape mode. When it goes into landscape mode, the game goes into a letterbox format with back borders on the sides. My problem is I am creating the UIWindow and UIView programmatically. For some unkown reason, the touch controls are "locked" in to think I'm always in landscape mode. And even though visually in portrait mode everything looks correct, the top and bottom of the screen does not respond to touch. To summarize how I am setting this up, let me provide the skeletal framework of what I'm doing: in main.cpp: int retVal = UIApplicationMain(argc, argv, nil, @"derbyPoker_ipadAppDelegate"); In the delegate, I am doing this: - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { CGRect screenBounds = [[UIScreen mainScreen] bounds]; CGFloat scale = [[ UIScreen mainScreen] scale ]; m_device_width = screenBounds.size.width; m_device_height = screenBounds.size.height; m_device_scale = scale; // Everything is built assuming 640x960 window = [[ UIWindow alloc ] initWithFrame:[[UIScreen mainScreen] bounds]]; viewController = [ glView new ]; [self doStateChange:[blitz class]]; return YES; } The last bit of code sets up the UIView... - (void) doStateChange: (Class) state{ viewController.view = [[state alloc] initWithFrame:CGRectMake(0, 0, m_device_width, m_device_height) andManager:self]; viewController.view.contentMode = UIViewContentModeScaleAspectFit; viewController.view.autoresizesSubviews = YES; [window addSubview:viewController.view]; [window makeKeyAndVisible]; } The problem seems to related to the line viewController.view.contentMode = UIViewContentModeScaleAspectFit; If I remove that line, touch works correctly in portrait mode. But the negative is when I'm landscape mode, the game stretches incorrectly. So That's not a option. The frustrating thing is, when I originally had this set up with a NIB file, it worked fine. I have read through the docs about UIWindow, UIViewController and UIView and have tried about everything to no avail. Any help would be greatly appreciated.

    Read the article

  • Binding MediaElement to a ViewModel in a Windows 8 Store App

    - by jdanforth
    If you want to play a video from your video-library in a MediaElement control of a Metro Windows Store App and tried to bind the Url of the video file as a source to the MediaElement control like this, you may have noticed it’s not working as well for you: <MediaElement Source="{Binding Url}" /> I have no idea why it’s not working, but I managed to get it going using  ContentControl instead: <ContentControl Content="{Binding Video}" /> The code behind for this is: protected override void OnNavigatedTo(NavigationEventArgs e) {     _viewModel = new VideoViewModel("video.mp4");     DataContext = _viewModel; } And the VideoViewModel looks like this: public class VideoViewModel {     private readonly MediaElement _video;     private readonly string _filename;       public VideoViewModel(string filename)     {         _filename = filename;         _video = new MediaElement { AutoPlay = true };         //don't load the stream until the control is ready         _video.Loaded += VideoLoaded;     }       public MediaElement Video     {         get { return _video; }     }       private async void VideoLoaded(object sender, RoutedEventArgs e)     {         var file = await KnownFolders.VideosLibrary.GetFileAsync(_filename);         var stream = await file.OpenAsync(FileAccessMode.Read);         _video.SetSource(stream, file.FileType);     } } I had to wait for the MediaElement.Loaded event until I could load and set the video stream.

    Read the article

  • Android launches system settings instead of my app

    - by jsundin
    Hi, For some reason whenever I (try to) start my app the phone decides to launch system settings instead of my "main activity". And yes, I am referring to the "Android system settings", and not something from my app. This only happens on my phone, and I suppose it probably could be related to the fact that my app had just opened system settings when I decided to re-launch with a new version from Eclipse. It is possible to start the app from within Eclipse, but when I navigate back from the app it returns to the system settings rather than the home screen, as if the settings activity was started first and then my activity. If I then start the app from the phone all I get is system settings yet again. The app is listening to the VIEW-action for a specific URL substring, and when I start the app using a matching URL I get the same result as when I start it from Eclipse, app starts, but when I return I return to settings. I have tried googling for this problem, and all I could find was something about Android saving state when an app gets killed, but without any information on how to reset this state. I have tried uninstalling the app, killing system settings, rebooting the phone, reinstalling, clearing application data.. no luck.. For what it's worth, here's the definition of my main activity from the manifest, <activity android:name=".HomeActivity" android:label="@string/app_name" android:screenOrientation="portrait" android:clearTaskOnLaunch="true" android:launchMode="singleTop"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> <intent-filter> <action android:name="android.intent.action.VIEW"></action> <category android:name="android.intent.category.DEFAULT"></category> <category android:name="android.intent.category.BROWSABLE"></category> <data android:pathPrefix="/isak-web-mobile/smart/" android:scheme="http" android:host="*"></data> </intent-filter> </activity> And here is the logcat-line from when I try to start my app, nothing about any settings anywhere. I/ActivityManager( 1301): Starting activity: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10200000 cmp=se.opencare.isak/.HomeActivity } When I launch from Eclipse I also get this line (as one would expect), I/ActivityManager( 1301): Start proc se.opencare.isak for activity se.opencare.isak/.HomeActivity: pid=23068 uid=10163 gids={3003, 1007, 1015} If it matters the phone is a HTC Desire Z running 2.2.1. Currently, this is my HomeActivity, public class HomeActivity extends Activity { public static final String TAG = "HomeActivity"; @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { Log.d(TAG, "onActivityResult(" + requestCode + ", " + resultCode + ", " + data + ")"); super.onActivityResult(requestCode, resultCode, data); } @Override protected void onCreate(Bundle savedInstanceState) { Log.d(TAG, "onCreate(" + savedInstanceState + ")"); super.onCreate(savedInstanceState); } @Override protected void onDestroy() { Log.d(TAG, "onDestroy()"); super.onDestroy(); } @Override protected void onPause() { Log.d(TAG, "onPause()"); super.onPause(); } @Override protected void onPostCreate(Bundle savedInstanceState) { Log.d(TAG, "onPostCreate(" + savedInstanceState + ")"); super.onPostCreate(savedInstanceState); } @Override protected void onPostResume() { Log.d(TAG, "onPostResume()"); super.onPostResume(); } @Override protected void onRestart() { Log.d(TAG, "onRestart()"); super.onRestart(); } @Override protected void onRestoreInstanceState(Bundle savedInstanceState) { Log.d(TAG, "onRestoreInstanceState(" + savedInstanceState + ")"); super.onRestoreInstanceState(savedInstanceState); } @Override protected void onResume() { Log.d(TAG, "onResume()"); super.onResume(); } @Override protected void onStart() { Log.d(TAG, "onStart()"); super.onStart(); } @Override protected void onStop() { Log.d(TAG, "onStop()"); super.onStop(); } @Override protected void onUserLeaveHint() { Log.d(TAG, "onUserLeaveHint()"); super.onUserLeaveHint(); } } Nothing (of the above) is written to the log.

    Read the article

  • Xbox : la prochaine console sera baptisée Loop, plus petite et moins chère, elle sera sous Windows 9 avec un processeur ARM

    Xbox : la prochaine console sera baptisée Loop, Plus petite et moins chère, elle sera sous Windows 9 avec un processeur ARMe Ça devient presque une coutume pour certains produits de Microsoft dont la firme se garde de divulguer toute information officielle. Comme c'était le cas pour Windows 8, les rumeurs sur la prochaine console Xbox font à leur tour le « buz » sur la toile. Selon un article du site MSNerd, le successeur de la Xbox 360 pourrait être baptisé Xbox 720, et aura pour nom de code « Loop ». Plus petite et moins couteuse, cette console fonctionnera sous une version adaptée de Windows 9, avec un ...

    Read the article

  • Implementing an async "read all currently available data from stream" operation

    - by Jon
    I recently provided an answer to this question: C# - Realtime console output redirection. As often happens, explaining stuff (here "stuff" was how I tackled a similar problem) leads you to greater understanding and/or, as is the case here, "oops" moments. I realized that my solution, as implemented, has a bug. The bug has little practical importance, but it has an extremely large importance to me as a developer: I can't rest easy knowing that my code has the potential to blow up. Squashing the bug is the purpose of this question. I apologize for the long intro, so let's get dirty. I wanted to build a class that allows me to receive input from a console's standard output Stream. Console output streams are of type FileStream; the implementation can cast to that, if needed. There is also an associated StreamReader already present to leverage. There is only one thing I need to implement in this class to achieve my desired functionality: an async "read all the data available this moment" operation. Reading to the end of the stream is not viable because the stream will not end unless the process closes the console output handle, and it will not do that because it is interactive and expecting input before continuing. I will be using that hypothetical async operation to implement event-based notification, which will be more convenient for my callers. The public interface of the class is this: public class ConsoleAutomator { public event EventHandler<ConsoleOutputReadEventArgs> StandardOutputRead; public void StartSendingEvents(); public void StopSendingEvents(); } StartSendingEvents and StopSendingEvents do what they advertise; for the purposes of this discussion, we can assume that events are always being sent without loss of generality. The class uses these two fields internally: protected readonly StringBuilder inputAccumulator = new StringBuilder(); protected readonly byte[] buffer = new byte[256]; The functionality of the class is implemented in the methods below. To get the ball rolling: public void StartSendingEvents(); { this.stopAutomation = false; this.BeginReadAsync(); } To read data out of the Stream without blocking, and also without requiring a carriage return char, BeginRead is called: protected void BeginReadAsync() { if (!this.stopAutomation) { this.StandardOutput.BaseStream.BeginRead( this.buffer, 0, this.buffer.Length, this.ReadHappened, null); } } The challenging part: BeginRead requires using a buffer. This means that when reading from the stream, it is possible that the bytes available to read ("incoming chunk") are larger than the buffer. Remember that the goal here is to read all of the chunk and call event subscribers exactly once for each chunk. To this end, if the buffer is full after EndRead, we don't send its contents to subscribers immediately but instead append them to a StringBuilder. The contents of the StringBuilder are only sent back whenever there is no more to read from the stream. private void ReadHappened(IAsyncResult asyncResult) { var bytesRead = this.StandardOutput.BaseStream.EndRead(asyncResult); if (bytesRead == 0) { this.OnAutomationStopped(); return; } var input = this.StandardOutput.CurrentEncoding.GetString( this.buffer, 0, bytesRead); this.inputAccumulator.Append(input); if (bytesRead < this.buffer.Length) { this.OnInputRead(); // only send back if we 're sure we got it all } this.BeginReadAsync(); // continue "looping" with BeginRead } After any read which is not enough to fill the buffer (in which case we know that there was no more data to be read during the last read operation), all accumulated data is sent to the subscribers: private void OnInputRead() { var handler = this.StandardOutputRead; if (handler == null) { return; } handler(this, new ConsoleOutputReadEventArgs(this.inputAccumulator.ToString())); this.inputAccumulator.Clear(); } (I know that as long as there are no subscribers the data gets accumulated forever. This is a deliberate decision). The good This scheme works almost perfectly: Async functionality without spawning any threads Very convenient to the calling code (just subscribe to an event) Never more than one event for each time data is available to be read Is almost agnostic to the buffer size The bad That last almost is a very big one. Consider what happens when there is an incoming chunk with length exactly equal to the size of the buffer. The chunk will be read and buffered, but the event will not be triggered. This will be followed up by a BeginRead that expects to find more data belonging to the current chunk in order to send it back all in one piece, but... there will be no more data in the stream. In fact, as long as data is put into the stream in chunks with length exactly equal to the buffer size, the data will be buffered and the event will never be triggered. This scenario may be highly unlikely to occur in practice, especially since we can pick any number for the buffer size, but the problem is there. Solution? Unfortunately, after checking the available methods on FileStream and StreamReader, I can't find anything which lets me peek into the stream while also allowing async methods to be used on it. One "solution" would be to have a thread wait on a ManualResetEvent after the "buffer filled" condition is detected. If the event is not signaled (by the async callback) in a small amount of time, then more data from the stream will not be forthcoming and the data accumulated so far should be sent to subscribers. However, this introduces the need for another thread, requires thread synchronization, and is plain inelegant. Specifying a timeout for BeginRead would also suffice (call back into my code every now and then so I can check if there's data to be sent back; most of the time there will not be anything to do, so I expect the performance hit to be negligible). But it looks like timeouts are not supported in FileStream. Since I imagine that async calls with timeouts are an option in bare Win32, another approach might be to PInvoke the hell out of the problem. But this is also undesirable as it will introduce complexity and simply be a pain to code. Is there an elegant way to get around the problem? Thanks for being patient enough to read all of this. Update: I definitely did not communicate the scenario well in my initial writeup. I have since revised the writeup quite a bit, but to be extra sure: The question is about how to implement an async "read all the data available this moment" operation. My apologies to the people who took the time to read and answer without me making my intent clear enough.

    Read the article

  • Log4Net in App object?

    - by David Veeneman
    I am getting started with Logging in a WPF desktop app, using Log4Net as the logging component. Here is my question: In a simple desktop app, is there any reason not to instantiate my logger as a property ov the App class (App.xaml.cs), like this? public partial class App : Application { private static readonly ILog p_Logger = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType); public ILog Logger { get { return p_Logger; } } #endregion } } That would allow me to invoke the logger

    Read the article

< Previous Page | 81 82 83 84 85 86 87 88 89 90 91 92  | Next Page >