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  • How can the AssemblyName class be used for existing Assemblies?

    - by IbrarMumtaz
    This is another exam related question. I want to know how can I use the AssemblyName class to represent an existing assembly that already exists on disk??? I am talking about from the perspective of using the AppDomain's instance method .Load(), that takes an AssemblyName object as a parameter. I know what MSDN has to say about what the .Load() method was designed for but that aside, I still want to know how to use it !!!

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  • Achieving C# "readonly" behavior in C++

    - by Tommy Fisk
    Hi guys, this is my first question on stack overflow, so be gentle. Let me first explain the exact behavior I would like to see. If you are familiar with C# then you know that declaring a variable as "readonly" allows a programmer to assign some value to that variable exactly once. Further attempts to modify the variable will result in an error. What I am after: I want to make sure that any and all single-ton classes I define can be predictably instantiated exactly once in my program (more details at the bottom). My approach to realizing my goal is to use extern to declare a global reference to the single-ton (which I will later instantiate at a time I choose. What I have sort of looks like this, namespace Global { extern Singleton& mainInstance; // not defined yet, but it will be later! } int main() { // now that the program has started, go ahead and create the singleton object Singleton& Global::mainInstance = Singleton::GetInstance(); // invalid use of qualified name Global::mainInstance = Singleton::GetInstance(); // doesn't work either :( } class Singleton { /* Some details ommited */ public: Singleton& GetInstance() { static Singleton instance; // exists once for the whole program return instance; } } However this does not really work, and I don't know where to go from here. Some details about what I'm up against: I'm concerned about threading as I am working on code that will deal with game logic while communicating with several third-party processes and other processes I will create. Eventually I would have to implement some kind of synchronization so multiple threads could access the information in the Singleton class without worry. Because I don't know what kinds of optimizations I might like to do, or exactly what threading entails (never done a real project using it), I was thinking that being able to predictably control when Singletons were instantiated would be a Good Thing. Imagine if Process A creates Process B, where B contains several Singletons distributed against multiple files and/or libraries. It could be a real nightmare if I can not reliably ensure the order these singleton objects are instantiated (because they could depend on each other, and calling methods on a NULL object is generally a Bad Thing). If I were in C# I would just use the readonly keyword, but is there any way I can implement this (compiler supported) behavior in C++? Is this even a good idea? Thanks for any feedback.

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  • Not sure what happens to my apps objects when using NSURLSession in background - what state is my app in?

    - by Avner Barr
    More of a general question - I don't understand the workings of NSURLSession when using it in "background session mode". I will supply some simple contrived example code. I have a database which holds objects - such that portions of this data can be uploaded to a remote server. It is important to know which data/objects were uploaded in order to accurately display information to the user. It is also important to be able to upload to the server in a background task because the app can be killed at any point. for instance a simple profile picture object: @interface ProfilePicture : NSObject @property int userId; @property UIImage *profilePicture; @property BOOL successfullyUploaded; // we want to know if the image was uploaded to out server - this could also be a property that is queryable but lets assume this is attached to this object @end Now Lets say I want to upload the profile picture to a remote server - I could do something like: @implementation ProfilePictureUploader -(void)uploadProfilePicture:(ProfilePicture *)profilePicture completion:(void(^)(BOOL successInUploading))completion { NSUrlSession *uploadImageSession = ..... // code to setup uploading the image - and calling the completion handler; [uploadImageSession resume]; } @end Now somewhere else in my code I want to upload the profile picture - and if it was successful update the UI and the database that this action happened: ProfilePicture *aNewProfilePicture = ...; aNewProfilePicture.profilePicture = aImage; aNewProfilePicture.userId = 123; aNewProfilePicture.successfullyUploaded = NO; // write the change to disk [MyDatabase write:aNewProfilePicture]; // upload the image to the server ProfilePictureUploader *uploader = [ProfilePictureUploader ....]; [uploader uploadProfilePicture:aNewProfilePicture completion:^(BOOL successInUploading) { if (successInUploading) { // persist the change to my db. aNewProfilePicture.successfullyUploaded = YES; [Mydase update:aNewProfilePicture]; // persist the change } }]; Now obviously if my app is running then this "ProfilePicture" object is successfully uploaded and all is well - the database object has its own internal workings with data structures/caches and what not. All callbacks that may exist are maintained and the app state is straightforward. But I'm not clear what happens if the app "dies" at some point during the upload. It seems that any callbacks/notifications are dead. According to the API documentation- the uploading is handled by a separate process. Therefor the upload will continue and my app will be awakened at some point in the future to handle completion. But the object "aNewProfilePicture" is non existant at that point and all callbacks/objects are gone. I don't understand what context exists at this point. How am I supposed to ensure consistency in my DB and UI (For instance update the "successfullyUploaded" property for that user)? Do I need to re-work everything touching the DB or UI to correspond with the new API and work in a context free environment?

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  • What causes POCO proxy entities to only sometimes be created in Entity Framework 4.

    - by Kohan
    I have set up my POCOs and I have marked their public properties as virtual and I am successfully getting Proxies most of the time (95%) but randomly I am getting EF return some proxies and some non-proxies. Recycling the app pool when this happens will then fix this instance of the error and it will go away for an amount of time. Then it will re-occur in some other random (it seems) place. What can cause this sort of behaviour? Thanks, Kohan

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  • Linq DBML multiple sql servers

    - by Hurricanepkt
    I have an archive system that had to be on two sql databases for simplicity one is Archive2009 and the other Archive2010 they are both on the same sql server and instance and have identical structures however I have a page that needs to view the old one and the new one (I can make two seperate pages) How best would I go about doing this? Dynamically changing the connection string etc?

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  • initialize a const array in a class initializer in C++

    - by Nathan Fellman
    I have the following class in C++: class a { const int b[2]; // other stuff follows // and here's the constructor a(void); } The question is, how do I initialize b in the initialization list, given that I can't initialize it inside the body of the function of the constructor, because b is const? This doesn't work: a::a(void) : b([2,3]) { // other initialization stuff } Edit: The case in point is when I can have different values for b for different instances, but the values are known to be constant for the lifetime of the instance.

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  • How does Python store lists internally?

    - by Mike Cooper
    How are lists in python stored internally? Is it an array? A linked list? Something else? Or does the interpreter guess at the right structure for each instance based on length, etc. If the question is implementation dependent, what about the classic CPython?

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  • Core data fetch only returns unique managed objects

    - by JK
    I execute a core data fetch which specifies a predicate as follows: NSPredicate *predicate = [NSPredicate predicateWithFormat:@"identifier IN %@", favoritesIDs]; When there are duplicate items in the favoriteIDs array, the fetch request only returns 1 managed object. How can I ensure that more than one instance is fetched? Thank you.

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  • How to check if a BOOL is null?

    - by Sheehan Alam
    Is there a way I can check to see if a value is NULL/Nil before assigning it to a BOOL? For example, I have a value in a NSDictionary that can be either TRUE/FALSE/NULL mySTUser.current_user_following = [[results objectForKey:@"current_user_following"]boolValue]; When the value is NULL I get the following error *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSNull boolValue]: unrecognized selector sent to instance I would like to be able to handle the NULL case.

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  • What is the meaning of this C++ Error std::length_error

    - by Janusz
    While running my program I get this Error: terminate called after throwing an instance of 'std::length_error' what(): basic_string::_S_create Abort trap I know that you can't do much without the code but I think that error is to deep in the code to copy all of it. Maybe I can figure it out if I understand what this error means. Is this a sign for an issue with reading or writing at the wrong memory address? Is there something I can do to get more information about the problem from my program?

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  • Setting column width in Table View

    - by Jeremy
    I am having a hard time understanding how to change the width of columns when creating a table view. I know you can set the width in pixels of a column but that is not what I want to do. Say, for instance, I have 2 columns and want each column to take up half the screen. How do I do this without explicitly setting the pixels, so that my code can work on multiple screen sizes?

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  • Grails: How can I search through children in a hasMany relationship?

    - by intargc
    If I have a Client domain class, and that Client hasMany Courses. How do I find the course I'm looking for? For instance: class Client { String name static hasMany = [courses:Course] } class Course { String name static belongsTo = [client:Client] } def client = Client.get(1) I want to "find" or "search" within that courses relationship. Maybe something like: client.courses.find(name:'Whatever') Is there any way to do this with Grails?

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  • Doubleton Pattern Implementation

    - by Pierreten
    I'm leveraging the Doubleton Pattern from this link http://www.codeproject.com/KB/architecture/designpattern_doubleton.aspx in my own code. I think it makes things a lot easier since the Singleton only provides one instance, but I get two with this pattern. I was wondering if it would make sense to have it implement an interface so I can inject it into my domain layer.

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  • Should I sanitize EVERY form variable passed along?

    - by Camran
    I have a form with many fields... The action is set to a php page which queries mysql... Should I sanitize with mysql_real_escape_string every single variable? Or can I ignore sanitizing drop-lists and radios for instance? Also, besides mysql_real_escape_string, what else should I do to prevent attacks? Thanks

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  • drupal taxonomy

    - by slimcady
    I have several different content type nodes (videos, image galleries, stories...) that I would like to categorize and create a top-level page that aggregates these nodes. So for example, the top-level page would have teaser thumbnails very similar to the front page view but of course filtered for that topic (like for instance automobiles, and motorcycles would have its own page, etc...). What is the best way to accomplish this? Taxonomy? Views?

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  • Custom Page tagging in Google Analytics

    - by Jason
    I want to have custom page tags, which are different from URLs I have, in my Google Analytics report page. For instance, Actual URL - /news/today_news.php page tag on Google Analytics - /news/today_news.php/Category.News/TodayNews How can I make the custom page tag with Google Analytics API?

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  • How to listen to that property?

    - by mystify
    @constant kAudioSessionProperty_AudioInputAvailable A UInt32 with a value other than zero when audio input is available. Use this property, rather than the device model, to determine if audio input is available. A listener will notify you when audio input becomes available. For instance, when a headset is attached to the second generation iPod Touch, audio input becomes available via the wired microphone. So, if I wanted to get notified about kAudioSessionProperty_AudioInputAvailable, how would I do that?

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