Search Results

Search found 40386 results on 1616 pages for 'object design'.

Page 316/1616 | < Previous Page | 312 313 314 315 316 317 318 319 320 321 322 323  | Next Page >

  • How would I associate a "Note" class to 4+ classes without creating lookup table for each associatio

    - by Gthompson83
    Im creating a project tasklist application. I have project, section, task, issue classes, and would like to use one class to be able to add simple notes to any object instance of those classes. The task, issue tables both use a standard identity field as a primary key. The section table has a two field primary key. The project table has a single int primary key defined by the user. Is there a way to associate the note class with each of these without using a seperate lookup table for each class? I'm not so sure my original idea is a decent way to implement this. I considered the following (each variable mapping to a field n the notes table. Private _NoteId As Integer Private _ProjectId As Integer Private _SectionId As Integer Private _SectionId2 As Integer Private _TaskId As Integer Private _IssueId As Integer Private _Note As String Private _UserId As Guid Then I would be able to write seperate methods (getProjectNotes, getTaskNotes) to get notes attached to each class. I started writing this a few weeks ago but got pulled away before i could finish. When revisiting this code today my first thought "this is retarded". Thoughts on drawbacks to this design?

    Read the article

  • Why aren't variables declared in "try" in scope in "catch" or "finally"?

    - by Jon Schneider
    In C# and in Java (and possibly other languages as well), variables declared in a "try" block are not in scope in the corresponding "catch" or "finally" blocks. For example, the following code does not compile: try { String s = "test"; // (more code...) } catch { Console.Out.WriteLine(s); //Java fans: think "System.out.println" here instead } In this code, a compile-time error occurs on the reference to s in the catch block, because s is only in scope in the try block. (In Java, the compile error is "s cannot be resolved"; in C#, it's "The name 's' does not exist in the current context".) The general solution to this issue seems to be to instead declare variables just before the try block, instead of within the try block: String s; try { s = "test"; // (more code...) } catch { Console.Out.WriteLine(s); //Java fans: think "System.out.println" here instead } However, at least to me, (1) this feels like a clunky solution, and (2) it results in the variables having a larger scope than the programmer intended (the entire remainder of the method, instead of only in the context of the try-catch-finally). My question is, what were/are the rationale(s) behind this language design decision (in Java, in C#, and/or in any other applicable languages)?

    Read the article

  • Why is Excel's 'Evaluate' method a general expression evaluator?

    - by jtolle
    A few questions have come up recently involving the Application.Evaluate method callable from Excel VBA. The old XLM macro language also exposes an EVALUATE() function. Both can be quite useful. Does anyone know why the evaluator that is exposed can handle general expressions, though? My own hunch is that Excel needed to give people a way to get ranges from string addresses, and to get the value of named formulas, and just opening a portal to the expression evaluator was the easiest way. (The help for the VBA version does say its purpose it to "convert a Microsoft Excel name to an object or a value".) But of course you don't need the ability to evaluate arbitrary expressions just to do that. (That is, Excel could provide a Name.Evaluate method or something instead.) Application.Evaluate seems kind of...unfinished. It's full behavior isn't very well documented, and there are quite a few quirks and limitations (as described by Charles Williams here: http://www.decisionmodels.com/calcsecretsh.htm) with what is exposed. I suppose the answer could be simply "why not expose it?", but I'd be interested to know what design decisions led to this feature taking the form that it does. Failing that, I'd be interested to hear other hunches.

    Read the article

  • How to understand other people's CSS architectures?

    - by John
    I am reasonably good with CSS. However, when working with someone else's CSS, it's difficult for me to see the "bigger picture" in their architecture (but i have no problem when working with a CSS sheet I wrote myself). For example, I have no problems using Firebug to isolate and fix cross browser compatibility issues, or fixing a floating issue, or changing the height on a particular element. But if I'm asked to do something drastic such as, "I want the right sidebars of pages A, B, C and D to have a red border. I want the right side bars of pages E, F and G to have a blue border if and only if the user mouses over", then it takes me time a long time to map out all the CSS inheritance rules to see the "bigger picture". For some reason, I don't encounter the same difficulty with backend code. After a quick debriefing of how a feature works, and a quick inspection of the controller and model code, I will feel comfortable with the architecture. I will think, "it's reasonable to assume that there will be an Employee class that inherits from the Person Class that's used by a Department controller". If I discover inconvenient details that aren't consistent with overall architectural style, I am confident that I can hammer things back in place. With someone else's CSS work, it's much harder for me to see the "relationships" between different classes, and when and how the classes are used. When there are many inheritance rules, I feel overwhelmed. I'm having trouble articulating my question and issues... All I want to know is, why is it so much harder for me to see the bigger picture in someone else's CSS architecture than compared to someone else's business logic layer? **Does it have any thing to do with CSS being a relatively new technology, and there aren't many popular design patterns?

    Read the article

  • Scalably processing large amount of comlpicated database data in PHP, many times a day.

    - by Eph
    I'm soon to be working on a project that poses a problem for me. It's going to require, at regular intervals throughout the day, processing tens of thousands of records, potentially over a million. Processing is going to involve several (potentially complicated) formulas and the generation of several random factors, writing some new data to a separate table, and updating the original records with some results. This needs to occur for all records, ideally, every three hours. Each new user to the site will be adding between 50 and 500 records that need to be processed in such a fashion, so the number will not be steady. The code hasn't been written, yet, as I'm still in the design process, mostly because of this issue. I know I'm going to need to use cron jobs, but I'm concerned that processing records of this size may cause the site to freeze up, perform slowly, or just piss off my hosting company every three hours. I'd like to know if anyone has any experience or tips on similar subjects? I've never worked at this magnitude before, and for all I know, this will be trivial to the server and not pose much of an issue. As long as ALL records are processed before the next three hour period occurs, I don't care if they aren't processed simultaneously (though, ideally, all records belonging to a specific user should be processed in the same batch), so I've been wondering if I should process in batches every 5 minutes, 15 minutes, hour, whatever works, and how best to approach this (and make it scalable in a way that is fair to all users)?

    Read the article

  • Rate my C# code (~300 SLOC) using GDI+/Backgroundworker

    - by sebastianlarsson
    Hi, I want to get some feedback on my code! Below is some background info. I am taking a pre-certification course in C# (Sweden, 15 ECTS). The focus of the course is theoretical and only limited practical work. I dont find the assignments very hard at all to tell you the truth, but since I only have very limited work experience as a developer (I have worked 15h/week at Ericsson since November) I think I would benefit from having the certificate (70-536 and more probably). I am currently reading Martin Fowler's "Refactoring: Improving the design of existing code" and I tried to apply his techniques to my latest lab in the course. I have been on the lookout for a website which have the idea of providing feedback on code, but so far I have yet to discover any. Please take a look on my code and tell me what you think. It is only roughly 300 lines of code divided into a couple of classes. GDI+, backgroundworker and user controls are what the lab is about. I reckon you may have to spend as little as a couple of minutes on looking on the solution. Link to solution: http://www.filefactory.com/file/b18h7d5/n/Lab4_Lab5_SebastianLarsson.zip Regards and thank you, Sebastian

    Read the article

  • .NET: bool vs enum as a method parameter

    - by Julien Lebosquain
    Each time I'm writing a method that takes a boolean parameter representing an option, I find myself thinking: "should I replace this by an enum which would make reading the method calls much easier?". Consider the following with an object that takes a parameter telling whether the implementation should use its thread-safe version or not (I'm not asking here if this way of doing this is good design or not, only the use of the boolean): public void CreateSomeObject(bool makeThreadSafe); CreateSomeObject(true); When the call is next to the declaration the purpose of the parameter seems of course obvious. When it's in some third party library you barely know, it's harder to immediately see what the code does, compared to: public enum CreationOptions { None, MakeThreadSafe } public void CreateSomeObject(CreationOptions options); CreateSomeObject(CreationOptions.MakeThreadSafe); which describes the intent far better. Things get worse when there's two boolean parameters representing options. See what happened to ObjectContext.SaveChanges(bool) between Framework 3.5 and 4.0. It has been obsoleted because a second option has been introduced and the whole thing has been converted to an enum. While it seems obvious to use an enumeration when there's three elements or more, what's your opinion and experiences about using an enum instead a boolean in these specific cases?

    Read the article

  • Where to start with map application

    - by rfders
    Hi there, i'm trying to desing a new application which allow user see he/her current location on a custom map (office, university compus, etc). but actually i have a couple of question in my mind (i haven't designed this kind of application before). i'm wondering: How can i draw my own maps, what is the best option for it? there any format that i have to care of, there are any specification about it ? Once i have my custom map. how can i do to mapping a global position system with the local positions ? What are the tricks behing zoom on maps ? just differents layers with more or less informations and those layers changes on users demand ? If a whant to mark some specific points over the map, like a cafeteria, boss's office etc, how can i do that ? Sorry if my questions are too much generics and dumb, but i really need some clues about this topic because i don't have any idea how to design this kind of application as best as possible. and we don't whant to reinvent the wheel. I will appreciate any help that you can provide me in order to desing this application

    Read the article

  • How security of the systems might be improved using database procedures?

    - by Centurion
    The usage of Oracle PL/SQL procedures for controlling access to data often emphasized in PL/SQL books and other sources as being more secure approach. I'v seen several systems where all business logic related with data is performed through packages, procedures and functions, so application code becomes quite "dumb" and is only responsible for visualization part. I even heard some devs call such approaches and driving architects as database nazi :) because all logic code resides in database. I do know about DB procedure performance benefits, but now I'm interested in a "better security" when using thick client model. I assume such design mostly used when Oracle (and maybe MS SQL Server) databases are used. I do agree such approach improves security but only if there are not much users and every system user has a database account, so we might control and monitor data access through standard database user security. However, how such approach could increase the security for an average web system where thick clients are used: for example one database user with DML grants on all tables, and other users are handled using "users" and"user_rights" tables? We could use DB procedures, save usernames into context use that for filtering but vulnerability resides at the root - if the main database account is compromised than nothing will help. Of course in a real system we might consider at least several main users (for example frontend_db_user, backend_db_user).

    Read the article

  • Is "tip-of-the-day" good?

    - by Jonta
    Many programs (often large ones, like MS Office, The GIMP, Maxthon) have a feature called "tip-of-the-day". It explains a small part of the program, like this one in Maxthon: "You can hide/show the main menu bar by pressing Ctrl+F11" You can usually browse through them by clicking next. And other options provided are "Previous", "Close", "Do not show at startup". I think I like the way Maxthon used to handle this; in the browser's statusbar (down at the bottom usually, together with "Done", the progress-bar etc), there would sometimes be a small hint or tip on what else you could do with it. As Joel Spolsky wrote in his article-series "User Interface Design for Programmers", people don't like reading manuals. But we still want them to use the program, and the features they could benefit from, don't we? Therefore, I think it is useful to have such a feature, without the annoyance of the pop-up on startup. What do you think? Pop-up? Maxthonstyle? No way?

    Read the article

  • Structuring iPhone/iPad application views

    - by Mark
    I have an idea about an application that I want to build and Im new to iPhone/iPad development (but not new to development in other languages/frameworks such as .NET and Java). I want to layout some views on the screen so that they animate (slide in) from different directions into their places. The question is about the strucuture of the application, if I have say 4 rectanglular areas on the screen that contain business data, such as contacts (name, photo, etc...) and they all take up different widths of the screen (say the first contact takes up one row of the screen, but the next 2 take up half the width of the next row each, and so on). Should I create a custom view for the different sized contact views, (i.e. LargeCustomView and SmallCustomView, and any other special type that I make) or should it all be one type, say, CustomerDetailsView which could be stretched to fit at design time? Also, if there were, say, 3 different instances of the same custom view on the one screen, are there 3 instances of the view controller also? Im a little confused about powering the data behind a view, can someone shed some light on this for me? Do I just set the properties (say an instance variable ContactForView) on the view controller for each instance? Thanks for any help you can give Cheers, Mark

    Read the article

  • Multiple Foreign keys to a single table and single key pointing to more than one table

    - by user1216775
    I need some suggestions from the database design experts here. I have around six foreign keys into a single table (defect) which all point to primary key in user table. It is like: defect (.....,assigned_to,created_by,updated_by,closed_by...) If I want to get information about the defect I can make six joins. Do we have any better way to do it? Another one is I have a states table which can store one of the user-defined set of values. I have defect table and task table and I want both of these tables to share the common state table (New, In Progress etc.). So I created: task (.....,state_id,type_id,.....) defect(.....,state_id,type_id,...) state(state_id,state_name,...) importance(imp_id,imp_name,...) There are many such common attributes along with state like importance(normal, urgent etc), priority etc. And for all of them I want to use same table. I am keeping one flag in each of the tables to differentiate task and defect. What is the best solution in such a case? If somebody is using this application in health domain, they would like to assign different types, states, importances for their defect or tasks. Moreover when a user selects any project I want to display all the types,states etc under configuration parameters section.

    Read the article

  • [MVC] logic before dispatcher + controller?

    - by Spoonface
    I believe for a typical MVC web application the router / dispatcher routine is used to decide which controller is loaded based primarily on the area requested in the url by the user. However, in addition to checking the url query string, I also like to use the dispatcher to check whether the user is currently logged in or not to decide which controller is loaded. For example if they are logged in and request the login page, the dispatcher would load their account instead. But is this a fairly non-standard design? Would it violate MVC in any way? I only ask as the examples I've read through this weekend have had no major calculations performed before the dispatcher routine, and commonly check whether the user is logged in or not per controller, and then redirect where necessary. But to me it seems odd to redirect a logged in user from the login area to account area if you could just load the account controller in the first place? I hope I've explained my consternation well enough, but could anyone offer some details on how they handle logged in users, and similar session data?

    Read the article

  • Designing a database for a user/points system? (in Django)

    - by AP257
    First of all, sorry if this isn't an appropriate question for StackOverflow. I've tried to make it as generalisable as possible. I want to create a database (MySQL, site running Django) that has users, who can be allocated a certain number of points for various types of action - it's a collaborative game. My requirements are to obtain: the number of points a user has the user's ranking compared to all other users and the overall leaderboard (i.e. all users ranked in order of points) This is what I have so far, in my Django models.py file: class SiteUser(models.Model): name = models.CharField(max_length=250 ) email = models.EmailField(max_length=250 ) date_added = models.DateTimeField(auto_now_add=True) def points_total(self): points_added = PointsAdded.objects.filter(user=self) points_total = 0 for point in points_added: points_total += point.points return points_total class PointsAdded(models.Model): user = models.ForeignKey('SiteUser') action = models.ForeignKey('Action') date_added = models.DateTimeField(auto_now_add=True) def points(self): points = Action.objects.filter(action=self.action) return points class Action(models.Model): points = models.IntegerField() action = models.CharField(max_length=36) However it's rapidly becoming clear to me that it's actually quite complex (in Django query terms at least) to figure out the user's ranking and return the leaderboard of users. At least, I'm finding it tough. Is there a more elegant way to do something like this? This question seems to suggest that I shouldn't even have a separate points table - what do people think? It feels more robust to have separate tables, but I don't have much experience of database design.

    Read the article

  • Social Networking & Network Affiliations

    - by Code Sherpa
    Hi. I am in the process of planning a database for a social networking project and stumbled upon this url which is a (crude) reverse engineered guess at facebook's schema: http://www.flickr.com/photos/ikhnaton2/533233247/ What is of interest to me is the notion of "Affiliations" and I am trying to fully understand how they work, technically speaking. Where I am somewhat confused is the NetworkID column in the FacebookGroups", "FacebookEvent", and "Affiliations" tables (NID in Affiliations). How are these network affiliations interconnected? In my own project, I have a simple profile table: CREATE TABLE [dbo].[Profiles]( [profileid] [int] IDENTITY(1,1) NOT NULL, [userid] [uniqueidentifier] NOT NULL, [username] [varchar](255) COLLATE Latin1_General_CI_AI NOT NULL, [applicationname] [varchar](255) COLLATE Latin1_General_CI_AI NOT NULL, [isanonymous] [bit] NULL, [lastactivity] [datetime] NULL, [lastupdated] [datetime] NULL, CONSTRAINT [PK__Profiles__1DB06A4F] PRIMARY KEY CLUSTERED ( [profileid] ASC )WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY], CONSTRAINT [PKProfiles] UNIQUE NONCLUSTERED ( [username] ASC, [applicationname] ASC )WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY] ) ON [PRIMARY] One profile can have many affiliations. And one affiliation can have many profiles. And I would like to design it in such a way that relationships between affiliations tells me something about the associated profiles. In fact, based on the affiliations that users select, I would like to know how to infer as many things as possible about that person. My question is, how should I be designing my network affiliation tables and how do they operate per my above requirements? A rough SQL schema would be appreciated in your response. Thanks in advance...

    Read the article

  • Unnecessary Redundancy with Tables.

    - by Stacey
    My items are listed as follows; This is just a summary of course. But I'm using a method shown for the "Detail" table to represent a type of 'inheritence', so to speak - since "Item" and "Downloadable" are going to be identical except that each will have a few additional fields relevant only to them. My question is in this design pattern. This sort of thing appears many, many times in our projects - is there a more intelligent way to handle it? I basically need to normalize the tables as much as possible. I'm extremely new to databases and so this is all very confusing to me. There are 5 items. Awards, Items, Purchases, Tokens, and Downloads. They are all very, very similar, except each has a few pieces of data relevant only to itself. I've tried to use a declaration field (like an enumerator 'Type' field) in conjunction with nullable columns, but I was told that is a bad approach. What I have done is take everything similar and place it in a single table, and then each type has its own table that references a column in the 'base' table. The problem occurs with relationships, or junctions. Linking all of these back to a customer. Each type takes around 2 additional tables to properly junction all of the data together- and as such, my database is growing very, very large. Is there a smarter practice for this kind of behavior? Item ID | GUID Name | varchar(64) Product ID | GUID Name | varchar(64) Store | GUID [ FK ] Details | GUID [FK] Downloadable ID | GUID Name | varchar(64) Url | nvarchar(2048) Details | GUID [FK] Details ID | GUID Price | decimal Description | text Peripherals [ JUNCTION ] ID | GUID Detail | GUID [FK] Store ID | GUID Addresses | GUID Addresses ID | GUID Name | nvarchar(64) State | int [FK] ZipCode | int Address | nvarchar(64) State ID | int Name | varchar(32)

    Read the article

  • Common Properties: Consolidating Loan, Purchase, Inventory and Sale tables into one Transaction tabl

    - by Frank Computer
    Pawnshop Application: I have separate tables for Loan, Purchase, Inventory & Sales transactions. Each tables rows are joined to their respective customer rows by: customer.pk [serial] = loan.fk [integer]; = purchase.fk [integer]; = inventory.fk [integer]; = sale.fk [integer]; Since there are so many common properties within the four tables, I consolidated the four tables into one table called "transaction", where a column: transaction.trx_type char(1) {L=Loan, P=Purchase, I=Inventory, S=Sale} Scenario: A customer initially pawns merchandise, makes a couple of interest payments, then decides he wants to sell the merchandise to the pawnshop, who then places merchandise in Inventory and eventually sells it to another customer. I designed a generic transaction table where for example: transaction.main_amount DECIMAL(7,2) in a loan transaction holds the pawn amount, in a purchase holds the purchase price, in inventory and sale holds sale price. This is clearly a denormalized design, but has made programming alot easier and improved performance. Any type of transaction can now be performed from within one screen, without the need to change to different tables.

    Read the article

  • Extjs internet explorer object not found problem.

    - by john misoskian
    hi; this code run firefox , but error on ie why ? please help me. xxx.js code: var gridFormf = new Ext.FormPanel({ id: 'company-form', frame: true, labelAlign: 'left', title: 'Is Emri', bodyStyle:'padding:5px', width: 1, tbar: [ newIsEmri,delIsEmri,edIsEmri,rapIsEmri,serIsEmri ], layout: 'column', // Specifies that the items will now be arranged in columns items: [ { columnWidth: 0.3, layout: 'fit', items: [{ columnWidth: 1, xtype: 'fieldset', labelWidth: 90, title:'Ekip / Servis', defaults: {width: 120, border:false}, // Default config options for child items defaultType: 'textfield', autoHeight: true, bodyStyle: Ext.isIE ? 'padding:0 0 5px 15px;' : 'padding:10px 15px;', border: true, style: { "margin-left": "10px", // when you add custom margin in IE 6... "margin-right": Ext.isIE6 ? (Ext.isStrict ? "-10px" : "-13px") : "0" // you have to adjust for it somewhere else }, items: [{ fieldLabel: 'Ekip / Personel', name: 'SERVIS_VEREN' }] },{ columnWidth: 1, xtype: 'fieldset', labelWidth: 90, title:'Ürün', defaults: {width: 120, border:false}, // Default config options for child items defaultType: 'textfield', autoHeight: true, bodyStyle: Ext.isIE ? 'padding:0 0 5px 15px;' : 'padding:10px 15px;', border: true, style: { "margin-left": "10px", // when you add custom margin in IE 6... "margin-right": Ext.isIE6 ? (Ext.isStrict ? "-10px" : "-13px") : "0" // you have to adjust for it somewhere else }, items: [{ fieldLabel: 'Cihaz', name: 'URUN_CIHAZ_ADI' }, { fieldLabel: 'Marka', name: 'URUN_MARKA_ADI' }, { fieldLabel: 'Model', name: 'URUN_MODEL_ADI' },{ fieldLabel: 'Seri No', name: 'URUN_SERI_NO' } ] }] },{ columnWidth: 0.3, layout: 'fit', items: [{ columnWidth: 1, xtype: 'fieldset', labelWidth: 90, title: 'Servis Gelis Türü', defaults: { width: 140, border: false }, // Default config options for child items defaultType: 'textfield', autoHeight: true, bodyStyle: Ext.isIE ? 'padding:0 0 5px 15px;' : 'padding:10px 15px;', border: true, style: { "margin-left": "10px", // when you add custom margin in IE 6... "margin-right": Ext.isIE6 ? (Ext.isStrict ? "-10px" : "-13px") : "0" // you have to adjust for it somewhere else }, items: [{ fieldLabel: 'Gelis Türü', name: 'SERVIS_GELIS_TURU' }] },RadioPanels ] },{ columnWidth: 0.3, layout: 'fit', items: [{ columnWidth:1, autoHeight: true, border: true, items: [gridAksesuar] },gridAriza,{ columnWidth: 1, xtype: 'textarea', labelWidth: 0, width:250, defaultType: 'textarea', autoHeight: true, border: false, name:'ARIZA_ACIKLAMASI' }] },{ columnWidth: 1.0, layout: 'fit', items: gridFormx }] }); My html code : <script src="/ApplicationJs/xxx.js" type="text/javascript"></script> <script type="text/javascript"> Ext.onReady(function() { var viewport = new Ext.Viewport({ layout:'fit', items: [gridFormf] }); </script> Internet explorer return to error. Error description is object gridFormf is not found.

    Read the article

  • Using MVC2 to update an Entity Framework v4 object with foreign keys fails

    - by jbjon
    With the following simple relational database structure: An Order has one or more OrderItems, and each OrderItem has one OrderItemStatus. Entity Framework v4 is used to communicate with the database and entities have been generated from this schema. The Entities connection happens to be called EnumTestEntities in the example. The trimmed down version of the Order Repository class looks like this: public class OrderRepository { private EnumTestEntities entities = new EnumTestEntities(); // Query Methods public Order Get(int id) { return entities.Orders.SingleOrDefault(d => d.OrderID == id); } // Persistence public void Save() { entities.SaveChanges(); } } An MVC2 app uses Entity Framework models to drive the views. I'm using the EditorFor feature of MVC2 to drive the Edit view. When it comes to POSTing back any changes to the model, the following code is called: [HttpPost] public ActionResult Edit(int id, FormCollection formValues) { // Get the current Order out of the database by ID Order order = orderRepository.Get(id); var orderItems = order.OrderItems; try { // Update the Order from the values posted from the View UpdateModel(order, ""); // Without the ValueProvider suffix it does not attempt to update the order items UpdateModel(order.OrderItems, "OrderItems.OrderItems"); // All the Save() does is call SaveChanges() on the database context orderRepository.Save(); return RedirectToAction("Details", new { id = order.OrderID }); } catch (Exception e) { return View(order); // Inserted while debugging } } The second call to UpdateModel has a ValueProvider suffix which matches the auto-generated HTML input name prefixes that MVC2 has generated for the foreign key collection of OrderItems within the View. The call to SaveChanges() on the database context after updating the OrderItems collection of an Order using UpdateModel generates the following exception: "The operation failed: The relationship could not be changed because one or more of the foreign-key properties is non-nullable. When a change is made to a relationship, the related foreign-key property is set to a null value. If the foreign-key does not support null values, a new relationship must be defined, the foreign-key property must be assigned another non-null value, or the unrelated object must be deleted." When debugging through this code, I can still see that the EntityKeys are not null and seem to be the same value as they should be. This still happens when you are not changing any of the extracted Order details from the database. Also the entity connection to the database doesn't change between the act of Getting and the SaveChanges so it doesn't appear to be a Context issue either. Any ideas what might be causing this problem? I know EF4 has done work on foreign key properties but can anyone shed any light on how to use EF4 and MVC2 to make things easy to update; rather than having to populate each property manually. I had hoped the simplicity of EditorFor and DisplayFor would also extend to Controllers updating data. Thanks

    Read the article

  • WebClient error when using a thread in .NET

    - by Kiranu
    I'm having a very weird error using the WebClient class in .NET 4. The app simply downloads some files off the internet and provides output on a textbox (the GUI is WPF). The method that does this is the following: void DownloadFiles(object files) { fileL = (List<string>) files; foreach (string url in fileL) { byte[] data; using (System.Net.WebClient k = new WebClient()) { data = k.DownloadData(url); } //Bunch of irrelevant code goes here... } } (I added the using while trying to divine [yes I'm that desperate/ignorant] a solution, the problem happens even if the webclient is declared and initialized outside the foreach loop) Now the problem appears only when I'm executing this method on a thread separate from the WPF UI main thread. If it is executed on the UI thread then it works perfectly. When a new thread is created with: Thread t = new Thread(DownloadFiles); t.Start(files); The first time the code goes into the loop it will work, but when its the second pass inside the loop, I will always receive a TargetParameterCountException. I can't make any sense of this error. Any help is very much appreciated. EDIT Here are the Exception Details: Exception.Message = "Parameter count mismatch." Exception.InnerException = null Exception.Source = " mscorlib" The StackTrace follows: at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks) at System.Delegate.DynamicInvokeImpl(Object[] args) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs) at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler) at System.Windows.Threading.DispatcherOperation.InvokeImpl() at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state) at System.Threading.ExecutionContext.runTryCode(Object userData) at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData) at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Windows.Threading.DispatcherOperation.Invoke() at System.Windows.Threading.Dispatcher.ProcessQueue() at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled) at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled) at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs) at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler) at System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs) at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam) at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg) at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame) at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame) at System.Windows.Threading.Dispatcher.Run() at System.Windows.Application.RunDispatcher(Object ignore) at System.Windows.Application.RunInternal(Window window) at System.Windows.Application.Run(Window window) at System.Windows.Application.Run() at FileDownloader.App.Main() in d:\mis documentos\visual studio 2010\Projects\OneMangaDownloader\FileDownloader\obj\x86\Debug\App.g.cs:line 0 at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args) at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args) at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() at System.Threading.ThreadHelper.ThreadStart_Context(Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ThreadHelper.ThreadStart()

    Read the article

  • WebClient error when using a thread in .NET 4

    - by Kiranu
    I'm having a very weird error using the WebClient class in .NET 4. The app simply downloads some files off the internet and provides output on a textbox (the GUI is WPF). The method that does this is the following: void DownloadFiles(object files) { fileL = (List<string>) files; foreach (string url in fileL) { byte[] data; using (System.Net.WebClient k = new WebClient()) { data = k.DownloadData(url); } //Bunch of irrelevant code goes here... } } (I added the using while trying to divine [yes I'm that desperate/ignorant] a solution, the problem happens even if the webclient is declared and initialized outside the foreach loop) Now the problem appears only when I'm executing this method on a thread separate from the WPF UI main thread. If it is executed on the UI thread then it works perfectly. When a new thread is created with: Thread t = new Thread(DownloadFiles); t.Start(files); The first time the code goes into the loop it will work, but when its the second pass inside the loop, I will always receive a TargetParameterCountException. I can't make any sense of this error. Any help is very much appreciated. EDIT Here are the Exception Details: Exception.Message = "Parameter count mismatch." Exception.InnerException = null Exception.Source = " mscorlib" The StackTrace follows: at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks) at System.Delegate.DynamicInvokeImpl(Object[] args) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs) at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler) at System.Windows.Threading.DispatcherOperation.InvokeImpl() at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state) at System.Threading.ExecutionContext.runTryCode(Object userData) at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData) at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Windows.Threading.DispatcherOperation.Invoke() at System.Windows.Threading.Dispatcher.ProcessQueue() at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled) at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled) at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs) at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler) at System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs) at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam) at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg) at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame) at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame) at System.Windows.Threading.Dispatcher.Run() at System.Windows.Application.RunDispatcher(Object ignore) at System.Windows.Application.RunInternal(Window window) at System.Windows.Application.Run(Window window) at System.Windows.Application.Run() at FileDownloader.App.Main() in d:\mis documentos\visual studio 2010\Projects\OneMangaDownloader\FileDownloader\obj\x86\Debug\App.g.cs:line 0 at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args) at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args) at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() at System.Threading.ThreadHelper.ThreadStart_Context(Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ThreadHelper.ThreadStart()

    Read the article

  • TypeInitializeException on MVVM pattern

    - by Mohit Deshpande
    System.TypeInitializationException was unhandled Message=The type initializer for 'SmartHomeworkOrganizer.ViewModels.MainViewModel' threw an exception. Source=SmartHomeworkOrganizer TypeName=SmartHomeworkOrganizer.ViewModels.MainViewModel StackTrace: at SmartHomeworkOrganizer.ViewModels.MainViewModel..ctor() at SmartHomeworkOrganizer.App.OnStartup(Object sender, StartupEventArgs e) in C:\Users\Mohit\Documents\Visual Studio 2010\Projects\SmartHomeworkOrganizer\SmartHomeworkOrganizer\App.xaml.cs:line 21 at System.Windows.Application.OnStartup(StartupEventArgs e) at System.Windows.Application.<.ctor>b__0(Object unused) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Boolean isSingleParameter) at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler) at System.Windows.Threading.Dispatcher.WrappedInvoke(Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler) at System.Windows.Threading.DispatcherOperation.InvokeImpl() at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state) at System.Threading.ExecutionContext.runTryCode(Object userData) at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData) at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Windows.Threading.DispatcherOperation.Invoke() at System.Windows.Threading.Dispatcher.ProcessQueue() at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled) at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled) at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Boolean isSingleParameter) at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler) at System.Windows.Threading.Dispatcher.WrappedInvoke(Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler) at System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Boolean isSingleParameter) at System.Windows.Threading.Dispatcher.Invoke(DispatcherPriority priority, Delegate method, Object arg) at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam) at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg) at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame) at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame) at System.Windows.Threading.Dispatcher.Run() at System.Windows.Application.RunDispatcher(Object ignore) at System.Windows.Application.RunInternal(Window window) at System.Windows.Application.Run(Window window) at System.Windows.Application.Run() at SmartHomeworkOrganizer.App.Main() in C:\Users\Mohit\Documents\Visual Studio 2010\Projects\SmartHomeworkOrganizer\SmartHomeworkOrganizer\obj\Debug\App.g.cs:line 0 at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args) at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args) at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() at System.Threading.ThreadHelper.ThreadStart_Context(Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ThreadHelper.ThreadStart() InnerException: System.ArgumentException Message=Default value type does not match type of property 'Score'. Source=WindowsBase StackTrace: at System.Windows.DependencyProperty.ValidateDefaultValueCommon(Object defaultValue, Type propertyType, String propertyName, ValidateValueCallback validateValueCallback, Boolean checkThreadAffinity) at System.Windows.DependencyProperty.ValidateMetadataDefaultValue(PropertyMetadata defaultMetadata, Type propertyType, String propertyName, ValidateValueCallback validateValueCallback) at System.Windows.DependencyProperty.RegisterCommon(String name, Type propertyType, Type ownerType, PropertyMetadata defaultMetadata, ValidateValueCallback validateValueCallback) at System.Windows.DependencyProperty.Register(String name, Type propertyType, Type ownerType, PropertyMetadata typeMetadata, ValidateValueCallback validateValueCallback) at System.Windows.DependencyProperty.Register(String name, Type propertyType, Type ownerType, PropertyMetadata typeMetadata) at SmartHomeworkOrganizer.ViewModels.MainViewModel..cctor() in C:\Users\Mohit\Documents\Visual Studio 2010\Projects\SmartHomeworkOrganizer\SmartHomeworkOrganizer\ViewModels\MainViewModel.cs:line 72 InnerException: This bit of code throws a System.ArgumentException before the TypeInitializeException. It says: "Default value type does not match type of property Score": public static readonly DependencyProperty ScoreProperty = DependencyProperty.Register("Score", typeof(float), typeof(MainViewModel), new UIPropertyMetadata(0.0)); Here is the .NET property: public float Score { get { return (float) GetValue(ScoreProperty); } set { SetValue(ScoreProperty, value); } }

    Read the article

  • Eclipselink read complex object model in an ordered way

    - by Raven
    Hi, I need to read a complex model in an ordered way with eclipselink. The order is mandantory because it is a huge database and I want to have an output of a small portion of the database in a jface tableview. Trying to reorder it in the loading/quering thread takes too long and ordering it in the LabelProvider blocks the UI thread too much time, so I thought if Eclipselink could be used that way, that the database will order it, it might give me the performance I need. Unfortunately the object model can not be changed :-( The model is something like: @SuppressWarnings("serial") @Entity public class Thing implements Serializable { @Id @GeneratedValue(strategy = GenerationType.TABLE) private int id; private String name; @OneToMany(cascade=CascadeType.ALL) @PrivateOwned private List<Property> properties = new ArrayList<Property>(); ... // getter and setter following here } public class Property implements Serializable { @Id @GeneratedValue(strategy = GenerationType.TABLE) private int id; @OneToOne private Item item; private String value; ... // getter and setter following here } public class Item implements Serializable { @Id @GeneratedValue(strategy = GenerationType.TABLE) private int id; private String name; .... // getter and setter following here } // Code end In the table view the y-axis is more or less created with the query Query q = em.createQuery("SELECT m FROM Thing m ORDER BY m.name ASC"); using the "name" attribute from the Thing objects as label. In the table view the x-axis is more or less created with the query Query q = em.createQuery("SELECT m FROM Item m ORDER BY m.name ASC"); using the "name" attribute from the Item objects as label. Each cell has the value Things.getProperties().get[x].getValue() Unfortunately the list "properties" is not ordered, so the combination of cell value and x-axis column number (x) is not necessarily correct. Therefore I need to order the list "properties" in the same way as I ordered the labeling of the x-axis. And exactly this is the thing I dont know how it is done. So querying for the Thing objects should return the list "properties" "ORDER BY name ASC" but of the "Item"s objects. My ideas are something like having a query with two JOINs. Joing Things with Property and with Item but somehow I was unable to get it to work yet. Thank you for your help and your ideas to solve this riddle.

    Read the article

  • How to Access a decendant object's internal method in C#

    - by Giovanni Galbo
    I'm trying to access a method that is marked as internal in the parent class (in its own assembly) in an object that inherits from the same parent. Let me explain what I'm trying to do... I want to create Service classes that return IEnumberable with an underlying List to non-Service classes (e.g. the UI) and optionally return an IEnumerable with an underlying IQueryable to other services. I wrote some sample code to demonstrate what I'm trying to accomplish, shown below. The example is not real life, so please remember that when commenting. All services would inherit from something like this (only relevant code shown): public class ServiceBase<T> { protected readonly ObjectContext _context; protected string _setName = String.Empty; public ServiceBase(ObjectContext context) { _context = context; } public IEnumerable<T> GetAll() { return GetAll(false); } //These are not the correct access modifiers.. I want something //that is accessible to children classes AND between descendant classes internal protected IEnumerable<T> GetAll(bool returnQueryable) { var query = _context.CreateQuery<T>(GetSetName()); if(returnQueryable) { return query; } else { return query.ToList(); } } private string GetSetName() { //Some code... return _setName; } } Inherited services would look like this: public class EmployeeService : ServiceBase<Employees> { public EmployeeService(ObjectContext context) : base(context) { } } public class DepartmentService : ServiceBase<Departments> { private readonly EmployeeService _employeeService; public DepartmentService(ObjectContext context, EmployeeService employeeService) : base(context) { _employeeService = employeeService; } public IList<Departments> DoSomethingWithEmployees(string lastName) { //won't work because method with this signature is not visible to this class var emps = _employeeService.GetAll(true); //more code... } } Because the parent class lives is reusable, it would live in a different assembly than the child services. With GetAll(bool returnQueryable) being marked internal, the children would not be able to see each other's GetAll(bool) method, just the public GetAll() method. I know that I can add a new internal GetAll method to each service (or perhaps an intermediary parent class within the same assembly) so that each child service within the assembly can see each other's method; but it seems unnecessary since the functionality is already available in the parent class. For example: internal IEnumerable<Employees> GetAll(bool returnIQueryable) { return base.GetAll(returnIQueryable); } Essentially what I want is for services to be able to access other service methods as IQueryable so that they can further refine the uncommitted results, while everyone else gets plain old lists. Any ideas?

    Read the article

  • objective-c uncompress/inflate a NSData object which contains a gzipped string

    - by user141146
    Hi, I'm using objective-c (iPhone) to read a sqlite table that contains blob data. The blob data is actually a gzipped string. The blob data is read into memory as an NSData object I then use a method (gzipInflate) which I grabbed from here (http://www.cocoadev.com/index.pl?NSDataCategory) -- see method below. However, the gzipInflate method is returning nil. If I step through the gzipInflate method, I can see that the status returned near the bottom of the method is -3, which I assume is some type of error (Z_STREAM_END = 1 and Z_OK = 0, but I don't know precisely what a status of -3 is). Consequently, the function returns nil even though the input NSData is 841 bytes in length. Any thoughts on what I'm doing wrong? Is there something wrong with the method? Something wrong with how I'm using the method? Any thoughts on how to test this? Thanks for any help! - (NSData *)gzipInflate { // NSData *compressed_data = [self.description dataUsingEncoding: NSUTF16StringEncoding]; NSData *compressed_data = self.description; if ([compressed_data length] == 0) return compressed_data; unsigned full_length = [compressed_data length]; unsigned half_length = [compressed_data length] / 2; NSMutableData *decompressed = [NSMutableData dataWithLength: full_length + half_length]; BOOL done = NO; int status; z_stream strm; strm.next_in = (Bytef *)[compressed_data bytes]; strm.avail_in = [compressed_data length]; strm.total_out = 0; strm.zalloc = Z_NULL; strm.zfree = Z_NULL; if (inflateInit2(&strm, (15+32)) != Z_OK) return nil; while (!done) { // Make sure we have enough room and reset the lengths. if (strm.total_out >= [decompressed length]) [decompressed increaseLengthBy: half_length]; strm.next_out = [decompressed mutableBytes] + strm.total_out; strm.avail_out = [decompressed length] - strm.total_out; // Inflate another chunk. status = inflate (&strm, Z_SYNC_FLUSH); NSLog(@"zstreamend = %d", Z_STREAM_END); if (status == Z_STREAM_END) done = YES; else if (status != Z_OK) break; //status here actually is -3 } if (inflateEnd (&strm) != Z_OK) return nil; // Set real length. if (done) { [decompressed setLength: strm.total_out]; return [NSData dataWithData: decompressed]; } else return nil; }

    Read the article

< Previous Page | 312 313 314 315 316 317 318 319 320 321 322 323  | Next Page >