Figure 5 11. The MUGsub application running, showing the To-Many relationship in Objective-C

Drawer Data Matrix 2d barcode in Objective-C Figure 5 11. The MUGsub application running, showing the To-Many relationship

Figure 5 11. The MUGsub application running, showing the To-Many relationship
Painting ECC200 In Objective-C
Using Barcode printer for iPhone Control to generate, create ECC200 image in iPhone applications.
www.OnBarcode.com
Encoding UCC - 12 In Objective-C
Using Barcode maker for iPhone Control to generate, create EAN 128 image in iPhone applications.
www.OnBarcode.com
CHAPTER 5: Frameworks in Xcode
Barcode Printer In Objective-C
Using Barcode maker for iPhone Control to generate, create Barcode image in iPhone applications.
www.OnBarcode.com
UPC-A Supplement 2 Creation In Objective-C
Using Barcode encoder for iPhone Control to generate, create GTIN - 12 image in iPhone applications.
www.OnBarcode.com
A Potential Gotcha
Barcode Creator In Objective-C
Using Barcode drawer for iPhone Control to generate, create Barcode image in iPhone applications.
www.OnBarcode.com
Generate Data Matrix In Objective-C
Using Barcode drawer for iPhone Control to generate, create Data Matrix ECC200 image in iPhone applications.
www.OnBarcode.com
As you work with a data model in Core Data you may find yourself suddenly confronted with this error message on running the program:
EAN13 Generator In Objective-C
Using Barcode creation for iPhone Control to generate, create EAN / UCC - 13 image in iPhone applications.
www.OnBarcode.com
Draw UPC-E In Objective-C
Using Barcode generator for iPhone Control to generate, create UPC-E Supplement 2 image in iPhone applications.
www.OnBarcode.com
"The model configuration used to open the store is incompatible with the one that was used to create the store."
Create DataMatrix In Visual Basic .NET
Using Barcode creator for .NET framework Control to generate, create Data Matrix image in VS .NET applications.
www.OnBarcode.com
Data Matrix 2d Barcode Maker In None
Using Barcode encoder for Online Control to generate, create Data Matrix 2d barcode image in Online applications.
www.OnBarcode.com
While alarming, this error message is easily sorted out. By default, Core Data stores its data in an XML file (there are other storage options and you will cover those later). If you have changed the data model, the version stored the first time you ran the program may be different to the current storage structure. Hence this message your program doesn t understand the structure of the data store. The solution is simply to find the persistent store (by default this will be ~/Library/Application Support/[your application name]/storedata and just delete the file. Go ahead it will be regenerated the next time you run the program (of course, you will lose any data in the store, sadly). There is an alternative, which you might like to investigate if the data is too important to lose. Xcode provides migration tools to allow you to migrate data from one version of a data model to another. Search the Developer Documentation for Core Data Migration or look here: http://developer.apple.com/mac/library/documentation/Cocoa/Conceptual/CoreDataV ersioning/Introduction/Introduction.html. This is a quite advanced topic and you should aim to be comfortable with Core Data programming before investigating it indepth.
PDF-417 2d Barcode Printer In .NET Framework
Using Barcode encoder for ASP.NET Control to generate, create PDF-417 2d barcode image in ASP.NET applications.
www.OnBarcode.com
QR Code 2d Barcode Drawer In None
Using Barcode drawer for Font Control to generate, create QR Code JIS X 0510 image in Font applications.
www.OnBarcode.com
Choosing a Data Store
UPCA Drawer In None
Using Barcode generator for Office Word Control to generate, create GS1 - 12 image in Office Word applications.
www.OnBarcode.com
Code 128 Generation In Visual Basic .NET
Using Barcode printer for Visual Studio .NET Control to generate, create Code 128 Code Set C image in VS .NET applications.
www.OnBarcode.com
You may be wondering where your database is located. Nothing in this example so far has indicated how or where your data is being stored. In fact, Core Data gives you a degree of choice about this. By default, your data is stored as an XML file in the location ~/Library/Application Support/[your application name]/storedata as mentioned in the previous section, A Potential Gotcha. However, you also have the option to store it in SQLite or binary formats. Here s how. Look in the file MUG_AppDelegate.m and find the method called persistentStoreCoordinator. In Listing 5 1 you will see the significant code fragment:
Barcode Maker In .NET Framework
Using Barcode generation for VS .NET Control to generate, create Barcode image in .NET applications.
www.OnBarcode.com
Creating Barcode In Java
Using Barcode creator for Java Control to generate, create Barcode image in Java applications.
www.OnBarcode.com
Listing 5 1. Setting the Storage Options for a Core Data Application NSURL *url = [NSURL fileURLWithPath: [applicationSupportDirectory stringByAppendingPathComponent: @"storedata"]]; persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel: mom]; if (![persistentStoreCoordinator addPersistentStoreWithType:NSXMLStoreType configuration:nil URL:url
Read Barcode In Java
Using Barcode Control SDK for Java Control to generate, create, read, scan barcode image in Java applications.
www.OnBarcode.com
Making GTIN - 13 In None
Using Barcode generation for Font Control to generate, create EAN13 image in Font applications.
www.OnBarcode.com
CHAPTER 5: Frameworks in Xcode
Recognize QR In Visual C#.NET
Using Barcode scanner for Visual Studio .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
Drawing QR In None
Using Barcode generation for Microsoft Word Control to generate, create QR Code ISO/IEC18004 image in Office Word applications.
www.OnBarcode.com
options:nil error:&error]){ [[NSApplication sharedApplication] presentError:error]; [persistentStoreCoordinator release], persistentStoreCoordinator = nil; return nil; }
The first bold section shows the file name used to store your data. You can actually give this any name you like: a.b, for example. The second bold section is where you choose the storage format. Your choices are NSXMLStoreType (the default, as an XML file), NSSQLiteStoreType (for a SQLite database) or NSBinaryStoreType (for the more traditional binary data format used for Mac OS X data stores before the days of Core Data). The Core Data framework is a very large and complex component of Cocoa, and you have barely scratched the surface here. You will return to Core Data programming in much more depth in 9.
The ScreenSaver Framework
Screen savers in Mac OS X, like in other operating systems, are normal applications, but with some additional features that allow them to fit into the screen saver mechanism that is managed within System Preferences. In this section, you are going to build a screen saver that makes use of the OpenGL drawing framework. I make no pretence of being an OpenGL developer, by the way. The example that you will follow here draws on some great resources, notably the chapter on OpenGL programming in Aaron Hillegass s master work Cocoa Programming for Mac OS X, 3rd Edition, and also the excellent articles by Brian Christensen on the Cocoa Dev Central website (www.cocoadevcentral.com). The code here should be easy to follow, but you can get more detail on the underlying code in these and other resources. You are going to create a screen saver that shows the famous OpenGL teapot. When it is complete the screen saver will look like this (see Figure 5 12). You start in the by now familiar way, although unlike most Cocoa projects you are not going to use Interface Builder in this example. In Xcode, choose a new project. This time choose the System Plug-in item in the User templates list and select Screen Saver. Give the project the name TumblingTeapot . You will see the usual Xcode project window, but notice the ScreenSaver.framework item in the detail list. Take a look at the structure of your class (TumblingTeapot.m). All of the basic routines for your screensaver are already there. In fact, this is already a working screensaver. If you really wanted, you could build this and install it. Of course, all it would do is give you a blank screen, but if you should ever want a simple blank screen saver, this is one way to do it!
Copyright © OnBarcode.com . All rights reserved.