c# print barcode zebra printer Figure 5-6. The minigolf game layer with player sprites rotated based on their angles to the center in Objective-C

Generation data matrix barcodes in Objective-C Figure 5-6. The minigolf game layer with player sprites rotated based on their angles to the center

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would be closer to object-oriented platforms and imperative programming languages such as C# and VB.NET. However, after all these years, relational databases are still pervasive, and you still have to struggle with data access and persistence in all of your programs. The original motivation behind LINQ was to address the conceptual and technical difficulties encountered when using databases with .NET programming languages. With LINQ, Microsoft s intention was to provide a solution for the problem of object-relational mapping, as well as to simplify the interaction between objects and data sources. LINQ eventually evolved into a general-purpose language-integrated querying toolset. This toolset can be used to access data coming from in-memory objects (LINQ to Objects), databases (LINQ to SQL), XML documents (LINQ to XML), a file-system, or any other source. We will first give you an overview of what LINQ is, before looking at the tools it offers. We will also introduce how LINQ extends programming languages.

Don t forget to start SQL Server again when you re done. Also, if you re editing the code as we go, you can delete the Bank.Main method which we inserted for testing purposes.

Because the Data Profiling task uses connection managers to control the connection to the database, it is relatively easy to change the database it points to. You update the connection manager, using one of the standard approaches in SSIS, such as an expression that sets the ConnectionString property, or a configuration that sets the same property. You can also accomplish this by overriding the connection manager s setting at runtime using the /Connection switch of DTEXEC. Bear in mind that although you can switch databases this way, the task will only work if it is pointing to a SQL Server database. Also, connection managers only control the database that you are connecting to, and not the specific tables. The profile requests in the task will still be referencing the original tables, so if the new database does not contain tables with the same names, the task will fail. What is needed is a way to change the profile requests to reference new tables.

Listing 7.7 A method executed by a thread that increments a value NumberOfIterations (C#)

The Model-View-Controller design pattern is one of the most important design patterns in computer science. Whereas most patterns address specific problems, Model-View-Controller (MVC) describes the architecture of a system of objects. It can be applied to isolated subsystems or entire applications. The Model-View-Controller design pattern is also less clearly defined than many other patterns, leaving a lot of latitude for alternate implementations. It s more a philosophy than a recipe. A clear understanding of MVC is critical to using Cocoa, because the entire Cocoa framework is designed around the Model-View-Controller design pattern (where applicable). Where Java adopts MVC for many tasks, Cocoa passionately embraces it. MVC is the soul of Cocoa. Designing with MVC will smooth your development, since so many of the framework objects are designed to integrate effortlessly with an MVC design. Befitting a broad design pattern, this is an expansive chapter that touches on a wide range of classes and technologies. (It wouldn t be very useful if it merely described the MVC design pattern something you re probably already familiar with, anyway). To be practical, each section not only describes design concepts but goes on to explore the classes, protocols, frameworks, and development tools that you ll use to implement those concepts. For example, this chapter begins with the basic MVC design principles, and then goes on to describe bindings (a technology used to implement MVC communications) and Interface Builder (a development tool used to connect MVC objects). The section on view objects explains the role of view objects, and then goes on to explain how to use pre-built view objects, how to create your own view objects, how those view objects draw themselves, and the basics of the Cocoa graphics environment. The sections on data model objects describe not only the conceptual role of data model objects, but some of the classes and development tools that can be used to create complex data models. In short, this is a really long chapter, so settle in and take your time. You should be comfortable with each concept before moving on to the next. To help you put each piece into perspective, I ve created a simple Cocoa application that plays Tic Tac Toe. It s a relatively small project that touches on most of the topics in this chapter, and will be used to illustrate many of them. I recommend that you download the project from the Source Code/Downloads section of http://www.apress.com so you can see how each concept fits into the whole. There is also a section on Interface Builder, a key Cocoa development tool, and how it supports the MVC design pattern. At the end of this chapter is a brief section that describes some noteworthy aspects of the project that aren t covered elsewhere. Model-View-Controller sits atop a broad base of supporting technologies, at the apex of the design pyramid. To master MVC, you need a firm grasp of the technologies that support it. You should be familiar with, or review, the following before attempting to tackle MVC in Cocoa: Objective-C Messages ( 6) Informal Protocols ( 5) Delegates ( 17) Key-Value Coding ( 10) Key-Value Observing ( 19)

By using [self getChildByTag:13], you can access the CCLabel object by its tag property, which you assigned in the init method. You can then use the label as usual. In this case, we use cocos2d s handy CCRANDOM_0_1() macro to change the label s scale

This searches through the registry starting at the classes root, where COM objects are registered for keys whose paths end in ProgID . From the keys, we retrieve the

PowerShell cmdlets return collections of data. In many ways, these collections are like data tables . Sometimes we need to combine fields from two collections to produce a new object that includes properties from objects from each of the collections. In effect, what we need to do is execute a join across the two datasets. A real-world scenario where this occurred was a customer who needed to export a list of mailbox users from an Exchange server to a CSV file, but also needed to merge in some additional data about each user that was stored in a separate CSV file. While PowerShell V1 doesn t have built-in tools to do this, it s easy to do using hashtables. Here s the basic solution. Get the first set of data into a hashtable indexed by the primary key property. Then traverse the second set, adding in the additional properties extracted from the hashtable. (Or create new objects and add properties from both sets.) Here s an example showing how to do this. It merges properties from collections of Process and ServiceController objects into a single object, and then exports the joined result as a CSV file:

User user = (User) session.Get(typeof(User), userID);