Common points of confusion in visual basic

Encoder Data Matrix in visual basic Common points of confusion

In a very short amount of time, the App store has exploded in volume. There are Apps for just about anything you can imagine. Apps come in all prices, and, in many cases are free.

The Binding class gives you the ability to determine how data can flow between the source and the target. This flow can be controlled by setting the Binding instance s Mode property. This property represents one of the three options available in the BindingMode enumerator OneTime, OneWay, and TwoWay.

This chapter covered a wide range of topics, from #include files to linked lists. The intent of the chapter, however, was to attack a real-world programming problem in this case, a program to catalog DVDs. This chapter showed several design approaches, discussing the pros and cons of each. Finally, the chapter presented a prototype for a DVD-tracking program. The program allows you to enter information about a series of DVDs and, on request, will present a list of all the DVDs tracked. One problem with this program is that once you exit, all of the data you entered is lost. The next time you run the program, you have to start all over again. 10 offers a solution to this problem. The chapter introduces the concept of files and file management, showing you how to save your data from memory out to your hard disk drive and how to read your data back in again. The next chapter updates dvdTracker, storing the DVD information collected in a file on your disk drive.

Figure 7.5 The Processors page of the Server Properties window allows changes to CPU configuration settings: CPU Affinity, Maximum Worker Threads, Boost SQL Server Priority, and Use Windows Fibers (Lightweight Pooling).

It didn t work out as expected, though. The network connection received 1,440 bytes at a time, so initially the audio player couldn t be created because there weren t enough bytes in the data object. Buffering wouldn t make the situation any better though, because AVAudioPlayer reads audio file length from the audio file header and then crashes if it can t read to the end. The end result is that the only buffer that s big enough is one that s at least as big as the file being played, which effectively means that playing during download is impossible.

Once you install the spGetTerritory stored procedure, be sure to grant EXECUTE permissions to the database login that the AW Shared DS shared data source uses. The spGetTerritory procedure retrieves the list of the sales territories that have orders placed in a given year, as shown here:

I mention the Microsoft.ReportingServices.DataExtensions assembly for completeness only. You don t need to reference it explicitly in your BI project.

This code fragment uses three #defines. kMaxDVDs defines the maximum number of DVDs this program will track. kMaxTitleLength defines the maximum length of a DVD title. kMaxCommentLength defines the maximum length of a DVD comment.

Consider this frequently asked question: I get an OutOfMemoryException when I try to load 100,000 objects and manipulate all of them. How can I do mass updates with NHibernate It s our view that ORM isn t suitable for mass-update (or mass-delete) operations. If you have a use case like this, a different strategy is almost always better: call a stored procedure in the database, or use direct SQL UPDATE and DELETE statements for that particular use case. Don t transfer all the data to main memory for a simple operation if it can be performed more efficiently by the database. If your application is mostly mass-operation use cases, ORM isn t the right tool for the job! If you insist on using NHibernate for mass operations, you can immediately Evict() each object after it has been processed (while iterating through a query result), and thus prevent memory exhaustion. To completely evict all objects from the session cache, call Session.Clear(). We aren t trying to convince you that evicting objects from the first-level cache is a bad thing in general, but that good use cases are rare. Sometimes, using projection and a report query, as discussed in section 8.4.5, may be a better solution. Note that eviction, like save or delete operations, can be automatically applied to associated objects. NHibernate evicts associated instances from the ISession if the mapping attribute cascade is set to all or all-delete-orphan for a particular association. When a first-level cache miss occurs, NHibernate tries again with the second-level cache if it s enabled for a particular class or association.

Under Project Types, A list of C# Templates appears. select Visual C# Projects. Under Templates, select Windows Application. In the Name field, enter MyPhotos . Note: The Location entry may vary depending on which version of Windows you are using. To avoid any confusion, this book will use the directory C:\Windows Forms\Projects. In your code, use the default setting provided by the environment.

A persistent instance is any instance with a database identity, as defined in section 3.5. That means a persistent object has a primary key value set as its database identifier. Persistent instances might be objects instantiated by the application and then made persistent by calling the Save() method of the persistence manager (the NHibernate ISession, discussed in more detail later in this chapter). Persistent instances are then associated with the persistence manager. They might even be objects that became persistent when a reference was created from another persistent object already associated with a persistence manager. Alternatively, a persistent instance might be an instance retrieved from the database by execution of a query, by an identifier lookup, or by navigating the object graph starting from another persistent instance. In other words, persistent instances are always associated with an ISession and are transactional. Persistent instances participate in transactions their state is synchronized with the database at the end of the transaction. When a transaction commits, state held in memory is propagated to the database by the execution of SQL INSERT, UPDATE, and DELETE statements. This procedure can also occur at other times. For example, NHibernate may synchronize with the database before execution of a query. This ensures that queries are aware of changes made earlier during the transaction. We call a persistent instance new if it has been allocated a primary key value but hasn t yet been inserted into the database. The new persistent instance will remain new until synchronization occurs.

Enter your Apple ID and password or click I do not have an Apple ID and select your country. Then click the Continue button. If you tried to enter your Apple ID and password and received an error message about additional security information is required, then read the Troubleshooting: Fixing the Apple ID Security Error section in 30, iTunes User Guide.

SCM stands for Source Code Management, more commonly known as version control. Xcode has powerful support tools for managing version control of code in your projects, and whether you are coding as part of a project team or solo, good version control will undoubtedly save your skin one of these days, so it s a good practice to adopt. You will learn all about Xcode s SCM tools in 9. The SCM section is empty and will remain so until you have put your project under source control; from then on you will see any project components that need attention from a source control point of view.