pdf417 c# open source Continued in visual C#.net

Make PDF 417 in visual C#.net Continued

In Par allel (sec on ds)

associated with the property, thus providing all the information needed to invoke the rule when appropriate. In fact, the RuleMethod object handles the invocation of the rule method itself by exposing an Invoke() method: Public Function Invoke() As Boolean Return mHandler.Invoke(mTarget, mArgs) End Function When ValidationRules is asked to check the business rules, it merely loops through its list of RuleMethod objects, asking each one to invoke the rule it represents. As you can see, the Invoke() method simply invokes the method via the delegate reference, passing in a reference to the object to be validated (the business object) and the RuleArgs object associated with the rule.

Instance members come into existence when the instance is created, and go out of existence when the instance is destroyed. Static members, however, exist and are accessible even if there are no instances of the class. Figure 6-4 illustrates a class D, with a static field, Mem2. Although Main does not define any instances of the class, it assigns the value 5 to the static field and prints it out.

Unless the database server is getting overwhelmed with connections from the web servers in the web farm, a separate application server will rarely provide gains in scalability. If a separate application server is needed, there will be a reduction in performance because of the additional physical tier. (Hopefully, there will be a gain in scalability, because the application server can consolidate database connections across all the web servers.) It is important to consider fault tolerance in this case, because redundant application servers may be needed in order to avoid a point of failure. Another reason for implementing an application server is to increase security, and that s the topic of the next section.

What are the benefits of shared server, bearing in mind that you have to be somewhat careful about the transaction types you let use it Shared server does three things: it reduces the number of operating system processes/threads, it artificially limits the degree of concurrency, and it reduces the memory needed on the system. Let s discuss these points in more detail.

void NormalizeVector(const Vector3D *inVec, Vector3D *result) { float length = sqrt((inVec->x * inVec->x) + (inVec->y * inVec->y) + (inVec->z * inVec->z)); float oneOverLength = 1.0f/length; result->x = inVec->x * oneOverLength; result->y = inVec->y * oneOverLength; result->z = inVec->z * oneOverLength; }

The declaration of Book is an immutable object. Or at least Book is immutable to any class that isn t Book, as the set part of the properties have been declared private. So let s say the contents of Book need to be updated, which means creating a new object because of the immutability. A new object is instantiated and added to the NHibernate session. NHibernate will be confused because there are two object instances with the same primary keys. To get around this problem, the only real option is to delete the object from the relational database, and then add the object again. Following is the source code to delete the object: ITransaction transaction = _session.BeginTransaction(); Book myBook = (Book)_session.Load(typeof(Book), "1-59059-540-8"); _session.Delete( myBook); transaction.Commit();