dot net qr code library Delivering Your BBP Presentation in visual basic.net

Deploy qr codes in visual basic.net Delivering Your BBP Presentation

. 1 . . Start Visual Studio .NET by clicking New, Project on the main menu . In the New Project dialog box, click Console Application and name the application WebRequestorApp, as shown in the following graphic:

Part I:

20 10 30 20 30 20 10

In many tools such as the tokens shown in Process Explorer privileges show up in a different format than they do in Group Policy. Table 3-7 shows both strings for all privileges,

Protocol==ARP Dom1(IP) Client26(IP)

A chain of routines passes tramp data Finding yourself passing data to one routine just so that routine can pass it to another routine is called tramp data (Page-Jones 1988). This might be OK, or it might not. Ask whether passing the specific data in question is consistent with the abstraction presented by each of the routine interfaces. If the abstraction for each routine is OK, passing the data is OK. If not, find some way to make each routine s interface more consistent. A middle man object isn t doing anything If you find that most of the code in a class is just passing off calls to routines in other classes, consider whether you should eliminate the middleman and call those other classes directly. One class is overly intimate with another Encapsulation (information hiding) is probably the strongest tool you have to make your program intellectually manageable and to minimize ripple effects of code changes. Anytime you see one class that knows more about another class than it should (including derived classes knowing too much about their parents), err on the side of stronger encapsulation rather than weaker. A routine has a poor name If a routine has a poor name, change the name of the routine where it s defined, change the name in all places it s called, and then recompile. As hard as it might be to do this now, it will be even harder later, so do it as soon as you notice it s a problem. Data members are public Public data members are, in my view, always a bad idea. They blur the line between interface and implementation. They inherently violate encapsulation and limit future flexibility. Strongly consider hiding public data members behind access routines. A subclass uses only a small percentage of its parents routines Typically this indicates that that subclass has been created because a parent class happened to contain the routines it needed, not because the subclass is logically a descendent of the superclass. Consider achieving better encapsulation by switching the subclass s relationship to its superclass from an is-a relationship to a has-a relationship; convert the superclass to member data of the former subclass and expose only the routines in the former subclass that are really needed. Comments are used to explain difficult code Comments have an important role to play, but they should not be used as a crutch to explain bad code. The age-old wisdom is dead on: Don t document bad code rewrite it (Kernighan and Plauger 1978).

So far in this chapter, the use of delegates has required the developer to know up front the prototype of the method that is to be called back . For example, if fb is a variable that references a Feedback delegate (see this chapter s first program listing), to invoke the delegate, the code would look like this:

Note: You could use separate worker roles, one to calculate and save the summary statistics, and one to save the survey results to table storage if you need to scale the application. There is an 8-kilobyte (KB) maximum size for a message on a Windows Azure queue, so this approach works only if the size of each survey response is less than that maximum. Figure 3 shows how you could modify this solution to handle survey results that are greater than 8 KB in size.

Listing 8-24. Count Employees Per Department (Third Attempt) select deptno, count(e.empno) from employees e right outer join departments d using (deptno) group by deptno; DEPTNO COUNT(E.EMPNO) -------- -------------10 3 20 5 30 6 40 0 At the end of 5, you saw an example of a PL/SQL stored function to count all employees per department (Section 5.8, Listing 5-31). In that chapter, I mentioned that this counting problem is not trivial to solve in standard SQL. In Listings 8-22, 8-23, and 8-24, you see that you should indeed be careful. You need an outer join, and you should make sure to specify the correct argument for the COUNT function to get correct results.