c# ean 13 check digit de Complete in C#.NET

Drawer EAN-13 in C#.NET de Complete

performed carefully, part of the care being clear documentation. As usual, if documenting becomes too onerous, rewrite the code to reduce the use of global data.

Document the source of algorithms that are used If you have used an algorithm from a book or magazine, document the volume and page number you took it from. If you developed the algorithm yourself, indicate where the reader can find the notes you ve made about it. Use comments to mark parts of your program Some programmers use comments to mark parts of their program so that they can find them easily. One such technique in C++ and Java is to mark the top of each routine with a comment such as

This allows you to jump from routine to routine by doing a string search for /**. A similar technique is to mark different kinds of comments differently, depending on what they describe. For example, in C++ you could use @keyword, where keyword is a code you use to indicate the kind of comment. The comment @param could indicate that the comment describes a parameter to a routine, @version could indicate file-version information, @throws could document the exceptions thrown by a routine, and so on. This technique allows you to use tools to extract different kinds of information from your source files. For example, you could search for @throws to retrieve documentation about all of the exceptions thrown by all of the routines in a program. This C++ convention is based on the JavaDoc convention, which is a wellestablished interface documentation convention for Java programs (java.sun.com/j2se/javadoc/). You can define your own conventions in other languages.

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For layout details, see Section 31.8, "Laying Out Classes." For details on using classes, see 6, "Working Classes."

Classes, files, and programs are all characterized by the fact that they contain multiple routines. A file or class should contain a collection of related routines. A program contains all the routines in a program. The documentation task in each case is to provide a meaningful, top-level view of the contents of the file, class, or program. The issues are similar in each case, so I ll just refer to documenting files, and you can assume that the guidelines apply to classes and programs as well.

Describe the design approach to the class Overview comments that provide information that can t readily be reverse engineered from coding details are especially useful. Describe the class s design philosophy, overall design approach, design alternatives that were considered and discarded, and so on. Describe limitations, usage assumptions, and so on Similar to routines, be sure to describe any limitations imposed by the class s design. Also describe assumptions about input and output data, error-handling responsibilities, global effects, sources of algorithms, and so on. Comment the class interface Can another programmer understand how to use a class without looking at the class s implementation If not, then class encapsulation is seriously at risk. The class s interface should contain all the information anyone needs to use the class. The JavaDoc convention is to require, at a minimum, documentation for each parameter and each return value (Sun Microsystems 2000). This should be done for all exposed routines of each class (Bloch 2001). Don t document implementation details in the class interface A cardinal rule of encapsulation is that you expose information only on a needto-know basis: if there is any question about whether information needs to be exposed, the default is to keep it hidden. Consequently, class interface files should contain information needed to use the class, but not information needed to implement or maintain the inner workings of the class.