Home > Articles > Programming > General Programming/Other Languages

  • Print
  • + Share This
This chapter is from the book

1.7 COBOL Classes and the .NET Base Classes

We have seen above how the different .NET-enabled languages can inherit and communicate with each other. This is a powerful feature of the .NET Framework, however, the real power for the developer in developing new applications is in the thousands of .NET base classes available. Using these base classes is how the programmer communicates with the Common Language Runtime (CLR), which then controls the powerful operating system engine. The CLR works with an extensive set of Win32 APIs to implement the functionality desired. Figure 1–7 shows this diagram of the layers of classes.

Figure 1-7Figure 1–7 Class Layers

Let's look at an example of using several of the .NET base classes by a COBOL program. The WalkTheDog example is on the FTP site. The program is WalkTheDog.cob, which we show next.

000010 CLASS-ID.  Walk INHERITS Form.
000020 ENVIRONMENT DIVISION.
000030 CONFIGURATION SECTION.
000040 REPOSITORY.
000050   CLASS Form AS "System.Windows.Forms.Form"
000060   -CLASS Application AS "System.Windows.Forms._Application"
000070   -CLASS Container AS "System.ComponentModel._Container"
000080   CLASS Button AS "System.Windows.Forms.Button"
000090   CLASS Timer AS "System.Windows.Forms.Timer"
000100   CLASS EventHandler AS "System.EventHandler"
000110   CLASS EventArgs AS "System.EventArgs"
000120   CLASS Point AS "System.Drawing.Point"
000130   CLASS Drawing-Size AS "System.Drawing.Size"
000140   CLASS Sys-Object AS "System.Object"
000150   -CLASS MessageBox AS "System.Windows.Forms._MessageBox"
000160   -CLASS Control-Collection AS "System.Windows. Forms.Control+ControlCollection"
000170   PROPERTY Interval AS "Interval"
000180   PROPERTY Enabled AS "Enabled"
000190   PROPERTY Location AS "Location"
000200   PROPERTY Button-Size AS "Size"
000210   PROPERTY TabIndex AS "TabIndex"
000220   PROPERTY Button-Text AS "Text"
000230   PROPERTY App-Controls AS "Controls"
000240   PROPERTY App-Text AS "Text"
000250   PROPERTY AutoScaleBaseSize AS "AutoScalBaseSize".
000260 STATIC.
000270 PROCEDURE DIVISION.
000280 METHOD-ID. MAIN.
000290 DATA-DIVISION.
000300 WORKING-STORAGE SECTION.
000310 77 Obj OBJECT REFERENCE Walk.
000320 PROCEDURE DIVISION.
000330   INVOKE Walk "New" RETURNING Obj.
000340   INVOKE Application "Run" USING BY VALUE Obj.
000350 END METHOD MAIN.
000360 END STATIC.
000370 OBJECT.
000380 DATA DIVISION.
000390 WORKING-STORAGE SECTION.
000400 77 Components OBJECT REFERENCE Container.
000410 77 Button1 OBJECT REFERENCE Button.
000420 77 Timer1 OBJECT REFERENCE Timer.
000430 PROCEDURE DIVISION
000440 METHOD-ID.  NEW.
000450 PROCEDURE DIVISION.
000460   INVOKE Self "InitializeComponent".
000470 END METHOD NEW.
000480 METHOD-ID.  DISPOSE AS "Dispose" OVERRIDE.
000490 PROCEDURE DIVISION.
000500   INVOKE SUPER "Dispose".
000510   INVOKE Components "Dispose".
000520 END METHOD DISPOSE.
000530 -METHOD-ID. INITIALIZECOMPONENT AS _"InitializeComponent".
000540 DATA DIVISION.
000550 WORKING-STORAGE SECTION.
000560 77 TICK-EVENT OBJECT REFERENCE EventHandler.
000570 77 Click-Event OBJECT REFERENCE EventHandler.
000580 PROCEDURE DIVISION.
000590   INVOKE Container "New" RETURNING Components.
000600   -INVOKE Timer "New" USING BY VALUE Components _RETURNING Timer1.
000610   INVOKE Button "New" RETURNING Button1.
000620   MOVE 2000 TO Interval OF Timer1.
000630   MOVE B'1' TO Enabled OF Timer1.
000640   -INVOKE EventHandler "New" USING BY VALUE SELF "Timer1_Tick"
000650      RETURNING Tick-Event.
000660   -INVOKE Timer1 "add_Tick" USING BY VALUE Tick-Event.
000670   SET Location OF Button1 TO Point::"New" (96 64).
000680   -SET Button-Size OF Button1 TO Drawing-Size::"New" (88 40).
000690   MOVE 0 TO TabIndex OF Button1.
000700   SET Button-Text OF Button1 TO "Stop It".
000710   -INVOKE EventHandler "New" USING BY VALUE SELF "Button1_Click"
000720      RETURNING Click-Event.
000730   -INVOKE Button1 "add_Click" USING BY VALUE Click-Event.
000740   SET App-Text OF SELF TO "Walk".
000750   -SET AutoScaleBaseSize OF SELF TO Drawing-Size::"New" (5 13).
000760   -INVOKE App-Controls OF SELF "Add" USING BY VALUE Button1.
000770 END METHOD INITIALIZECOMPONENT.
000780 METHOD-ID.  Button1_Click.
000790 DATA DIVISION.
000800 LINKAGE SECTION.
000810 77  Sender OBJECT REFERENCE Sys-Object.
000820 77  e OBJECT REFERENCE EventArgs.
000830 PROCEDURE DIVISION USING BY VALUE Sender e.
000840   MOVE B'0' TO Enabled OF Timer1.
000850 END METHOD Button1_Click.
000860 METHOD-ID.  Timer1_Tick.
000870 DATA DIVISION.
000880 LINKAGE SECTION.
000890 77 Sender OBJECT REFERENCE Sys-Object.
000900 77 e OBJECT REFERENCE EventArgs.
000910 PROCEDURE DIVISION USING BY VALUE Sender e.
000920   INVOKE MessageBox "Show" USING BY VALUE
000930      "Walk the Dog!" "Things to do".
000940 END METHOD Timer1_Tick.
000950 END OBJECT.
000960 END CLASS Walk.

Let's build this project and run it. The results are shown Figure 1–8. Kind of reminds me of my wife telling me to go walk the dog over and over until I say stop it (push the button) and I go walk the dog. The program is using the .NET base classes to implement all the code for creating the MessageBox, displaying it on a timed interval, inserting the text, and picking up when the Stop It button is pushed. It also uses the base classes for drawing and sizing the displays. This is but a minor example of the many classes and the tremendous amount of methods and data that are available in the classes for creating applications. Another interesting aspect is the creating of shorthand descriptions for activities, which saves a lot of code writing. For example, line 00090 shows CLASS Timer AS "System.Windows.Forms.Timer", however, in the code such as line 000420 when we defined the timer object, we used Timer instead of System.Windows.Forms.Timer. If you were to look at Section 2.2 in Chapter 2, you would see some of the main .NET Framework namespaces. For example, in the listing of namespaces item 9 you would see System.Drawing. Line 000130 above shows CLASS Drawing-Size AS "System.Drawing.Size". We have thus used one of the namespace methods "Size" of System.Drawing and assigned it a shorthand definition of Drawing-Size. If you look at line 000750 SET AutoScaleBaseSize OF SELF TO Drawing-Size::"New" (5 13), we are setting up the drawing size for display. More insight will be provided in Chapter 2 on how the .NET base classes are used. These base classes almost completely encapsulate the some 1,925 Win32 APIs of Windows, and we never have to worry about that amount of complexity. However, in Chapter 8 we cover some of the more fundamental Win32 APIs to give you a feel for this complexity and to let you gain some understanding of the Windows engine underneath the .NET Framework.

Figure 1-8Figure 1–8 Execution Results of Walk the Dog Code

  • + Share This
  • 🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020