meljun cortes visual basic control arrays
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CONTROL ARRAYS
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Overview
Definition of Control Arrays
Characteristics of Control Arrays
Uses of Control Arrays
How to create Control Arrays
Example / Demonstration
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is a group of controls of the same typethat have thesame nameand share the same set of event procedureor provide similar functionality.
Definition of Control Arrays
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Characteristics of Control Arrays
each control array element maintains its ownproperties
share its event procedure code with the other controlarray elements
have minimum lower boundof 0 and a maximum upperbound32767
control array bounds are not affected by Option Base(unless the programmer specifies otherwise, 0 isalways the lower bound
each control array element is uniquely identified by itsInteger Index property
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Uses of Control Arrays
to group together existing controls
fewer resources than simply adding multiple controls ofthe same type to a form at design time.
useful if you want several controls to share code
Example: if three option buttons are created as a controlarray, the same code is executed regardless of whichbutton was clicked
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How to create Control Arrays?
By giving a control the same name as another control
By copying a forms control and pasting the copy onthe form
Explicitly setting a controls Indexproperty
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Control Array Dialog Box
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Example
A government lab wants to install a security keypad outside a laboratory
room. Only authorized personnel may enter the lab, using their securitycodes. The following are valid security codes:
16451689 = Technician Personnel
8345 = Custodial Services
55875 = Special Services
999898, 10000061000008 = Scientific Personnel
As an added security measure, the keypad treats any access less than1000 as a panic code by sounding a single beep. Although access is
denied, security is notified immediately. Once an access code isentered, access is either granted or denied. All access attempts arewritten to a window below the keypad. If access is granted, the date,time, and group (i.e., Technician Personnel, Custodial Services, etc.)are written to the window. If access is denied, the date, time and themessage Access Denied are written to the window.
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Example: Explained
True
True
True
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Example: Sample GUI
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Example: Explained (Case Multiple Selection Structure)
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Example: Explained (Control Arrays)
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Review
Definition of Control Arrays
Characteristics of Control Arrays
Uses of Control Arrays
How to create Control Arrays