Visual Basic Introduction IDS 306 from Shelly, Cashman & Repede Microsoft Visual Basic 5: Complete Concepts and Techniques Processing • Parallel Processing more than one CPU (each with its own memory); able to carry out more than one instruction at a time • Multitasking one processor, moves back and forth between programs Graphical User Interface (GUI) Design • Should be under user’s control user should be able to customize • Form should follow function • Use concepts and metaphors familiar to user; parallel real-world experience • Visually and functionally consistent • Immediate feedback • Attempt to prevent user mistakes Program Development Life Cycle (PDLC) Methodology organized plan that breaks process into steps • Analyze the problem • Design the problem • Code the program • Test and debug program • Formalize solution • Maintain the program Hierarchical Input Process Output (HIPO) Chart • A.k.a. hierarchy chart or top-down chart • Represents subdivision of activities visually • Lowest level instruction procedure p. I.7 p. I.7 Flow Chart • Process Symbol • Input/Output (I/O) • Flowline • Annotation • Decision • Terminal • Connector • Predefined Process p. I.7 p. I.7 Major Constructs of Structured Programming • Control Structures – Sequence – Selection • Case – Repetition • Do…While • Do…Until Control Structures • Sequence Control Structure used to show a single action or one action followed in order (sequentially by another) • Selection Control Structure used to tell the program which action to take based on a certain condition • Case Control Structure form of selection that allows for more than two alternatives Control Structures (cont.) • Repetition Control Structure a.k.a. looping or iteration; used when a set of actions is performed repeatedly – Do While loop repeats as long as condition is true (may never execute) – Do Until loop evaluates condition at end of the loop (will always execute at least once) • Nested Control Structure contained within other control structures Object-Oriented Programming (OOP) • Object anything real or abstract, about which you store both data and operations that manipulate the data • Class an implementation that can be used to create multiple objects with the same attributes and behavior • Object is and Instance of a Class [...]... is a black box • Faster Design can be created from existing components Prototyping • Process where developers iterate between refining the specifications and building working models of the system Visual Basic • Properties attributes of objects • Controls check boxes, list boxes, etc • Forms windows that contain application’s controls • Events messages or requests for service • Procedures . Visual Basic Introduction IDS 306 from Shelly, Cashman & Repede Microsoft Visual Basic 5: Complete Concepts and Techniques Processing • Parallel. follow function • Use concepts and metaphors familiar to user; parallel real-world experience • Visually and functionally consistent • Immediate feedback • Attempt to prevent user mistakes Program. (HIPO) Chart • A.k.a. hierarchy chart or top-down chart • Represents subdivision of activities visually • Lowest level instruction procedure p. I.7 p. I.7 Flow Chart • Process Symbol • Input/Output