VISUAL BASIC

VISUAL BASIC

1. Event-driven programming language

2. Event-driven programming language

3. Form

   • The forms are treated as controls with their properties, events and methods.
     • Properties
       • Name: Name of the form, necessary to call the form from the code.
       • Backcolor: Background color of the form.
       • Forecolor: color of the form text.
       • Caption: Text that appears in the form title

4. Tool box

   • The Toolbox window shows the controls that you can add to Visual Studio projects
     • Context menu commands
       • Change item name: change the name of the selected item.
       • List view: shows the controls in a vertical list. If left unchecked, the controls appear horizontally.
       • Choose items: opens the Choose items in toolbox dialog box so you can specify the items that appear in the Toolbox. To show or hide an item, check or uncheck its box. Sort elements alphabetically: sort items by name.
       • Show all: shows all possible controls (not only those corresponding to the current designer)
       • Reset Toolbar: Restores the settings and default items in the Toolbox.
       • Add tab: add a new tab of the Toolbox.
       • Upload: moves the selected item up.
       • Download: moves the selected item down.

5. Controls

   • In Visual Basic there are three general categories of controls: Intrinsic controls, ActiveX controls, Insertable objects
     • Intrinsic controls:These controls are located within the Visual Basic executable file. Intrinsic controls are always included in the toolbox, not like Activex controls, which can be removed or added to the toolbox. Below is a list of intrinsic controls.
     • ActiveX controls: Are those controls that exist as independent files with extension file name .ocx. These include the controls available in all editions of Visual Basic (grid controls, combo box and list linked to data and several others) and those that are only available in the Professional Edition and Enterprise Edition (such as Listview, Toolbar, Animation and Tabbed Dialog). To these are also added ActiveX controls from other manufacturers.
     • Insertable objects:As a Microsoft Excel Worksheet object that contains the list of your company's employees, or a Microsoft Project Calendar object that contains the calendar information of a project. Since these objects can be added to the toolbox, they are considered controls.

6. Properties

   • DateString: Returns or sets a String value representing the current date according to your system.
   • Now: Returns a Date value containing the current date and time according to your system.
   • ScriptEngine: Returns a String representing the runtime currently in use.
   • ScriptEngineBuildVersion: Returns an Integer containing the build version number of the runtime currently in use.
   • ScriptEngineMajorVersion: Returns an Integer containing the major version number of the runtime currently in use.
   • ScriptEngineMinorVersion:Returns an Integer containing the minor version number of the runtime currently in use.
   • TimeOfDay:Returns or sets a Date value containing the current time of day according to your system.
   • Timer:Returns a Double value representing the number of seconds elapsed since midnight.
   • TimeString :Returns or sets a String value representing the current time of day according to your system.
   • Today:Returns or sets a Date value containing the current date according to your system.

7. Control structures

   • Decision
     • CASE
       • The Select Case structure allows us to avoid the use of several If. This structure extends the functionality of the IF structure, avoiding the writing of nested If.
     • IF
       • The IF structure is used to perform different statements based on a condition. The conditions must be elements to evaluate whose result can be True or False. For the conditions the symbols of comparison
   • Cycles
     • FOR NEXT
       • allows you to control the number of times the instructions are executed within the loop. This structure consists of a start value, a final value and an increment value. A cycle variable is indicated that will take from the initial value to the final value with a predetermined increment of 1.
     • WHILE-WHEND
       • In these cycles, (also called loops) "While - Wend", the number of times the sentences are repeated within the cycle depends exclusively on whether the condition of that cycle is verified as valid.

8. Type of data

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