visual basic.net comprehensive concepts and techniques chapter 7 using menus, common dialogs,...

Visual Basic .NETComprehensive Concepts

and Techniques

Chapter 7

Using Menus, Common Dialogs, Procedures, Functions, and Arrays

2Chapter 7: Using Menus, Common Dialogs, Procedures, Functions, and Arrays

Objectives

• Add a menu bar and menus to an application using the MainMenu control

• Add a shortcut menu to an application using the ContextMenu control

• Use the StatusBar control in an application• Use the PictureBox control in an

application• Use common dialog boxes in an

application to interact with the user


Objectives

• Use one-dimensional and multidimensional arrays in code

• Write a function procedure to return a value

• Write a sub procedure

• Write code to pass arguments to function and sub procedures


Objectives

• Describe the two methods for passing arguments to functions and procedures

• Create an enhanced message box with the MessageBox.Show() method

• Use a collection of controls to access properties and methods in code


Creating the User Interface

• Open a New Project named Know Your Dogs Quiz in the Chapter7 folder on your Data Disk

• Set the following properties for your form


Adding Controls

• Add a StatusBar control by dragging the StatusBar button from the Toolbox window to the bottom of the Form1 form

• Add one PictureBox, one GroupBox, four RadioButtons inside the GroupBox, and two Buttons

• Add a ContextMenu control• Add a FontDialog control• Set the control properties as they appear in table

7-4 on pages VB 7.19 – VB 7.21


Creating Menus on a Menu Bar

• Click the MainMenu1 control in the Component Tray

• Click the Type Here indicator in the Menu Designer. Type &File as the Text property value to create the File menu on the menu bar, and press the ENTER key

• Set the Name property for the File menu item as indicated in Table 7-6 on page VB 7.24

• Click the Type Here indicator below the File menu item in the Menu Designer. Type E&xit as the Text property value


Creating Menus on a Menu Bar

• Create the remaining menus and menu items as shown in Table 7-6 on page VB 7.24

• To add a Separator Bar, right-click the area in the Menu Designer you want the Separator Bar to appear, and select Insert Separator from the shortcut menu

• Adding an ampersand (&) before a letter in the Text property of a menu designates that letter as a keyboard shortcut key

• Rename the MainMenu control to mnuMain


Creating a Shortcut Menu for a Form• Click the ContextMenu1 control in the Component

Tray• Click the Context Menu indicator. When the Type

Here indicator appears, add the menu items appearing in Table 7-7 on page VB 7.30

• To insert a Separator Bar, type a dash (-) for the menu item

• Select the ContextMenu1 control in the Component Tray and set the control’s Name property value to cmuShortcut

• Select the Form1 form. Set the ContextMenu property in the Properties window to cmuShortcut


The StatusBar


Changing the Properties of a StatusBar Control• Click the StatusBar1 control on the Form1

form. Change the Name property to stbQuestion. Select the Panels property in the Properties window and then click the Panels property ellipsis button

• Click the Add button. When the StatusBarPanel1 panel is added, select the AutoSize property and then click the AutoSize box arrow


Changing the Properties of a StatusBar Control• Click the Spring property

value and then click the OK button. When the StatusBarPanel Collection Editor window closes, select the ShowPanels property in the Properties window and change the ShowPanels property to True


The PictureBox

• Commonly used properties of the PictureBox control


Changing the Properties of a PictureBox Control• Click the PictureBox1 control and set the

properties in the properties window to those specified below


Common Dialog Controls

• Windows applications often share requirements for certain types of input

• Applications use similar dialog boxes to open, print, preview, or save a file

• ShowDialog() method


FontDialog Control Properties


Changing the Properties of a FontDialog Control• Click the FontDialog1 control and change

the property values listed below


Arrays

• Allows programmers to represent many values with one variable name

• Elements in the array are distinguished by their subscript


The Dim Statement for Arrays


Dynamic Dimensioning of Arrays

• Has a variable or expression for its upper-bound value

• Visual Basic .NET permits the size of an array in a Dim statement to be written as a simple variable

• Dim intCode(gintSize) As Integer


Declaring Arrays

• Right-Click the Form1 form in the Solution Explorer. Click the View Code command

• Enter Option Strict On as the first line of code in the code window

• Enter the code below, starting on line 320


Indexes

• Elements in an array are referenced in code by their index


Function Procedures

• Performs tasks and returns a value back to the code that called it

• Similar to VB.NET’s intrinsic functions

• Function statements declare function procedures– Private Function

InventoryCounts() As Integer()

• Common Statements in Functions– Return statement– Exit Function statement– End Function statement


Declaring a Function Procedure and Using Arrays in Code• Enter the code below, starting on line 333


Coding the Menu Command and Using the FontDialog Control in Code

• Click the Form1.vb tab in the main work area. Double-click the Exit command on the File menu of the Form1 form

• Type line 345 (shown on the next slide) in the code window

• Click the Design tab in the main work area, double-click the Font command on the Options menu, and type lines 349 through 355 shown on the next slide


Multidimensional Arrays


Declaring a Two-Dimensional Array

• Enter lines 331 through 339 as shown below

_


Array Methods


Declaring Sub Procedures


Passing Arguments Between Procedures• Passing By Value method

– ByVal keyword– Passes the value of the variable (default method)– CalculateTax((dblIncome), intTaxBracket)

• Passing By Reference method– ByRef keyword– Passes the reference location of the variable– Allows you to modify the variable– Private Sub CalculateTax(ByRef dblValue As Double)


Coding a Sub Procedure


Coding a Sub Procedure

• Enter line 342 as shown below, and press ENTER• Enter lines 343 through 366 as shown below


Enhanced MessageBox Features


Using an Array and an Enhanced Message Box


Coding an Array Method and Enhanced MessageBox• Enter lines 367 through 385 as shown

below


Using a Control Collection


Using a Control Collection

• Enter lines 386 through 403 as shown below


Calling a Sub Procedure

• Code the five event procedures as shown on the following slide– Form1_Load– mnuFirst_Click– mnuLast_Click– mnuNext_Click– mnuPrevious_Click


Using the PerformClick() Method

• Used when you want to execute the Click event procedure for a control

• Ensures visual effects are handled, in addition to calling the Click event procedure

• Best used when several event procedures perform duplicate actions

• Enter the code on the following slide for the seven event procedures shown


Finish the Project

• Click the Save All button on the Standard toolbar

• Test your project by taking the Know Your Dogs quiz. Test the MainMenu and the ContextMenu

• Print your program’s documentation

• Quit Visual Basic .NET


Summary

• Add a menu bar and menus to an application using the MainMenu control

• Add a shortcut menu to an application using the ContextMenu control

• Use the StatusBar control in an application• Use the PictureBox control in an

application• Use common dialog boxes in an

application to interact with the user


Summary

• Use one-dimensional and multidimensional arrays in code

• Write a function procedure to return a value

• Write a sub procedure

• Write code to pass arguments to function and sub procedures


Summary

• Describe the two methods for passing arguments to functions and procedures

• Create an enhanced message box with the MessageBox.Show() method

• Use a collection of controls to access properties and methods in code

Visual Basic .NETComprehensive Concepts

and Techniques

Chapter 7 Complete

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