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Learn how to add menus, dialogs, and controls to your application, as well as how to use procedures, functions, and arrays in Visual Basic .NET.
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Chapter 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
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
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
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 StrictOn 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
Declaring a Two-Dimensional Array • Enter lines 331 through 339 as shown below _
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 • Enter line 342 as shown below, and press ENTER • Enter lines 343 through 366 as shown below
Coding an Array Method and Enhanced MessageBox • Enter lines 367 through 385 as shown below
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