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CHAPTER THREE

CHAPTER THREE. Program Design and Coding. Objectives. Change the BackColor property of an object Add images to a PictureBox object Locate and save an image from the World Wide Web Import an image into the Program Resources folder Size an image. Objectives.

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CHAPTER THREE

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  1. CHAPTER THREE Program Design and Coding

  2. Objectives • Change the BackColor property of an object • Add images to a PictureBox object • Locate and save an image from the World Wide Web • Import an image into the Program Resources folder • Size an image Chapter 3: Program Design and Coding

  3. Objectives • Set the Visible property in the Properties window • Set the Enabled property in the Properties window • Run a Visual Basic 2010 program • Enter Visual Basic 2010 code • Understand Visual Basic 2010 code statement formats Chapter 3: Program Design and Coding

  4. Objectives • Use IntelliSense to enter Visual Basic 2010 code statements • Using code, set the Visible property of an object • Using code, set the Enabled property of an object • Enter comments in Visual Basic 2010 code Chapter 3: Program Design and Coding

  5. Objectives • Correct errors in Visual Basic 2010 code • Write code to use the Close() procedure • Print code • Prepare an Event Planning Document Chapter 3: Program Design and Coding

  6. Preview the Chapter Project Chapter 3: Program Design and Coding

  7. BackColor Property • Click the Windows Form object to select it • If necessary, scroll in the Properties window until the BackColor property is displayed, and then click the right column of the BackColor property • Click the BackColor arrow. Then, if necessary, click the Web tab to display the Web tabbed page • Scroll to display the color you wish to apply • Click the color you wish to apply on the color list Chapter 3: Program Design and Coding

  8. BackColor Property Chapter 3: Program Design and Coding

  9. BackColor Property Chapter 3: Program Design and Coding

  10. Locating and Saving an Image from the World Wide Web • Open your Internet browser. Then, enter scsite.com/vb2010/ch3/imagesin the Address box and press the ENTER key • Locate the StandardRoom.jpg image and then right-click the image • Click Save Picture As on the shortcut menu • Identify the drive and folder where the image will be stored. Enter the image file name, StandardRoom, in the File name text box • Click the Save button in the Save Picture dialog box to save the image in the selected location Chapter 3: Program Design and Coding

  11. Locating and Saving an Image from the World Wide Web Chapter 3: Program Design and Coding

  12. Locating and Saving an Image from the World Wide Web Chapter 3: Program Design and Coding

  13. Importing the Image into the Program Resources Folder • With Visual Studio 2010 and the Hotel Room Selection Visual Basic program open, select the picStandardRoomPictureBox object by clicking it. Scroll in the PictureBox Properties window until the Image property is visible. Click the Image property name in the left list in the Properties window • Click the Ellipsis button in the right column of the Image property • Click the Import button in the Select Resource dialog box. Then, using the features of the Open dialog box, locate the file you want to import into the program Chapter 3: Program Design and Coding

  14. Importing the Image into the Program Resources Folder • Click the Open button in the Open dialog box • With the StandardRoom file name selected in the Project resource file list, click the OK button in the Select Resource dialog box Chapter 3: Program Design and Coding

  15. Importing the Image into the Program Resources Folder Chapter 3: Program Design and Coding

  16. Sizing an Image • With the PictureBox object containing the StandardRoom image selected, scroll in the picStandardRoom Properties window until you see the SizeMode property. Click the SizeMode property name in the left column and then click the SizeMode arrow in the right column of the SizeMode property • Click StretchImage in the SizeMode list Chapter 3: Program Design and Coding

  17. Sizing an Image Chapter 3: Program Design and Coding

  18. Sizing an Image Chapter 3: Program Design and Coding

  19. Visible Property • If necessary, select the picStandardRoom PictureBox object. Scroll in the Properties window until the Visible property is displayed. Click the Visible property name in the left column, and then click the Visible arrow in the right column of the Visible property • Click False on the Visible property list Chapter 3: Program Design and Coding

  20. Visible Property Chapter 3: Program Design and Coding

  21. Visible Property Chapter 3: Program Design and Coding

  22. Enabled Property • Select the btnSelectRoom object. Scroll in the Properties window until the Enabled property is displayed. Click the Enabled property name in the left column, and then click the Enabled arrow in the right column of the Enabled property • Click False on the Enabled property list Chapter 3: Program Design and Coding

  23. Enabled Property Chapter 3: Program Design and Coding

  24. Enabled Property Chapter 3: Program Design and Coding

  25. Running a Program • Point to the Start Debugging button on the Standard toolbar • Click the Start Debugging button on the Standard toolbar Chapter 3: Program Design and Coding

  26. Running a Program Chapter 3: Program Design and Coding

  27. Entering Visual Basic Code for Event Handling • With Visual Studio 2010 and the Hotel Room Selection program open and the frmHotelRoomSelection.vb [Design] tabbed window visible, point to the Standard Room Button object in the Windows Form object • Double-click the Standard Room Button object Chapter 3: Program Design and Coding

  28. Entering Visual Basic Code for Event Handling Chapter 3: Program Design and Coding

  29. Entering Visual Basic Code for Event Handling Chapter 3: Program Design and Coding

  30. Visual Basic 2010 Coding Statements • The Visual Basic syntax specifies how each statement must be written • When the user clicks the Standard Room button while the program is running, the standard room image should be displayed in the picStandardRoom PictureBox object Chapter 3: Program Design and Coding

  31. General Format of a Visual Basic Statement Chapter 3: Program Design and Coding

  32. IntelliSense • IntelliSense displays all allowable entries you can make in a Visual Basic statement each time a dot (period), equal sign, or other special character required for the statement is typed Chapter 3: Program Design and Coding

  33. Entering a Visual Basic Statement • With the code window open and the insertion point positioned as shown in Figure 3-25 on page 131, type picfollowed by a period • To identify the correct entry, type the first letters of the entry until the entry is selected. In this case, type son your keyboard • When IntelliSense highlights the correct object name, press the key on the keyboard corresponding to the entry that is to follow the object name. In this case, press the PERIOD key • As with the object name in the second step, the next step is to enter one or more characters until IntelliSense highlights the desired property in the list. Type the letter, v on your keyboard Chapter 3: Program Design and Coding

  34. Entering a Visual Basic Statement • Press the key for the character that is to follow the property name. In this case, press the SPACEBAR on the keyboard • Press the EQUAL SIGN key on the keyboard and then press the SPACEBAR. On the IntelliSense list, click the Common tab to display the most common results • Type t on the keyboard • Press the key for the character that is to follow the True entry. In this case, press the ENTER key Chapter 3: Program Design and Coding

  35. Entering a Visual Basic Statement Chapter 3: Program Design and Coding

  36. Entering a Visual Basic Statement Chapter 3: Program Design and Coding

  37. Setting the Visible Property to False • With the insertion point on the second line of the code editing window for the Click event of the Standard Room button, type picon your keyboard • Type dto highlight the picDeluxeRoom entry in the IntelliSense list • Press the key on the keyboard for the character that is to follow the object name. In this case, press the PERIOD key • Press the SPACEBAR, press the EQUAL SIGN key, and then press the SPACEBAR • Type f and then press the ENTER key Chapter 3: Program Design and Coding

  38. Setting the Visible Property to False Chapter 3: Program Design and Coding

  39. Setting the Visible Property to False Chapter 3: Program Design and Coding

  40. Enabled Property • Type btnto display the IntelliSense list • Type seuntil IntelliSense highlights the btnSelectRoom entry in the list • Type a period, type e, press the SPACEBAR, press the EQUAL SIGN key, press the SPACEBAR again, and then type t to select True in the IntelliSense list • Press the ENTER key to enter the completed statement and place the insertion point on the next line Chapter 3: Program Design and Coding

  41. Enabled Property Chapter 3: Program Design and Coding

  42. Enabled Property Chapter 3: Program Design and Coding

  43. Comments in Program Statements • To insert a blank line following the event code generated by Visual Studio that begins with the word, Private, click anywhere in that line and then press the END key on your keyboard • Press the ENTER key • Type the first line of the comments, beginning with an apostrophe, as shown in Figure 3-46 on page 143, and then press the ENTER key Chapter 3: Program Design and Coding

  44. Comments in Program Statements Chapter 3: Program Design and Coding

  45. Comments in Program Statements Chapter 3: Program Design and Coding

  46. Same Line Comments Chapter 3: Program Design and Coding

  47. Introductory Comments • Click to the left of the word, Public, on line 1 in the program to place the insertion point on that line • Press the ENTER key one time, and then press the UP ARROW key one time • Type an apostrophe, a space, the text, Program Name: and then press the TAB key one time • Type Hotel Room Selection as the name of the program. Then, press the ENTER key Chapter 3: Program Design and Coding

  48. Introductory Comments Chapter 3: Program Design and Coding

  49. Introductory Comments Chapter 3: Program Design and Coding

  50. Correcting Errors in Code • Using IntelliSense reduces the likelihood of coding errors considerably, although it is still possible to code an error • One possible error may be forgetting an apostrophe in a comment statement • A build errors message means the Visual Basic compiler detected a coding error in the program Chapter 3: Program Design and Coding

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