Visual Basic 4 in 12 Easy Lessons vel4p03.htm













Visual Basic 4 in 12 Easy Lessons vel4p03.htm
























The Program's Description



The Program's Action



Close the Application









Project 3









Getting Down to Business



In this lesson, you learned about all the properties and events that are possible with the form, label, text box, and command button objects. Visual Basic can handle virtually all the requirements that your application will need.



In this lesson, you saw the following:





How to set and move the focus from object to object





What property values exist for the application's objects





Which events Visual Basic makes possible for the objects





Why you sometimes must manage labels and text boxes by using the resizing and scroll bar properties







The project named PROJECT3.VBP contains this lesson's project. You should load PROJECT3.VBP and run the application so that you can follow along with the description of this project.











The Program's Description



Figure P3.1 shows how the PROJECT3.VBP application looks as soon as you run the program. The project contains the following objects:



Figure P3.1. The project's opening screen.







Three labels







A text box control that contains a vertical scroll bar







Two command buttons, each with its own shortcut key





Notice that the top label contains a shortcut key, Alt+T, that will send the focus to the text box.



The purpose of this program is to request a message that you can enter in the text box. You can type a long or short message. After you type the message, click the center command button or press Alt+S to send that text box message to the empty label below the center command button.



The label receiving the text box data resizes automatically to adjust to the size of the text. Therefore, if you type only a single word, the label shrinks to fit around that one word. If, instead, you type several lines of text, such as a poem, all of the lines of text appear in the label because the label grows to hold all the text.











The Program's Action



Now type the words Visual Basic in the text box. Press Alt+S to send the contents of the text box to the label at the bottom of the screen. The label shrinks to hold the two words, as shown in Figure P3.2.



Figure P3.2. Watch how the label resizes.



Obviously, the command button triggers an event that takes all the text in the text box and sends a copy of it to the label at the bottom of the screen. You have yet to learn Visual Basic coding commands, so I'll save the discussion of event procedure code for the next unit.



The resizing label at the bottom of the screen contains the following Property window settings:







AutoSize: True







WordWrap: True





If the AutoSize property is not set to True, the label does not automatically shrink to fit the small text box value assigned to the label. Likewise, when you enter a larger message in the text box and press Alt+S to send it to the lower label, the label does not grow to accommodate the larger message. The WordWrap value of True ensures that the label grows vertically instead of expanding horizontally as a long, one-line label.



Try a different message. Press Alt+T to send the focus back to the text box. Press the Backspace key to erase the two words currently in the text box. Enter the following beautiful poem written several hundred years ago by a composer of lovely symphonies. (Okay, so I wrote the poem, but it is beautiful if you ask me.)







Visual Basic is like music,

ringing in my ears.

When I think of the things it does,

my eyes fill up with tears.





Press Alt+S to send the poem to the label. See how fast the label expands vertically to hold the full message. Figure P3.3 shows what your screen should look like.



Figure P3.3. The label grows as large as necessary.











Note: If you pressed Enter at the end of each poem line, your screen will match the one shown in Figure P3.3. Otherwise, your poem will be squeezed together a bit more than how it appears in Figure P3.3.















Warning: Visual Basic is extremely sensitive. If you cringe when you read the author's poetry, Visual Basic will refuse to work for you ever again.















Close the Application



Until this lesson, you would not have been able to place a label that resized automatically at runtime to fit whatever text it received. Look again at the screen. You will see another trick taught by this lesson: You can send the focus to the text box by pressing the shortcut key (Alt+T) for the label just above the text box. The only way to send the focus to the text box is to ensure that the TabIndex property for the label is one less than the TabIndex property for the text box. When Visual Basic realizes that the shortcut key sends the focus to a label that cannot receive the focus, Visual Basic sends the focus to the next control as determined by the order of the objects' TabIndex values.



You can now exit the application and exit Visual Basic. Take a rest because you will begin writing your first Visual Basic textual code in the next unit.