VB6.0 – 04 - Advanced Objects
An introductory course.
Presented by Charley Jones, Manpower Professional,
Course WebPage: www.crjones.com/vb
Review:
So far we’ve covered:
Objects Nouns Car, Form, Button
Properties Adjectives Car.Color, Form.Left, Button.Caption
Methods Actions Car.Drive, Form.Move, Button.Hide
Events Trigger Form_Load(), Button_Clicked()
Application Holds data on our project. App.Title, App.Version
Forms Basic display unit in VB. Form.Caption
CommandButton Allows action on form. Button.Caption
TextBox Accepts / displays input. Text1.Text
Labels Label1.Caption
Listboxes List1.AddItem(), List1.Clear(), List1.ListCount,
List1.List(X), List1.Selected(X), List1.Style
ComboBoxes Combo1.Text
CheckBoxes Checkbox1.Value = 1/0
RadioButtons Option1.Value = True/False
Frames Frame1.Caption
Scrollbars Hscroll1.Value
Timers Timer1.Interval, Timer1_Tick()
Modal Forms myForm.Show vbModal
Modless Froms myForm.Show / myForm.Show vbModeless
The class challenges last time were:
This week, we’re continuing our look at the basic toolbar:
Line Object
Used to draw a line on a form
Line.BorderWidth Width of Line
Line.BorderStyle 1=Solid, 2=Dashed, 3=Dot, 4=DashDot…
Line.X1 Line.Y1 Left Top of Line.
Line.X2 Line.Y2 Bottom Right of Line.
Shape Object
Used to draw shapes on the form.
Shape1.BorderStyle 1=Solid, 2=Dashed, 3=Dot, 4=DashDot…
Shape1.Shape 0=Rectangle, 1=Square, 2=Oval, 3=Circle…
Picture Object
Used to display (and create) images on form.
Not as fast as Image object, a little more greedy and slow.
You can draw directly in a Picture Control.
Picture1.Line (0,0) – (500,1000) Draw line for 0,0 to 500,1000
Picture1.Cicle (1000,1000), 500 Draw circle with radius 500 at 1000,1000
Picture1.Cls Clear Screen
Picture1.Picture = LoadPicture("C:\Program Files\Microsoft Visual Studio\
Common\Graphics\Bitmaps\Assorted\Beany.bmp")
Image Object
Used to display images (bitmaps, icons) on form.
Faster than Picture object, not as many options.
Image1.Picture = LoadPicture("C:\Program Files\Microsoft Visual Studio\
Common\Graphics\Bitmaps\Assorted\Beany.bmp")
Image1.Left = Image1.Left = 100
Image1.Hide
Image1.Picture = Nothing
You can also directly draw on form:
Form1.Line (0,0) – (500,1000)
Form1.Cicle (1000,1000), 500
Form1.Cls
And now for something completely different:
A mini file browser using:
DriveListBox,
Drive1.Drive Current Drive
DirectoryListBox,
Dir1.Path Current Path on Drive
FileListBox.
File1.FileName Selected Filename
File1.Path Path to list
File1.Pattern Pattern to list *.*
*.DOC;*.XLS
Making it work, the Change event.
Double click on the drive List box.
Notice that you’re in the code at: Drive1_Change
The change event fires every time there’s a change in the object.
So, when the Drive Changes, let’s change the path of the Directory List Box:
Private Sub Drive1_Change()
Dir1.Path = Drive1.Drive
End Sub
And let’s cascade that change to the FileListBox.
Whenever the directory is changed (by Drive1 or by clicking)
the Dir1_Change event fires.
Private Sub Dir1_Change()
File1.Path = Dir1.Path
End Sub
Exercises:
Now that we’ve got some new controls under our belt,
Let’s try them out in few projects:
VB6-4-1: Picture Viewer:
Write a project to view pictures on the hard drive.
Should only display JPG’s and GIF’s…
VB6-4-2: Analog Clock.
A little bit harder,
(A lot more code)
But with our new graphics abilities,
Try to write a digital clock…
VB6-04 - 1 -