Difference between revisions of "The Basics of VB6"

Revision as of 10:50, 21 September 2007

These notes can be organized later.

Open a Form From Another Form

Open the form called frmCompanies

 frmCompanies.Show

Open it so that the parent form cannot be clicked. To suspend execution of the first form until after the second form is done with, add the keyword constant vbModal as an argument to the Show method.

 frmCompanies.Show vbModal

The Hide method of a form removes the form from the screen (makes it invisible), but the form still remains in memory.

 frmCompanies.Hide
 Me.Hide
 Hide

You can load a form in memory and not display it.

 Load frmCompanies

Unload form from memory (which also closes it)

 Unload Me

Example

 Private Sub Form_Unload(Cancel As Integer)
   If MsgBox("Are you sure you want to quit?", vbYesNo + vbQuestion, "Unload Test") = vbNo Then
     Cancel = 1
   End If
 End Sub

From Dimensions and Twip Units

The default unit is the twip, which is 1/1440 of an inch for height, width, top, and left.

There are 15 twips per pixel.

Pixels to Twip:

 W = W * Screen.TwipsPerPixelX
 H = H * Screen.TwipsPerPixelY 

Twips to Pixel:

 W = W / Screen.TwipsPerPixelX
 H = H / Screen.TwipsPerPixelY

Resizing Forms

• Width: Specifies the width of the control. The default unit is the twip, which is 1/1440 of an inch.
• Height: Specifies the height of the control. The default unit is the twip, which is 1/1440 of an inch.
• Left: Specifies the distance between the internal left edge of a control and the left edge of its containter.The default unit is the twip, which is 1/1440 of an inch.
• Top: Specifies the distance between the internal top edge of a control and the top edge of its containter.The default unit is the twip, which is 1/1440 of an inch.

• ScaleWidth: The width of the client area.
• ScaleHeight: The height of the client area.
• ScaleLeft: Coordinate horizontal of upper left client area.
• ScaleTop: Coordinate vertical of upper left client area.

• ClientWidth:
• ClientHeight:
• ClientLeft:
• ClientTop: