The Basics of VB6: Difference between revisions

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New page: 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 s...
 
 
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These notes can be organized later.   
These notes can be organized later.   


=== Open a Form From Another Form ===
=== Select Case (Switch) ===


Open the form called frmCompanies
CASE in Visual BASIC does not "fall through" like in C.
  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 ===
  Select Case Button.Key
    Case "ListCache"
      mnuListCache_Click
    Case "Refresh"
      mnuRefresh_Click
    Case "simmode"
      cmdSimMode_Click
  End Select


The default unit is the twip, which is 1/1440 of an inch for height, width, top, and left.
  Select Case tcpClient.State
    Case 0
      tcpClient.RemoteHost = cboRemoteHost
      SessionConnect
    Case 7
      lblStatus.Caption = "Connected"
    Case 9
      lblStatus.Caption = "Connection Error"
  End Select


Pixels to Twip:
Case based on more than one condition
   W = W * Screen.TwipsPerPixelX
 
  H = H * Screen.TwipsPerPixelY
   Select Case True
Twips to Pixel:
    Case strMessage Like "*OK*" And lblStatus.Caption = "Connected"
   W = W / Screen.TwipsPerPixelX
    blnReceivedAll = True
   H = H / Screen.TwipsPerPixelY
  Case strMessage Like "*OK*" And lblStatus.Caption = "retrieving."
    lblStatus.Caption = "retrieving.."
    blnReceivedAll = True
   Case Else
    Set LoopTime = New TimerClass: tmrDisconnect.Enabled = True
   End Select
 
=== Public Declarations ===
 
Public strCurrentTool As String
 
Public fMainForm As frmQAB
 
Public cn As ADODB.Connection
 
Public rsCompanies As ADODB.Recordset
 
Public Const dbtContact = "contact"
 
 
 
 
 
 
 
 
[[Category:Computer Technology]]
[[Category:Programming]]
[[Category:VB6]]

Latest revision as of 09:55, 2 February 2008

These notes can be organized later.

Select Case (Switch)

CASE in Visual BASIC does not "fall through" like in C. 

 Select Case Button.Key
   Case "ListCache"
     mnuListCache_Click
   Case "Refresh"
     mnuRefresh_Click
   Case "simmode"
     cmdSimMode_Click
 End Select

 Select Case tcpClient.State
   Case 0
     tcpClient.RemoteHost = cboRemoteHost
     SessionConnect
   Case 7
     lblStatus.Caption = "Connected"
   Case 9
     lblStatus.Caption = "Connection Error"
 End Select

Case based on more than one condition 

 Select Case True
   Case strMessage Like "*OK*" And lblStatus.Caption = "Connected"
   blnReceivedAll = True
 Case strMessage Like "*OK*" And lblStatus.Caption = "retrieving."
   lblStatus.Caption = "retrieving.."
   blnReceivedAll = True
 Case Else
   Set LoopTime = New TimerClass: tmrDisconnect.Enabled = True
 End Select

Public Declarations

Public strCurrentTool As String

Public fMainForm As frmQAB

Public cn As ADODB.Connection

Public rsCompanies As ADODB.Recordset

Public Const dbtContact = "contact"


 

 

 

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