Difference between revisions of "Hints and Recipes for VB6"

Revision as of 16:35, 18 January 2008

Date and Time examples with formatting options

 strTimeStamp = Date & " " & Format(Time, "HH:mm:ss")
 strMsg = strMsg & "date/time of request: " & Date & " " & Time & vbCrLf
 strSQLdate = Format(Date, "M/d/yyyy")

Combobox

 With cboDelimiter
   .AddItem "TAB"
   .AddItem "PIPE"
   .AddItem "SPACE"
   .AddItem "fancy!"
 End With
 cboDelimiter = "TAB"

Write/Create a new file using FileSystemObject

• must add 'reference' to "Microsoft Scripting Runtime"

 Dim fso As New FileSystemObject, fsoStream As TextStream
 Dim rec1, strLine, strFileSpec
 Dim cnt0 As Integer, tag1 As Integer
 strFileSpec = Environ("HOMEPATH") & "\My Documents\kaching.log"
 strLine = "kaching incident " & Date & " " & Format(time, "HH:mm:ss") & vbCrLf
 Set fsoStream = fso.CreateTextFile(strFileSpec, True)
 fsoStream.Write strLine
 fsoStream.Close
 Set fsoStream = Nothing: Set fso = Nothing

Write if exists, create if doesn't exist using FileSystemObject

 If fso.FileExists(strFileSpec) Then
   Set fsoStream = fso.OpenTextFile(strFileSpec, 2)
 Else
   Set fsoStream = fso.CreateTextFile(strFileSpec, True)
 End If
 
 fsoStream.Write strLine
 fsoStream.Close
 Set fsoStream = Nothing: Set fso = Nothing

 ' strFileSpec, 1 : ForReading 2 : ForWriting  8 : ForAppending  

Write to control on another form and display

 Dim lblCaught As Label
 Set lblCaught = frmKaching.lblCaught
 frmKaching.WindowState = vbNormal
 lblCaught = "You've Been Naughty!"
 frmKaching.Show

Delay without using a Timer control

 Public Sub LongDelay(intSeconds As Long)
   Dim cnt As Double
   cnt = Timer + intSeconds
   Do While Timer < cnt
     DoEvents
   Loop
 End Sub

Determine is a form has been loaded

The wrong way:

 if form1.visible = true then

The reason:

Due to the way the intrinsic variable instance works in VB, the line above will actually cause form1 to load. Forms are loaded automatically whenever referenced in code, whether loaded visibly or not.

Special thanks to a gentleman named Steve Gerrard who posted a correct sample script on another forum. His example works by going through a list of loaded forms and matching by the form name you are looking for.

 Public Function FormIsLoaded(FormName As String) As Boolean
   Dim oFrm As Form
   For Each oFrm In Forms
     If oFrm.Name = FormName Then
       FormIsLoaded = True
       Exit For
     End If
   Next oFrm
 End Function

lovely!