Just recently, I needed to implement a pause or delay loop in a Visual Basic 6 program.

Being lazy, my first instinct was just to do a for-next loop with a DoEvents in the middle. But this gave different results on different machines, which wasn’t what I was looking for.

The I tried using the Sleep API call.

But more often than not, it seemed to put the whole machine to sleep, not just my program. Plus in development, it ignored me pressing Break most of the time.

Next up, a friend suggested using the timer control. Which would probably work but has a maximum delay time and I had more hassle than I’d like trying to get it to work as intended.

A web search came up with lots of people asking the same question but not many actual answers. Most of these seemed to revolve around using the Sleep API call.

Finally, I did what I should have done and wrote my own short routine.

Just send a figure in seconds to the routine and it will run in a loop until that time is up. Simple, effective and it works without hogging the whole machine.

Public Sub DelayLoop(myDelay As Double)
Dim StartTime, EndTime
StartTime = Now
EndTime = DateAdd("s", myDelay, StartTime)
Do While CDbl(Now) < CDbl(EndTime)
	DoEvents
Loop
End Sub

I just hit an interesting error in VB6 today.

I was trying to calculate a distance between two points. No problem there except I didn’t want to put something on a page that said “48.723569″ miles. That would look dumb.

No problem, I thought, I’ll format the output using VB’s format command, giving the number string as “#####0.0″.

But for certain numbers, format kept giving me the answer 0.0

No problem, I’ll use Round instead.

Same error. Some calculations worked, others got rounded to zero regardless…

Debugging showed that the number was too long to display properly (pi is involved in the calculation, so in theory the number goes on forever).

Instead VB’s debug window displayed the start of the number but ended it in “E-02″

Which is was what confusing Format and Round.

My working (but probably not elegant) solution was to cstr the number, remove the E-02 part and then carry on:

SortedDistance = CStr(myDistance)
SortedDistance = Replace(SortedDistance, “E-02″, “”)

Two simple lines that got rid of the headache.