Trouble with Yield()?

Hi all,

I'm trying to add a STOP button on the screen for a merge process so the user can stop the loop if the number of certificates on the selected salesorder is high. I added a yield() statement to the loop and a check for the value of the instance variable ib_stop, but it loops through so fast that often times the STOP click is missed. Sometimes if I double-click the STOP button, it works, but not always. Here's the code:

//wf_merge_each
integer li_CertCount, li_ThisCert, li_x, li_rc

//Loop through all of the Certs in the ddlb
ib_stop = FALSE
cb_stop.visible = TRUE
li_CertCount = ddlb_certs.TotalItems()
for li_x = 1 to li_CertCount
	st_6.Text = "Merging " + string(li_x) + " of " +  string(li_CertCount) + " ... Please wait..."
	ddlb_certs.SelectItem(li_x)
	ddlb_certs.Event SelectionChanged(li_x)
	li_rc = wf_merge_one()
	if li_rc = -1 then
		return
	end if
	Yield()
	if ib_stop = TRUE then
		exit
	end if
next
if ib_stop = TRUE then
	st_6.Text = "Merged " + string(li_x) + " of " +  string(li_CertCount) + " ... Merge cancelled..."
else
	st_6.text = "Merge complete: " + string(li_CertCount) +" documents."
end if

cb_stop.visible = 	FALSE
return

Any thoughts? I tried adding 4 more Yields() but that doesn't fix the problem.

TIA,
Tracy

Comment

Tracy Lamb
Tuesday, 16 July 2024 20:52 PM UTC

This is a definite improvement, but sometimes I still have to click the STOP button twice. So I just changed the text on the button to "Click twice to Stop", lol. I'm using a 500ms sleep. 250ms was too fast, and I had to click STOP 3 or 4 times. I also added a Yield() statement before each dw retrieve in the ddlb.selectionchanged event. The selectionchanged event retrieves data into 3 different dws. My data is on a remote server, so I'll be curious to see how well this works for my customer when he's connected locally to his server.

Thanks Miguel!

~~~Tracy

Helpful 0

There are no comments made yet.

Tracy Lamb
Tuesday, 16 July 2024 12:47 PM UTC

Would Sleep() work? Help says it suspends the application... I just want the loop to pause long enough to allow the user to click the STOP button.

Miguel Leeuwe
Tuesday, 16 July 2024 13:01 PM UTC

Powerbuilder's Sleep function should work, but can only be specified in full seconds. I'm looking at some code that I have to use the WinApi Sleep which can be specified in milliseconds.

I'll try to make a simple test app. Give me some time please.

regards

Miguel Leeuwe
Tuesday, 16 July 2024 13:15 PM UTC

This is the External function declaration:

Subroutine Sleep_ms( ULONG ulMilliseconds ) Library "Kernel32.dll" alias for "Sleep"

After your Yield(), call Sleep_ms(1)

1 millisecond was enough for my test case (which I'll now attach in another answer).

Resolved Trouble with Yield()?