Clipboard - New content notifications?

Targets Windows
1

Is there a (recommended?) way to know when the clipboard content changes?

Any help/suggestions will be appreciated.

Ken.

2

To be notified you’ll need to be able to receive raw window messages from the system and then register to receive clipboard notification messages. This is doable in Xojo but not simple; see the HotKeyHelper class in the Windows Functionality Suite for an example of receiving window messages.

A much simpler solution is to poll the clipboard sequence number:

Function HasClipboardChanged() As Boolean
  Declare Function GetClipboardSequenceNumber Lib "User32" () As Integer
  Static lastSeqNum As Integer
  Dim current As Integer = GetClipboardSequenceNumber()
  If current <> lastSeqNum Then
    lastSeqNum = current
    Return True
  End If
End Function
3

Thanks Andrew.

So would I put that code onto a timer to constantly monitor the clipboard?

4

Yes. I’d suggest using the shortest possible period (1ms) for the Timer.

5

Many thanks. :wink:

6

You cant use a period shorter than 16ms in windows with regular timers.

The propper way is with declares: sensing when the clip board has changed - #10 by David_Cox

But the timer can work Ok

7

The intent of using a 1ms period here is to have the timer run on every iteration of the event loop, however frequently that may be.

1 Like
8

Then you can use “timer timeout of 0 that means the next event loop” you can use timer.Calllater 0, AddressOf AMethod