Thread.Pause
From Xojo Documentation
Method
Puts the thread in a paused state. Every call to Pause must be matched by a call to Resume.
Notes
The thread will not be allocated any processing cycles, regardless of its assigned Priority. It is “asleep.” To wake it up, call the Resume method. If the thread is executing when you call Pause, it will immediately cause a context switch.
Example
This example calls Pause, followed by a call to Resume after other code has executed.
LongProcessThread1.Pause
// do something else here...
LongProcessThread1.Resume
// do something else here...
LongProcessThread1.Resume