OnMessage() Cause temporary variables to empty Topic is solved

[feiyue]

When I used OnMessage ()+SetTimer, I found that the variables of the subroutine inside the function were confusing.
Look at the following example. Why is the value of variable “i” empty?

Code: Select all

Gui, Show, w500 h300
OnMessage(0x200, "WM_MOUSEMOVE")
return

WM_MOUSEMOVE() {
  SetTimer, Test, -100
  return

  Test:
  i=1
  Loop 10 {
    Sleep, 100
    j=1
  } Until (i!=j)
  MsgBox, %i% - %j%
  return
}

[kczx3]

Labels inside functions is just a bad idea anyways...

[Helgef]

When a function returns, its non-static variables are made blank.

subroutines should use only static and global variables (not locals) if their function is ever called normally. This is because a subroutine thread that interrupts a function-call thread (or vice versa) would be able to change the values of local variables seen by the interrupted thread. Furthermore, any time a function returns to its caller, all of its local variables are made blank to free their memory.

[User]

Yha, it seems that "labels" inside functions are not recommended in some situations!

You can use the below alternative:

Code: Select all

Gui, Show, w500 h300
OnMessage(0x200, Func("WM_MOUSEMOVE").Bind("OnMessage_Call"))
return

guiclose:	;________________
exitapp


WM_MOUSEMOVE(Options := "") {	;_______________________________

	if (Options = "OnMessage_Call")
	{
		;msgbox, OnMessage_Call Test

	SetTimer, % A_ThisFunc, -100

	return
	}

  i=1
  Loop 10 {
    Sleep, 100
    j=1
  } Until (i!=j)
  MsgBox, %i% - %j%

}

[just me]

When a function returns, its non-static variables are made blank.

So

1. Code: Select all

   WM_MOUSEMOVE() {
      Static c, i, j
      SetTimer, Test, -100
      Return
   
      Test:
      i := 1
      Loop 10 {
         Sleep, 100
         c := A_Index
         j := 1
      } Until (i != j)
      MsgBox, %i% - %j% - %c%
      Return

2. It isn't a bug!

[feiyue]

Yes, I didn't realize before that subroutines in functions would be affected by this.