LV_SortArrow.ahk

; LV_SortArrow by Solar. http://www.autohotkey.com/forum/viewtopic.php?t=69642
; h = ListView handle
; c = 1 based index of the column
; d = Optional direction to set the arrow. "asc" or "up". "desc" or "down".
LV_SortArrow(h, c, d="") {
	static ptr, ptrSize, lvColumn, LVM_GETCOLUMN, LVM_SETCOLUMN
	if (!ptr)
		ptr := A_PtrSize ? ("ptr", ptrSize := A_PtrSize) : ("uint", ptrSize := 4)
		,LVM_GETCOLUMN := A_IsUnicode ? (4191, LVM_SETCOLUMN := 4192) : (4121, LVM_SETCOLUMN := 4122)
		,VarSetCapacity(lvColumn, ptrSize + 4), NumPut(1, lvColumn, "uint")
	c -= 1, DllCall("SendMessage", ptr, h, "uint", LVM_GETCOLUMN, "uint", c, ptr, &lvColumn)
	if ((fmt := NumGet(lvColumn, 4, "int")) & 1024) {
		if (d && d = "asc" || d = "up")
			return
		NumPut(fmt & ~1024 | 512, lvColumn, 4, "int")
	} else if (fmt & 512) {
		if (d && d = "desc" || d = "down")
			return
		NumPut(fmt & ~512 | 1024, lvColumn, 4, "int")
	} else {
		Loop % DllCall("SendMessage", ptr, DllCall("SendMessage", ptr, h, "uint", 4127), "uint", 4608)
			if ((i := A_Index - 1) != c)
				DllCall("SendMessage", ptr, h, "uint", LVM_GETCOLUMN, "uint", i, ptr, &lvColumn)
				,NumPut(NumGet(lvColumn, 4, "int") & ~1536, lvColumn, 4, "int")
				,DllCall("SendMessage", ptr, h, "uint", LVM_SETCOLUMN, "uint", i, ptr, &lvColumn)
		NumPut(fmt | (d && d = "desc" || d = "down" ? 512 : 1024), lvColumn, 4, "int")
	}
	return DllCall("SendMessage", ptr, h, "uint", LVM_SETCOLUMN, "uint", c, ptr, &lvColumn)
}