#include <GuiRichEdit.au3>
#include <GuiConstantsEx.au3>
#include <WindowsConstants.au3>
$sText = ''
$iRandom = Random(50, 200, 1)
For $i = 1 To $iRandom
$sText &= Chr(Random(65, 90, 1))
Next
$hGui = GUICreate('Test', 300, 160)
$nLabel = GUICtrlCreateLabel('Длина текста в RichEdit: ' & $iRandom, 10, 10, 280, 20)
$hRichEdit = _GUICtrlRichEdit_Create($hGui, $sText, 10, 50, 280, 35, _
BitOR($WS_HSCROLL, $ES_AUTOHSCROLL))
_GUICtrlRichEdit_GotoCharPos($hRichEdit, 0)
$nButton = GUICtrlCreateButton('GO', 100, 100, 100, 30)
GUISetState()
While 1
$nMsg = GUIGetMsg()
Switch $nMsg
Case $GUI_EVENT_CLOSE
_GUICtrlRichEdit_Destroy($hRichEdit)
Exit
Case $nButton
$sText = ''
$iRandom = Random(50, 200, 1)
For $i = 1 To $iRandom
$sText &= Chr(Random(65, 90, 1))
Next
_GUICtrlRichEdit_SetSel($hRichEdit, 0, -1)
_GUICtrlRichEdit_ReplaceText($hRichEdit, $sText)
GUICtrlSetData($nLabel, 'Длина текста в RichEdit: ' & $iRandom)
_GUICtrlRichEdit_GotoCharPos($hRichEdit, 0)
EndSwitch
WEnd