Wiedereinmal ein Skript, das es schon einige Male gibt, aber ich will immer alles auf meine Art machen 
Zuerst Bereich markieren, F9 für Screenshot, Esc für Ende.
Viel Spaß damit!
Spoiler anzeigen
#include <Constants.au3>
#include <GUIConstantsEx.au3>
#include <WindowsConstants.au3>
#include <ScreenCapture.au3>
Opt("GUIOnEventMode", 1)
[/autoit] [autoit][/autoit] [autoit]Global $xStart = 0, $yStart = 0, $xStopp = 0, $yStopp = 0
Global $title = 'Screenshot markieren'
If Not IsDeclared("SM_VIRTUALWIDTH") Then Global Const $SM_VIRTUALWIDTH = 78
If Not IsDeclared("SM_VIRTUALHEIGHT") Then Global Const $SM_VIRTUALHEIGHT = 79
Global $VirtualDesktopWidth = DllCall("user32.dll", "int", "GetSystemMetrics", "int", $SM_VIRTUALWIDTH)
$VirtualDesktopWidth = $VirtualDesktopWidth[0]
Global $VirtualDesktopHeight = DllCall("user32.dll", "int", "GetSystemMetrics", "int", $SM_VIRTUALHEIGHT)
$VirtualDesktopHeight = $VirtualDesktopHeight[0]
GUICreate($title, $VirtualDesktopWidth, $VirtualDesktopHeight, 0, 0, $WS_POPUP, BitOR($WS_EX_TOPMOST, $WS_EX_TOOLWINDOW))
GUIRegisterMsg(0x0201, '_WM_LBUTTONDOWN') ;$WM_LBUTTONDOWN
GUIRegisterMsg(0x0202, '_WM_LBUTTONUP') ;$WM_LBUTTONUP
;~ GUIRegisterMsg(0x0204, '_WM_RBUTTONDOWN') ;$WM_RBUTTONDOWN
WinSetTrans($title, "", 30)
[/autoit] [autoit][/autoit] [autoit]If Not FileExists(@ScriptDir & "\Screenshots") Then DirCreate(@ScriptDir & "\Screenshots")
Global $hGraphic = GUICtrlCreateGraphic(0, 0, $VirtualDesktopWidth, $VirtualDesktopHeight)
GUICtrlSetBkColor(-1, 0xffffff)
GUICtrlSetState(-1, $GUI_DISABLE)
GUICtrlSetGraphic(-1, $GUI_GR_PENSIZE, 2)
GUISetState()
HotKeySet('{F9}', '_Make_Screenshot')
HotKeySet('{ESC}', '_quit')
While 1
Sleep(100000)
WEnd
Func _quit()
Exit
EndFunc ;==>_quit
Func _WM_LBUTTONDOWN($hWnd, $msg, $wParam, $lParam)
Local $fwKeys = $wParam, $xPos = BitAND($lParam, 0xFFFF), $yPos = BitShift($lParam, 16)
GUICtrlSetGraphic($hGraphic, $GUI_GR_COLOR, 0xffffff)
GUICtrlSetGraphic($hGraphic, $GUI_GR_RECT, $xStart, $yStart, $xStopp - $xStart, $yStopp - $yStart)
;~ GUICtrlSetGraphic($hGraphic, $GUI_GR_REFRESH)
$xStart = $xPos
$yStart = $yPos
Return $GUI_RUNDEFMSG
EndFunc ;==>_WM_LBUTTONDOWN
Func _WM_LBUTTONUP($hWnd, $msg, $wParam, $lParam)
Local $fwKeys = $wParam, $xPos = BitAND($lParam, 0xFFFF), $yPos = BitShift($lParam, 16)
$xStopp = $xPos
$yStopp = $yPos
GUICtrlSetGraphic($hGraphic, $GUI_GR_COLOR, 0x0)
GUICtrlSetGraphic($hGraphic, $GUI_GR_RECT, $xStart, $yStart, $xStopp - $xStart, $yStopp - $yStart)
GUICtrlSetGraphic($hGraphic, $GUI_GR_REFRESH)
Return $GUI_RUNDEFMSG
EndFunc ;==>_WM_LBUTTONUP
;~ Func _WM_RBUTTONDOWN($hWnd, $msg, $wParam, $lParam)
;~ Local $fwKeys = $wParam, $xPos = BitAND($lParam, 0xFFFF), $yPos = BitShift($lParam, 16)
;~ GUICtrlSetGraphic($hGraphic, $GUI_GR_COLOR, 0xffffff)
;~ GUICtrlSetGraphic($hGraphic, $GUI_GR_RECT, $xStart, $yStart, $xStopp - $xStart, $yStopp - $yStart)
;~ GUICtrlSetGraphic($hGraphic, $GUI_GR_REFRESH)
;~ Return $GUI_RUNDEFMSG
;~ EndFunc ;==>_WM_RBUTTONDOWN
Func _Make_Screenshot()
Local $x1, $x2, $y1, $y2
Select
Case $xStart < $xStopp
$x1 = $xStart
$x2 = $xStopp
Case $xStart > $xStopp
$x1 = $xStopp
$x2 = $xStart
EndSelect
Select
Case $yStart < $yStopp
$y1 = $yStart
$y2 = $yStopp
Case $yStart > $yStopp
$y1 = $yStopp
$y2 = $yStart
EndSelect
If $x1 > 0 And $x2 > 0 And $y1 > 0 And $y2 > 0 Then _ScreenCapture_Capture(@ScriptDir & "\Screenshots\Screenshot" & @YEAR & @MDAY & @WDAY & "_" & @HOUR & @MIN & @SEC & ".jpg", $x1, $y1, $x2, $y2, False)
EndFunc ;==>_Make_Screenshot
;~ MK_LBUTTONUP The left mouse button is up. --> 0x00
;~ MK_LBUTTON The user pressed the left mouse button. --> 0x01
;~ MK_RBUTTON The user pressed the right mouse button. --> 0x02
;~ MK_SHIFT The user pressed the SHIFT key. --> 0x04
;~ MK_CONTROL The user pressed the CTRL key. --> 0x08
;~ MK_MBUTTON The user pressed the middle mouse button. --> 0x10
