XProfan

 $H windows.ph
 $H messages.ph
 $H commctrl.ph
Struct S_RECT      = left&,top&,right&,bottom&
Struct S_MOUSE     = mx&,my&
Declare tabcontrol&,_hIL%,_ende%,_MaxTab%,hFont%,AktTab%
Declare draggedTab&
draggedTab& = -1
Declare mouse#
Dim mouse#, S_MOUSE

SubClassProc

    Declare   i%,o%, rect#, tabrect#, xPressed&, tabPressed&
    Dim rect#, S_RECT
    Dim tabrect#, S_RECT

    If SubClassMessage(Tabcontrol&, ~WM_LBUTTONDOWN) OR SubClassMessage(Tabcontrol&, ~WM_LBUTTONUP)

        ~GetCursorPos(mouse#)
        ~GetWindowRect(Tabcontrol&,tabrect#)

        WhileLoop 0, _MaxTab%

            sendmessage(Tabcontrol&,~TCM_GETITEMRECT,&loop,rect#)

            If &loop < _MaxTab%

                xPressed&   = (mouse#.mx& >= rect#.right&-16-2+tabrect#.left&) AND (mouse#.mx&<=rect#.right&+tabrect#.left&) AND (mouse#.my&>=rect#.top&+tabrect#.top&) AND (mouse#.my&<=rect#.top&+16+tabrect#.top&)
                tabPressed& = (mouse#.mx& >= (rect#.left&+tabrect#.left&)) AND (mouse#.mx& <= (rect#.right&+tabrect#.left&)) AND (mouse#.my& >= (rect#.top&+tabrect#.top&))  AND (mouse#.my& <= (rect#.bottom&+tabrect#.top&))

                If xPressed& AND SubClassMessage(Tabcontrol&, ~WM_LBUTTONUP)

                    sendmessage(Tabcontrol&,~TCM_DELETEITEM,&loop,0)
                    Dec _MaxTab%
                    SendMessage(TabControl&,~TCM_SETCURSEL,if(&loop - 1 > 0, &loop-1, 0),0)' aktiviert Tab
                    Break

                EndIf

                If tabPressed& AND not(xPressed&)

                    If SubClassMessage(Tabcontrol&, ~WM_LBUTTONDOWN)

                        draggedTab& = &loop

                    Else

                        draggedTab& = -1

                    EndIf

                EndIf

            EndIf

        EndWhile

    EndIf

    Dispose rect#, tabrect#

EndProc'SUBCLASSPROC

'Hauptprogramm:
Cls
hFont% = Create("Font","segoe ui",16,0,0,0,0)
SetDialogFont  hFont%
UserMessages $10
Tabcontrol&=Create("TABCTRL",%HWnd,_hIL%,0,32,width(%HWnd),24)
SubClass Tabcontrol&,1
set("FASTMODE",1)
inserttab(Tabcontrol&,0,"Tab 1  × ")
inserttab(Tabcontrol&,1,"Tab 2  × ")
inserttab(Tabcontrol&,2,"Tab 3  × ")
inserttab(Tabcontrol&,3,"Tab 4  × ")
inserttab(Tabcontrol&,4,"Tab 5  × ")
set("FASTMODE",0)
_MaxTab% = 5

Proc DragTab

    Declare deskImg&, tabImg&, tabImgList&, mouse2#, rect#, tabrect#, temp$, tabPressed&, min&, max&, droppedTab&
    Declare BorderWidth&, BorderHeight&, TitleHeight&, MenuBarHeight&, ClientRect#,WindowRect#
    Dim WindowRect#,S_RECT
    Dim ClientRect#,S_RECT
    Dim mouse2#, S_MOUSE
    Dim rect#, S_RECT
    Dim tabrect#, S_RECT
    ~GetCursorPos(mouse2#)
    ~GetWindowRect(Tabcontrol&,tabrect#)
    ~GetWindowRect(%hwnd,WindowRect#)
    ~GetClientRect(%hwnd,ClientRect#)
    BorderWidth&   = (WindowRect#.right& - WindowRect#.left& - ClientRect#.right&) / 2
    BorderHeight&  = (WindowRect#.bottom& - WindowRect#.top& - ClientRect#.bottom& - BorderWidth&)
    'TitleHeight&   = ~GetSystemMetrics(~SM_CYCAPTION)
    'MenuBarHeight& = ~GetSystemMetrics(~SM_CYMENU)

    If (mouse2#.mx& = mouse#.mx&) AND  (mouse#.my& = mouse2#.my&)

        Return

    EndIf

    'Es ist komplex, trotzdem wohl der von Windows vorgesehene Weg: man schnippelt sich das Tab-Bild selbst aus einem Screenshot aus und baut dann eine 1-Bild Imagelist
    'C++ hat in der afxcmn.h eine Funktion CreateDragImage, die letztendlich aber auch nur den Weg über die Imagelist geht
    Sendmessage(Tabcontrol&,~TCM_GETITEMRECT,draggedTab&,rect#)
    deskImg&   = Create("hPic",0,"&SCRBMP")'&DSKBMP war einfacher von der Koordinatenberechnung her, funktionierte aber nur auf dem Hauptbildschirm
    tabImg&    = Create("hPicCopy", deskImg&, \
    tabrect#.left&+rect#.left& - (WindowRect#.left&  + BorderWidth&),\
    tabrect#.top&+rect#.top&   - (WindowRect#.top&  + BorderHeight&),\
    rect#.right&-rect#.left&,\
    rect#.bottom& - rect#.top&)
    tabImgList& = create("ImageList",  rect#.right&-rect#.left&, rect#.bottom&-rect#.top&, tabImg&,-1)
    DeLeteObject tabImg&, deskImg&
    ~ImageList_BeginDrag(tabImgList&,0,%winleft,%wintop)
    ~ImageList_DragEnter(%hwnd,0,0)

    While ~GetAsyncKeyState(1)

        ~GetCursorPos(mouse2#)
        ~ImageList_DragMove(mouse2#.mx&,mouse2#.my&)

    EndWhile

    WhileLoop 0, _maxtab%

        SendMessage(Tabcontrol&,~TCM_GETITEMRECT,&loop,rect#)
        tabPressed& = (mouse2#.mx& >= (rect#.left&+tabrect#.left&)) AND (mouse2#.mx& <= (rect#.right&+tabrect#.left&)) AND (mouse2#.my& >= (rect#.top&+tabrect#.top&))  AND (mouse2#.my& <= (rect#.bottom&+tabrect#.top&))
        droppedTab& = &loop

        If tabPressed& AND  (droppedTab& <> draggedTab&)

            'Tabs aufrücken, je nachdem ob nach links oder nach rechts gedropped wurde
            'Hier müsste neben dem Tab-Text natürlich auch der Tabinhalt ausgetauscht werden

            If droppedTab& >  draggedTab&

                temp$ = GetText$(tabcontrol&,draggedTab&)

                WhileLoop draggedTab&, droppedTab& - 1

                    SetText Tabcontrol&,&loop,GetText$(tabcontrol&,&loop + 1)

                EndWhile

                SetText Tabcontrol&,droppedTab&,temp$

            Else

                temp$ = GetText$(tabcontrol&,draggedTab&)

                WhileLoop draggedTab&, droppedTab& + 1, -1

                    SetText Tabcontrol&,&loop,GetText$(tabcontrol&,&loop -1)

                EndWhile

                SetText Tabcontrol&,droppedTab&,temp$

            EndIf

            AktTab% = droppedTab&
            SendMessage(TabControl&,~TCM_SETCURSEL,AktTab%,0)' aktiviert Tab

        EndIf

    EndWhile

    ~ImageList_EndDrag()
    DeLeteObject  tabImgList&
    draggedTab& = -1
    Repaint 1
    Dispose mouse2#, rect#, tabrect#, ClientRect#, WindowRect#

EndProc

While _ende%=0

    Case draggedTab& = -1 : WaitInput'etwas unelegant, vielleicht findet jemand die richtige Message, notfalls mousemove

    If draggedTab& <> -1

        DragTab()

    EndIf

    If (%uMessage=$10) or ((~GetForegroundWindow()=%HWnd) and iskey(27))

        While iskey(27)

            Sleep 25

        EndWhile

        _ende%=1

    EndIf

EndWhile

SubClass Tabcontrol&,0
UserMessages 0
End