Xy dng m hnh t ng ho thit k trong AutoCad bng ngn ng lp trnh VB6 Phan T Hng, Trng i hc Kin trc H Ni Tm tt: Trong lnh vc thit k cng trnh xy dng, phn mm AutoCad c s dng rt ph bin v nhiu tnh nng u vit. Vi yu cu thit k i hi cht lng ngy cng cao, nhiu cng vic phi giao tip vi cc phn mm ng dng bn ngoi hoc thc hin lp i lp li, mt nhiu cng sc v d mc sai st. Cng vic c th hon ton thc hin t ng vi thi gian ngn, chnh xc cao nh ngn ng lp trnh VB6 (Visual Basic 6) trong mi trng AutoCad. Bi bo ny trnh by m hnh t ng ho thit k trong AutoCad bng ngn ng lp trnh VB6. M hnh t ng ho ny c ng dng trong nhiu phn mm thit k xy dng hin nay, nhng ti liu vit v m hnh lin kt ny rt him, k c cc ti liu nc ngoi. Hy vng bi bo ny s p ng nhu cu nhng ai mun tm hiu lnh vc t ng ho trong AutoCad bng VB6. 1. t vn AutoCad l phn mm chuyn v lnh vc v k thut v ho, c ng dng rt ph bin trong thit k cng trnh. Bn thn AutoCad c tch hp ngn ng lp trnh Visual Lisp v VBA (Visual Basic for Applications) nhng u c nhng hn ch nht nh. V d nh kh nng bo mt km, khng c kh nng ng gi thnh ng dng chy c lp, h tr t iu khin ActiveX,... Hai ngn ng ny thng c s dng vi cc ng dng quy m va v nh, hoc ng vai tr kt ni ng dng khc trong AutoCad. VB6 khc phc c nhng mt hn ch trn, c th to ra ng dng trong AutoCad hon ton chy c lp (khng ph thuc vo phin bn), sn phm c kh nng thng mi. Nhn chung cu trc, m lnh trong th tc ca VB6 v VBA rt ging nhau nn d dng tham kho v so snh. Ngun ti liu hng dn VBA trong 1

AutoCad cng kh phong ph. V vy, nhng ngi am hiu v VBA th c th nhanh chng tip cn, s dng VB6 v ngc li. Hin nay, tuy c thay th bng VB.NET nhng VB6 vn c s dng rng ri nh nhng u im trn. 2. iu khin AutoCad t VB6 VB6 c th to ra hn 6 kiu ng dng, nhng ch c hai kiu iu khin c vi AutoCad (v c cc phn mm trong Office) l Standard EXE v ActiveX DLL. Standard EXE l ng dng c bin dch chy hon ton c lp, iu khin AutoCad thng qua i tng Automation. Automation l mt dng cng ngh ActiveX trong gia nh Microsoft, cho php iu khin cc ng dng (AutoCad) t mi trng bn ngoi (nh VB6).VB6

AUTOMATION

Word

Excel

PowerPoi nt

AutoCad

Hnh 1: M hnh trao i d liu vi cc ng dng khc t VB6

Hnh 2: To ng dng Standard EXE 2

ActiveX DLL c hiu l th vin lin kt ng (Dynamic Link Library - DLL) cc ng dng c th tham chiu, s dng c. Khc vi VB6, VBA l mi trng lp trnh c sn trong AutoCad nn iu khin khng thng qua i tng Automation (c gi l AutoCAD.Application). iu c ngha Automation l i tng trung gian VB6 t bn ngoi c th iu khin cc ng dng khc nh AutoCad, Excel, Word,... Bi bo ny gii thiu 2 ng dng iu khin AutoCad t VB6 qua Standard EXE v ActiveX DLL mt cch n gin nht. 2.1. iu khin AutoCad bng Standard EXE Khi ng VB6, chn Standard EXE trong ca s New Project (hnh 2). D n (project) mi mc nh sn c Form1, chng ta i tn ca d n thnh VB6exeAcad, i tn Form thnh ControlAcad v lu li d n .

Hnh 3: Xy dng cc iu khin trong d n VB6exeAcad Sau , xy dng cc iu khin chnh nh hnh 3. iu khin Text Box gm c txtFirstX, txtFirstY (to im u), txtSecondX, txtSecondY (ta im cui). iu khin CommandButton gm c cmdFirstP, cmdSecondP (chn im u, im cui), cmdOK (thc hin lnh v), cmdClose (ng ca s),... Th tc di y s khi ng AutoCad khi Form ControlAcad c ti: 3

Private Sub Form_Load() On Error Resume Next 'B qua li khi AutoCad cha m sn '"Bt" i tng AutoCad nu ang m Set AcadApp = GetObject(, "AutoCAD.Application") 'Xo li nu AutoCad cha m If Err 0 Err.Clear End If AppActivate AcadApp.Caption 'Kch hot AutoCad AcadApp.Visible = True End Sub 'Hin ca s AutoCad 'Xo li pht sinh Set AcadApp = CreateObject("AutoCAD.Application")

Th tc thi hnh mt s nt lnh cmdClose, cmdFirstP, cmdSecondP nh hnh 4.

Hnh 4: Ni dung th tc ca nt lnh cmdClose, cmdFirstP, cmdSecondP Ni dung th tc ca nt cmdOK (v on thng t im LineP1 v LineP2):Private Sub cmdOK_Click() Dim LineL As Object, LineP1(0 To 2) As Double, LineP2(0 To 2) As Double With Me LineP1(0) = Val(.txtFirstX) LineP1(1) = Val(.txtFirstY) LineP2(0) = Val(.txtSecondX) 'Gn to im cui 'Gn to im u

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LineP2(1) = Val(.txtSecondY) End With 'V on thng v chuyn sang mu Set LineL = AcadApp.ActiveDocument.ModelSpace.AddLine(LineP1, LineP2) LineL.Color = 1 Unload Me Set AcadApp = Nothing End Sub 'Xo bin i tng

i tng AcadApp c khai bo trn chnh l AutoCAD.Application. Nu AutoCad ang m, s dng hm GetObject chng trnh tham chiu n i tng AutoCAD.Application. Trong trng hp AutoCad cha m, s dng hm CreateObject to ra v tr v tham chiu n i tng AutoCAD.Application. Sau khi xy dng hon chnh, bn vo menu File v chn Make VB6exeAcad.exe... to file chy c lp nh cc chng trnh khc. ng dng ny c th thc hin trn cc phin bn AutoCad bt u t 2000 (phin bn u tin h tr Automation). 2.2. iu khin AutoCad bng ActiveX DLL Khi ng VB6, chn ActiveX DLL trong ca s New Project (hnh 2). D n mi mc nh c mt Class Module, i tn ca d n thnh Dll_VB6_Project v lu li d n . Sau thm Form, Module, Class Module bng cch vo menu Project v chn Add Form, Add Module, Add Class Module (hnh 5).

Hnh 5: Ti Form, Module vo d n Dll_VB6_Project D n Dll_VB6 c ba thnh phn l Form FDllVb6, Module Dll_in_AutoCad, Class Module HelloDllVB6 nh sau: 5

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Module Dll_in_AutoCad: Khai bo bin i tng CadApp, chnh l i tng Acad.Application cc th tc c th truy cp.

Public CadApp As Object (gi chung)

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Form FDllVb6: L Form s hin th trong AutoCad, Form ny cha cc iu khin theo mun. Phng php xy dng cc iu khin tng t nh mc 2.1 nn khng trnh by li na.

Private Sub cmdLine_Click() Dim LineObj As Object Dim StartPoint As Variant Dim EndPoint As Variant On Error GoTo Thoat 'T thot khi gp li hay bm phm Esc Unload Me 'Chn im u ca ng thng StartPoint = CadApp.ActiveDocument.Utility.GetPoint(, "Chon diem dau:") Do 'Chn im cui ca ng thng, c lp ging lnh Line trong AutoCad EndPoint = CadApp.ActiveDocument.Utility. _ GetPoint(StartPoint, "Chon diem tiep theo:") 'V on thng Set LineObj = CadApp.ActiveDocument.ModelSpace. _ AddLine(StartPoint, EndPoint) 'Gn bin i tng StartPoint = EndPoint Loop Set LineObj = Nothing Thoat: End Sub

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Class Module HelloDllVB6: To i tng mi c tn HelloDllVb6, trong HelloDllVb6 xy dng th tc ShowVB6Form (hnh 7). Th tc ShowVB6Form c chc nng hin th form FDllVb6 trong AutoCad.

ng ch trong d n ny c s dng hai hm API l FindWindowA v SetWindowLongA. Hm FindWindowA ly handle ca ca s c tn (title) c ch

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nh. Hm SetWindowLongA s thay i thuc tnh ca ca s ch nh (xem thm trong trang www.microsoft.com).

Hnh 6: Cu trc D n Dll_VB6_Project

Hnh 7: Cu trc Class Module HelloDllVB6 7

Hnh 8: Bin dch d n Dll_VB6_Project sang DLL Khi d n hon thnh, chng ta tin hnh bin dch bng cch chn menu File\ Make Dll in AutoCad.dll... (hnh 8). By gi, cng vic tip theo ca chng ta l s dng file "Dll in AutoCad.dll" nh th no? Khc vi VB6exeAcad.exe c th iu khin trc tip AutoCad, s dng ActiveX DLL cn phi c th tc trong AutoCad gi ng dng . Th tc c xy dng bng VBA hoc AuoLisp trong AutoCad.

Hnh 9: Ca s Microsoft Visual Basic trong AutoCad u tin chng ta khi ng AutoCad, sau vo menu Tools\ Macro\ Visual Basic Editer (hoc bm Alt+F11). Ca s Microsoft Visual Basic hin ra (hnh 9), chn menu Insert\ Module thm module mi. Sau vo menu Tools\ References..., ca s References - ACADProject hin ra nh hnh 10. Bm vo nt Browse... tm file "Dll in AutoCad.dll" va c bin dch. Khi chn xong, AutoCad xc nhn d n Dll_VB6_Project c ti vo chng trnh (hnh 10). 8

Hnh 10: Dll in AutoCad.dll c np trong AutoCad Sau chng ta tin hnh xy dng th tc DisplayDLLForm trong VBA, d n va ri c np vo Auto List Members nh cc thnh phn sn c trong AutoCad (hnh 11).

Hnh 11: D n Dll_VB6_Project c xc nhn trong Auto List Members Th tc DisplayDLLForm hon chnh nh di:Public Sub DisplayDLLForm() 'Khai bo bin HelloDllVb6 trong Dll_VB6_Project Dim HelloDllVb6 As Dll_VB6_Project.HelloDllVb6 Set HelloDllVb6 = New Dll_VB6_Project.HelloDllVb6 Set HelloDllVb6.AcadApp = Application 'Hin thi hnh th tc ShowVB6Form ti form FDllVb6 HelloDllVb6.ShowVB6Form Set HelloDllVb6 = Nothing End Sub

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Hnh 12: Thi hnh th tc DisplayDLLForm trong AutoCad

Hnh 13: Form xy dng trong VB6 trong AutoCad Trong th tc trn, HelloDllVb6 ng vai tr l mt i tng nm trong Dll_VB6_Project. i tng HelloDllVb6 c phng thc ShowVB6Form. Sau thi hnh th tc trn bng cch chuyn sang ca s AutoCad, vo menu Tools\ Macro\ Macros... (hoc phm tt Alt+F8). Ca s Macros hin ra nh hnh 12, chn th tc DisplayDLLForm v bm nt Run. Kt qu th hin nh hnh 13 thi hnh cc lnh.

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Hnh 14: Form xy dng trong VBA ca AutoCad 3. Quan h gia VB6 v VBA trong AutoCad Nh cp trn, VB6 v VBA rt gn gi nhau v chng u l ngn ng lp trnh Visual Basic. Khi lm vic vi i tng ging nhau, cch thc thc hin tng t nhau. tin so snh, chng xy dng thm Form v on thng trong VBA ging nh trong VB6 (hnh 14). Cc i tng bn trong Form cng nh thuc tnh ca chng thit lp gn tng t nhau. Giao din gia 2 chng trnh ging nhau n mc c th gy nn s xo trn khi lm vic vi chng (hnh 6 v 14). V mt thut ton cng nh m lnh (code) gia chng gn tng t nhau. tin so snh chng ta copy ton b code v on thng trong VB6 (hnh 6) sang VBA (hnh 14). Do VBA c sn trong AutoCad (khng phi can thip t bn ngoi nh VB6) nn ch cn b i on code CadApp., cn ton b gi nguyn. Th tc v on thng trong VBA sa li nh sau:Private Sub cmdLine_Click() Dim LineObj As Object Dim StartPoint As Variant Dim EndPoint As Variant

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On Error GoTo Thoat ' T thot khi gp li hay bm phm Esc Unload Me 'Chn im u ca ng thng StartPoint = ActiveDocument.Utility.GetPoint(, "Chon diem dau:") Do 'Chn im cui ca ng thng, c lp ging lnh Line trong AutoCad EndPoint = ActiveDocument.Utility. GetPoint(StartPoint, "Chon diem tiep theo:") 'V on thng Set LineObj = ActiveDocument.ModelSpace.AddLine(StartPoint, EndPoint) 'Gn bin i tng StartPoint = EndPoint Loop Set LineObj = Nothing Thoat: End Sub

Hy kim tra th tc trn, chng ta s thy kt qu tng t nh vi VB6. l cch chuyn code t VB6 sang VBA, cn nu mun chuyn t VBA sang VB6 th thc hin ngc li bng cch b sung ng dn CadApp. trn. iu tht n gin phi khng?! Ti sao chng ta li quan tm n mi lin quan gia VB6 v VBA? Sch hng dn lp trnh VB6 iu khin cc i tng bn ngoi, c bit l AutoCad l rt him hoc ch dn mt cch s si. Trong khi , ngun ti liu hng dn s dng VBA trong AutoCad li kh phong ph trn Internet cng nh c sn trong phn Help ca AutoCad. Trong AutoCad 2007, vo menu Help\Additional Resources\ Developer Help, ca s AutoCad 2007 Help: Developer Documentation hin ra nh hnh 15. Khai thc nhng thng tin trong chng ta s thu c nhiu kin thc VBA vi nhng ch dn c th vi v d km theo. V nh vy, tr thnh chuyn gia lp trnh VB6 cho i tng AutoCad (hay Office), cn c bc m nghin cu v s dng thnh tho VBA. Khi th tc vit trong VBA chy chun, ch cn vi thao tc sao chp, b sung n gin l code VBA tr thnh code VB6.

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Hnh 15: Tr gip v ActiveX v VBA 4. Kt lun - Visual Basic ang dn dn thay th lp trnh Pascal trong mn Tin hc i cng trong mt s trng i hc (khng chuyn v Tin hc) v tnh trc quan, sn phm ng dng mang li hiu qu. - Vi sinh vin (k s) cc trng k thut, phn mm AutoCad v Office c s dng ph bin. V vy nhu cu t ng ho trong cc phn mm l tt yu, nng cao kh nng ng dng Cng ngh thng tin trong chuyn mn. - Bi bo ny l c s xy dng phn mm trong AutoCad t ngn ng lp trnh VB6. T nh hng xy dng cc phn mm ng dng trong AutoCad chuyn nghip hn, mnh m hn nh Visual Studio Tools for Applications (VSTA), VC++ to ObjectARX (AutoCAD Runtime Extension) trong VB.NET.

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Building Automatical Designing Models for AutoCAD with VB6 Programming Language Phan Tu Huong, Hanoi Architectural University Abstract: AutoCAD is intensively used for construction design because of many significant advantages. The high demand of designing work requires activities which may interference with other software or repeating. Doing these activities manually may cause a lot of human force and can easily make mistakes. The problem can be solved in short time and with high accuracy by using VB6 Programming Language (Visual Basic 6) in the environment of AutoCAD. The paper presents the procedure to build automatically designing models for AutoCAD with VB6 programming language. The models are currently used for several designing software. However the manual in this field is still very limited, even though the foreign documents. The paper hopes to bring the first insights for those who would like to know about automatical models in AutoCAD with the help of VB6. TI LIU THAM KHO [1]. Phan T Hng, 2006. ng dng ngn ng VBA trong Excel gii mt s bi ton trong a cht cng trnh. Tp ch khoa hc M - a cht. [2]. Stephen Bullen, Rob Bovey, John Green, 2005. Professional Excel Development: The Definitive Guide to Developing Applications Using Microsoft Excel and VBA. Addison Wesley Professional. [3]. Autodesk, 2003. ActiveX and VBA Developers Guide. M&T Books. [4]. Phan T Hng, 2010. Lp trnh VBA trong Excel (ti bn ln th 2). Nh xut bn thng k. [5]. Joe Sutphin, 2005. AutoCAD 2006 VBA A Programmers Reference. Apress books. [6]. Chi tit d n xem ti y http://www.cadviet.com/forum/index.php?showtopic=10922

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