Tools for the VBA User

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1 11/30/2005-3:00 pm - 4:30 pm Room:Mockingbird 1/2 [Lab] (Swan) Walt Disney World Swan and Dolphin Resort Orlando, Florida R. Robert Bell - MW Consulting Engineers and Phil Kreiker (Assistant); Darren Young (Assistant) CP34-1L This class is about enhancing our knowledge of basic VB tools, such as file management and input/output, Windows APIs, such as registry settings and INI files, to secure information. We will also look at connecting to other applications and get to know the object model. About the Speaker: Robert is the network administrator for MW Consulting Engineers, a consulting firm in Spokane, Washington, where he is responsible for the network and all AutoCAD customization. Robert has been writing AutoLISP code since AutoCAD v2.5, and VBA since it was introduced in Release 14. He has customized applications for the electrical/lighting, plumbing/piping, and HVAC disciplines. Robert has also developed applications for AutoCAD as a consultant. He is on the Board of Directors for AUGI and is active on Autodesk discussion groups. RobertB@MWEngineers.com

Introduction AutoCAD s object model provides you with the tools you need to work with a drawing itself. However, quite often you need to perform tasks that do not relate directly to a drawing.

APIs can help you store and access data. Transferring data from a drawing into a Microsoft Office Excel spreadsheet can be simple in VBA. The following exercises will introduce these features to you.

3 Introduction AutoCAD s object model provides you with the tools you need to work with a drawing itself. However, quite often you need to perform tasks that do not relate directly to a drawing. VBA can access so much more than just AutoCAD. You should use the Microsoft Windows APIs to avoid reinventing the wheel for tasks such as browsing for folders or opening files. APIs can help you store and access data. Transferring data from a drawing into a Microsoft Office Excel spreadsheet can be simple in VBA. The following exercises will introduce these features to you. Working with Files and Folders VBA provides limited support for manipulating files and folders. However, there is an easy way to perform tasks such as copying, moving, deleting, and retrieving both files and folders. Microsoft provides the File System Object that is part of the Scripting type library. The File System Object is made available when you add a reference to Microsoft Scripting Runtime. Please note that if you need high performance for file operations, the scripting run-time is not the best choice. However, for simple, small tasks the scripting run-time makes such operations easy. Load the VBA project C:\datasets\CP34-1L\FSO Sample.dvb Add a reference to Microsoft Scripting Runtime Take a few moments to browse the Scripting library. Note the different methods related to files and folders. The following is supporting code for the lab exercises. Option Explicit Const SampleFName As String = "\FSO Sample.txt" Const CopyFName As String = "\FSO Sample (copy).txt" Enum fsospecialfolders fsowindowsfolder fsosystemfolder fsotemporaryfolder End Enum Private Function GetDriveType(fsoDriveType As Long) As String Select Case fsodrivetype Case 0: GetDriveType = "Unknown" Case 1: GetDriveType = "Removable" Case 2: GetDriveType = "Fixed" Case 3: GetDriveType = "Network" Case 4: GetDriveType = "CD-ROM" Case 5: GetDriveType = "RAM Disk" End Select End Function It is time to add some code to the incomplete procedures in the loaded project. After you add the required code, position your cursor inside the edited procedure and use the F8 key to execute the code line-by-line. 2

4 Exercise 1. Getting an existing folder Function GetTempFolder() As String Dim myfso As FileSystemObject Set myfso = New FileSystemObject Dim mytemp As Folder Set mytemp = myfso.getspecialfolder(fsotemporaryfolder) GetTempFolder = mytemp.path Set myfso = Nothing End Function Exercise 2. Creating a text-based file Sub CreateTextFile() Dim myfso As FileSystemObject Set myfso = New FileSystemObject Dim myfilename As String myfilename = GetTempFolder & SampleFName Creating a New Object The procedure for creating an instance of an object defined by a referenced library is straightforward. You need to declare a variable of the type of object, e.g.: Dim myobject As You then need to create a new instance of the object using the Set statement, e.g.: Set myobject = New Dim myfile As File myfso.createtextfile myfilename, True Set myfile = myfso.getfile(myfilename) MsgBox "Created: " & myfile.datecreated Set myfso = Nothing Exercise 3. Copying a file Sub CopyFile() Dim myfso As FileSystemObject Set myfso = New FileSystemObject Dim myfilename As String myfilename = GetTempFolder & SampleFName Closing Your Objects Objects should be set to Nothing automatically when a procedure is complete. This is called going out of scope. However, you may have fewer issues with your programs when you explicitly set objects created with the New keyword to Nothing at the end of their useful life. Dim copyfilename As String copyfilename = GetTempFolder & CopyFName If myfso.fileexists(myfilename) Then myfso.copyfile myfilename, copyfilename, True Set myfso = Nothing 3

5 Exercise 4. Listing the contents of a folder Sub ListTempFolder() Dim myfso As FileSystemObject Set myfso = New FileSystemObject Dim myfolder As Folder Set myfolder = myfso.getfolder(gettempfolder) Dim afile As File For Each afile In myfolder.files If afile.name Like "*.txt" Then Debug.Print afile.name Next afile Set myfso = Nothing Exercise 5. Deleting a file Sub DeleteFile() Dim myfso As FileSystemObject Set myfso = New FileSystemObject Dim myfilename As String myfilename = GetTempFolder & CopyFName If myfso.fileexists(myfilename) Then myfso.deletefile myfilename ListTempFolder Set myfso = Nothing Exercise 6. Listing available drives Sub ListDrives() Dim myfso As FileSystemObject Set myfso = New FileSystemObject Dim mydrives As Drives Set mydrives = myfso.drives Dim adrive As Drive For Each adrive In mydrives Debug.Print adrive.driveletter & ", type: " & GetDriveType(aDrive.DriveType) Next adrive Set myfso = Nothing 4

$However, instead of adding many lines of code to access the API, simply add a reference to the shell. Load the VBA project C:\datasets\CP34-1L\Select Dialogs Sample.$

6 Selecting a folder Selecting a folder in a dialog box does not need to be complicated. In fact, it is far easier than many people make it. The usual approach is to use the Win32 API. However, instead of adding many lines of code to access the API, simply add a reference to the shell. Load the VBA project C:\datasets\CP34-1L\Select Dialogs Sample.dvb Add a reference to Microsoft Shell Controls And Automation Exercise 7. Get a folder from a browsing dialog Sub GetFolder() Dim myshell As Shell Set myshell = New Shell Dim myfolder As Folder3 Set myfolder = myshell.browseforfolder(0, "Get folder", 0) If Not (myfolder Is Nothing) Then Debug.Print myfolder.self.path Set myshell = Nothing Execute the procedure a few times, observing the results. Also, use the Cancel button during your testing. Selecting files As easy as it is to select an existing folder, it is not as easy to do the same with files. You need to use the Win32 API. For a sample of just some of the code required, use the Win32 API Common Dialog shortcut located in the C:\datasets\CP34-1L folder, which takes you to a Microsoft Knowledge Base article. Happily, many programmers were tired of working with the complex code and decided to encapsulate it into a class module for easy reuse. A search of the Internet will reveal many such class modules. For the purpose of this lab, one such class module will be used. This class module was downloaded from and slightly modified to permit easier code maintenance. Note that the original copyright needs to remain with the class module if you choose to use it for your own projects. Add a reference to C:\datasets\CP34-1L\CommonDialog.dvb Exercise 8. Get files from a browsing dialog Sub GetFile() Dim mydialog As CommonDialogProject.CommonDialog Set mydialog = CommonDialogProject.Init mydialog.filter = "Drawing (*.dwg) *.dwg" mydialog.flags = OFN_ALLOWMULTISELECT + OFN_EXPLORER + OFN_FILEMUSTEXIST + OFN_PATHMUSTEXIST mydialog.maxfilesize = 512 mydialog.initdir = ThisDrawing.GetVariable("DwgPrefix") 5

Dim Success As Long Success = mydialog.showopen If Success > 0 Then Dim DwgFiles As Variant DwgFiles = mydialog.parsefilenames Dim i As Long For i = 0 To UBound(DwgFiles) Debug.

7 Dim Success As Long Success = mydialog.showopen If Success > 0 Then Dim DwgFiles As Variant DwgFiles = mydialog.parsefilenames Dim i As Long For i = 0 To UBound(DwgFiles) Debug.Print DwgFiles(i) Next i The first two added lines are used to create the object defined by the referenced project s class module. Notice how the project s name must be included when using a referenced VBA project s procedures. The remaining added code affects what is displayed in the dialog and what the user can select. Experiment with changing some of the values of the properties. Reading and writing to.ini files Initialization files (.ini) are what many would consider ancient technology. After all, they were used heavily in Windows 3.0! However, they still have their uses. They are a simple text-based file with simple formatting rules. They are easy-to-use storage mechanisms for program settings and data. Four Win32 API functions give you access to reading and writing both sections and key values. Once again, the complexity of dealing with the API functions and data validation can be concealed behind a class module. The following exercises will use the class module to read and write data. Load the VBA project C:\datasets\CP34-1L\INI Sample.dvb Add a reference to C:\datasets\CP34-1L\INI Handler.dvb Exercise 9. Read a section from an.ini file Sub ReadASection() Dim myini As INIHandlerProject.INIHandler Set myini = INIHandlerProject.Init myini.filename = "C:\datasets\CP34-1L\Sample.ini" myini.section = "Project Info" Dim mysection As Scripting.Dictionary Set mysection = myini.getsection Dim i As Long For i = 0 To mysection.count - 1 Debug.Print mysection.item(i) Next i After you make the additions run the procedure and observe the results in the VBAIDE Immediate window. 6

8 Exercise 10. Read a specific key from an.ini file Sub ReadAKey() Dim myini As INIHandlerProject.INIHandler Set myini = INIHandlerProject.Init myini.filename = "C:\datasets\CP34-1L\Sample.ini" myini.section = "Project Info" myini.key = "JobName" Debug.Print myini.getkeyvalue myini.section = "Layers" myini.key = "Arch" Debug.Print myini.getkeyvalue Observe the results when you run the procedure. Change the key name to another key in the same section. Finally, the following code uses the class module to write some data to an.ini file. Exercise 11. Write data to an.ini file Sub WriteAKey() Dim myini As INIHandlerProject.INIHandler Set myini = INIHandlerProject.Init myini.filename = "C:\datasets\CP34-1L\Sample.ini" If myini.writekeyvalue("test Section", "Test Key", "Test Value") Then Debug.Print "Value was written!" Reading and writing to the registry The registry is the mechanism that most programs use to store configuration data to support the application. As many long-time users are aware, AutoCAD stores much information in the registry. However, there are factors you should consider before using the registry to store data. Microsoft has the following recommendations regarding the registry. Although there are few technical limits to the type and size of data an application can store in the registry, certain practical guidelines exist to promote system efficiency. An application should store configuration and initialization data in the registry, and store other kinds of data elsewhere. Generally, data consisting of more than one or two kilobytes (K) should be stored as a file and referred to by using a key in the registry rather than being stored as a value. Instead of duplicating large pieces of data in the registry, an application should save the data as a file and refer to the file. Executable binary code should never be stored in the registry. A value entry uses much less registry space than a key. To save space, an application should group similar data together as a structure and store the structure as a value rather than storing each of the structure members as a separate key. (Storing the data in binary form allows an application to store data in one value that would otherwise be made up of several incompatible types.) Give careful thought as to whether the registry is the best place to store data for your particular application. For instance, the registry should not be used to store data about specific drawings or projects. You do not want your registry to grow too large. The larger the registry, the more RAM is consumed by the operating system. 7

$The next series of exercises will write data to the registry and read that data back. Load the VBA project C:\datasets\CP34-1L\Reg Sample.$

9 The next series of exercises will write data to the registry and read that data back. Load the VBA project C:\datasets\CP34-1L\Reg Sample.dvb Add a reference to Windows Script Host Object Model Exercise 12. Write data to the registry Sub WriteToReg() Dim mywshshell As WshShell Set mywshshell = New WshShell mywshshell.regwrite "HKCU\Software\Autodesk University\CP34-1L\", _ "", _ "REG_SZ" mywshshell.regwrite "HKCU\Software\Autodesk University\CP34-1L\MyData", _ "Sample", _ "REG_SZ" Set mywshshell = Nothing Sub ReadReg() Dim mywshshell As WshShell Set mywshshell = New WshShell Debug.Print _ mywshshell.regread("hkcu\software\autodesk University\CP34-1L\MyData") Set mywshshell = Nothing The remainder of the course will cover interfacing with Microsoft Office Excel. The remainder of this page is intentionally left blank. 8

Interfacing with Microsoft Office Excel It is very common to desire that your data in AutoCAD were also in an external application such as Excel.

Just as AutoCAD s object model is located in AutoCAD s help files, so too is Excel s object model in Excel s help files.

10 Interfacing with Microsoft Office Excel It is very common to desire that your data in AutoCAD were also in an external application such as Excel. VBA and ActiveX make it much easier than you may suspect. The key is that you need to know not only the AutoCAD object model, but also the Excel object model. Just as AutoCAD s object model is located in AutoCAD s help files, so too is Excel s object model in Excel s help files. It is important to treat the Excel object model with respect when you interface with it from AutoCAD. You must make sure to close Excel s objects and set them to Nothing when finished with them. You must do this in reverse order of creation, i.e. Last In First Out (LIFO). The exercises in this section will use early binding, that is, a reference will be added to the VBA project to the Excel Object Library. This introduces the advantages of IntelliSense and a performance boost, at the expense of tying the project to a specific version of Excel. The alternative would be to use late binding, where no reference is added to the project and Excel s objects are declared as generic objects. Open the drawing C:\datasets\CP34-1L\Sample.dwg Load the VBA project C:\datasets\CP34-1L\Excel Sample.dvb Add a reference to Microsoft Excel 11.0 Object Library The following code is the front-end into the exercises. The ExportTBlk procedure is your test routine. You will be modifying the support procedures. Option Explicit Option Compare Text Sub ExportTBlk() Dim fqndata As String fqndata = "C:\datasets\CP34-1L\Sample.xls" Dim myexcel As Excel.Application Set myexcel = InitializeExcel Dim mybook As Excel.Workbook Set mybook = GetWorkbook(myExcel, fqndata) WriteTBlkData mybook mybook.close SaveChanges:=True Set mybook = Nothing myexcel.quit Set myexcel = Nothing MsgBox "Titleblock export is complete.", _ vbokonly, "Titleblock Data" 9

11 Exercise 13. Connect to Excel Private Function InitializeExcel() As Excel.Application If IsExcelRunning Then Set InitializeExcel = GetObject(, "Excel.Application") Else Set InitializeExcel = CreateObject("Excel.Application") End Function Private Function IsExcelRunning() As Boolean Dim xlapp As Excel.Application On Error Resume Next Set xlapp = GetObject(, "Excel.Application") IsExcelRunning = (Err.Number = 0) Set xlapp = Nothing Err.Clear End Function Exercise 14. Opening a workbook Private Function GetWorkbook(theApp As Excel.Application, Filename As String) As Workbook Dim myfso As Scripting.FileSystemObject Set myfso = New Scripting.FileSystemObject If myfso.fileexists(filename) Then Set GetWorkbook = theapp.workbooks.open(filename) Else Set GetWorkbook = theapp.workbooks.add WriteHeader GetWorkbook.ActiveSheet GetWorkbook.SaveAs Filename Set myfso = Nothing End Function Exercise 15. Writing data to Excel Private Sub WriteTBlkData(ByRef theworkbook As Workbook) Dim mydata As Collection Set mydata = GetTBLkData("Titleblock") With theworkbook.activesheet Dim myused As Excel.Range Set myused =.UsedRange Dim datarow As Long Dim dwgcell As Excel.Range Set dwgcell = myused.find(thisdrawing.name, LookIn:=xlValues) If dwgcell Is Nothing Then datarow = myused.rows.count + 1 Else datarow = dwgcell.row 10

12 .Cells(dataRow, 1).Value = ThisDrawing.Name.Cells(dataRow, 2).Value = mydata.item("sheetnumber").cells(datarow, 3).Value = GetTitle(myData).Cells(dataRow, 4).Value = mydata.item("drafter").cells(datarow, 5).Value = mydata.item("checker").cells(datarow, 6).Value = mydata.item("date").cells(datarow, 7).Value = mydata.item("revision").columns("a:g").autofit Set myused = Nothing End With The following code supports the prior code and requires no modification. Private Function GetTBLkData(Name As String) As Collection Dim aentity As AcadEntity For Each aentity In ThisDrawing.Layouts.Item("Layout1").Block If TypeOf aentity Is AcadBlockReference Then Dim tblk As AcadBlockReference Set tblk = aentity If tblk.name = Name Then Dim tblkattribs As Variant tblkattribs = tblk.getattributes Dim mytblk As Collection Set mytblk = New Collection Dim aattrib As AcadAttributeReference Dim i As Long For i = 0 To UBound(tBlkAttribs) Set aattrib = tblkattribs(i) mytblk.add aattrib.textstring, aattrib.tagstring Next i Exit For Next aentity Set GetTBLkData = mytblk End Function Private Function GetTitle(myData As Collection) As String Dim mytitle As String mytitle = mydata.item("sheettitle1") If mydata.item("sheettitle2") <> "" Then mytitle = mytitle & " " & mydata.item("sheettitle2") If mydata.item("sheettitle3") <> "" Then mytitle = mytitle & " " & mydata.item("sheettitle3") GetTitle = Replace(myTitle, " ", " ") End Function Private Sub WriteHeader(ByRef mysheet As Worksheet) mysheet.cells(1, 1).Value = "Drawing" mysheet.cells(1, 2).Value = "Sheet #" mysheet.cells(1, 3).Value = "Title" mysheet.cells(1, 4).Value = "Drafter" mysheet.cells(1, 5).Value = "Checker" mysheet.cells(1, 6).Value = "Plot Date" mysheet.cells(1, 7).Value = "Revision" mysheet.usedrange.cells.font.bold = True 11

13 Conclusion This course has demonstrated that there are many tools available to you outside of the AutoCAD object model. Please use the code presented here as a stepping-stone to improving the critical processes in your own firm. 12

The ABCs of VBA CP21-2. R. Robert Bell - MW Consulting Engineers

The ABCs of VBA CP21-2. R. Robert Bell - MW Consulting Engineers 11/29/2005-8:00 am - 11:30 am Room:Swan 7/8 (Swan) Walt Disney World Swan and Dolphin Resort Orlando, Florida R. Robert Bell - MW Consulting Engineers CP21-2 Do you want to customize AutoCAD using VBA