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Entries Tagged ‘Verify’

How To Access and Modify SQL Server BLOB Data by Using the ADO Stream Object

Symptoms
The Stream object introduced in ActiveX Data Objects (ADO) 2.5 can be used to greatly simplify the code that needs to be written to access and modify Binary Large Object (BLOB) data in a SQL Server Database. The previous versions of ADO [ 2.0, 2.1, and 2.1 SP2 ] required careful usage of the GetChunk and AppendChunk methods of the Field Object to read and write BLOB data in fixed-size chunks from and to a BLOB column. An alternative to this method now exists with the advent of ADO 2.5. This article includes code samples that demonstrate how the Stream object can be used to program the following common tasks: Save the data stored in a SQL Server Image column to a file on the hard disk.Move the contents of a .gif file to an Image column in a SQL Server table.
Resolution
The following code samples are based on the data stored in the pub_info table in the SQL Server 7.0 pubs sample database. You need to modify the ADO connection string to point to your SQL Server installation. Example 1 : Saving the Data in a SQL Server Image Column to a File on the Hard Disk The code in this example opens a recordset on the pub_info table in the pubs database and saves the binary image data stored in the logo column of the first record to a file on the hard disk, as follows: Open a new Standard EXE Visual Basic project.On the Project menu, click to select References, and then set a reference to the Microsoft ActiveX Data Objects 2.5 Object Library.Place a CommandButton control on Form1.Make the following declarations in the form’s General declarations section:

Dim cn As ADODB.ConnectionDim rs As ADODB.RecordsetDim mstream As ADODB.Stream Cut and paste the following code into the Click event of the CommandButton that you added to the form:

Set cn = New ADODB.Connectioncn.Open “Provider=SQLOLEDB;data Source=<name of your SQL Server>;Initial Catalog=pubs;User Id=<Your Userid>;Password=<Your Password>”Set rs = New ADODB.Recordsetrs.Open “Select * from pub_info”, cn, adOpenKeyset, adLockOptimisticSet mstream = New ADODB.Streammstream.Type = adTypeBinarymstream.Openmstream.Write rs.Fields(“logo”).Valuemstream.SaveToFile “c:\publogo.gif”, adSaveCreateOverWriters.Closecn.Close Save and run the Visual Basic project.Click the CommandButton to save the binary data in the logo column of the first record to the file c:\publogo.gid. Look for this file in Windows Explorer and open it to view the saved image.
The code in this example declares an ADODB Stream object and sets its Type property to adTypeBinary to reflect that this object will be used to work with Binary data. Following this, the binary data stored in the logo column of the first record in the pub_info table is written out to the Stream object by calling its Write method. The Stream object now contains the binary data that is saved to the file by calling its SaveToFile method and passing in the path to the file. The adSaveCreateOverWrite constant passed in as the second parameter causes the SaveToFile method to overwrite the specified file if it already exists.Example 2 : Transfer the Image Stored in a .gif File to an Image Column in a SQL Server Table The code in this example saves an image stored in a .gif file to the logo column in the first record of the pub_info table by overwriting its current contents, as follows: Open a new Standard EXE Visual Basic project.On the Project menu, click to select References, and then set a reference to the Microsoft ActiveX Data Objects 2.5 Object Library.Place a CommandButton on Form1. Make the following declarations in the form’s General declarations section:

Dim cn As ADODB.ConnectionDim rs As ADODB.RecordsetDim mstream As ADODB.Stream Cut and paste the following code in the Click event of the CommandButton that you added to the form:

Set cn = New ADODB.Connectioncn.Open “Provider=SQLOLEDB;data Source=<name of your SQL Server>;Initial Catalog=pubs;User Id=<Your Userid>;Password=<Your Password>”Set rs = New ADODB.Recordsetrs.Open “Select * from pub_info”, cn, adOpenKeyset, adLockOptimisticSet mstream = New ADODB.Streammstream.Type = adTypeBinarymstream.Openmstream.LoadFromFile “<path to .gif file>”rs.Fields(“logo”).Value = mstream.Readrs.Updaters.Closecn.Close Save and run the Visual Basic project.Click on the CommandButton to run the code to stream the contents of the .gif file to the ADO Stream object, and save the data in the Stream to the logo column in the first record of the recordset.Verify that the image in the logo column has been modified by using the code in Example 1.

INFO: Troubleshooting Error 429 When Automating Office Applications

Symptoms
When you use the New operator or CreateObject function in Microsoft Visual Basic to create an instance of a Microsoft Office application, you may get the following error message:

Run-time error ‘429′: ActiveX component can’t create objectThis error occurs when the requested Automation object could not be created by COM, and is therefore unavailable to Visual Basic. The error is typically seen on certain computers but not others.
This article provides some troubleshooting tips to help you diagnose and resolve common problems that are known to cause this error.
Resolution
Unlike some errors in Visual Basic, there is no one cause to an error 429. The problem happens because of an error in the application or system configuration, or a missing or damaged component. Finding the exact cause is a matter of eliminating possibilities. If you encounter this error on a client computer, there are a number of things you will need to check to isolate and resolve the error.
The items later give you some practical suggestions for troubleshooting this error when you work with Office Applications. Some of this information may also apply to non-Office COM servers as well, but this article assumes you are trying to automate Microsoft Office.
Checking the CodeThe first place to begin looking for the problem is in the code. Before you can troubleshoot the error, you need to know where the error occurs. Try to narrow it down to a single line of code.
When you find the code that is failing, try to do the following:
Make sure the code uses explicit object creation. Any problem is easier to spot and identify if the problem is narrowed to a single action. For example, do not do the following:

Application.Documents.Add ‘DON’T USE THIS!!
or:

Dim oWordApp As New Word.Application ‘DON’T USE THIS!!’… some other codeoWordApp.Documents.Add Both of these methods use implicit object creation. Microsoft Word is not started until the variable is called at least once. Since the variable could be called in different parts of the program, this could make the problem hard to localize. Also, it is not clear whether the problem is with creating the Application object or the Document object.
Instead, make explicit calls to create each object separately:

Dim oWordApp As Word.ApplicationDim oDoc As Word.DocumentSet oWordApp = CreateObject(“Word.Application”)’… some other codeSet oDoc = oWordApp.Documents.Add This makes the problem easier to isolate and makes the code more readable.When creating an instance of an Microsoft Office application, use CreateObject instead of New. CreateObject more closely maps to the creation process used by most Visual C++ clients, and allows for possible changes in the server’s CLSID between versions. CreateObject can be used with both early-bound and late-bound objects.Verify that the ProgID string passed to CreateObject is correct and that it is version independent (that is, use “Excel.Application” rather than “Excel.Application.8″). It could be that the system that is failing has an older or newer version of Microsoft Office than the version you specified in the ProgID.To aid in debugging applications that cannot be run in the IDE, use the Erl command to report the line number of the line that fails. For example, the following code will tell you which Automation object cannot be created (Word or Excel):

Dim oWord As Word.ApplicationDim oExcel As Excel.ApplicationOn Error Goto err_handler1: Set oWord = CreateObject(“Word.Application”)2: Set oExcel = CreateObject(“Excel.Application”)’ … some other codeerr_handler:MsgBox “The code failed at line ” & Erl, vbCritical Use a combination of message boxes and line numbers to track down the error.Try using late binding (that is, Dim oWordApp As Object). Early bound objects require their custom interfaces to be marshaled across process boundaries. If there is a problem marshaling a custom interface during CreateObject or New, you will get an error 429. A late bound object uses a system-defined interface (IDispatch) that does not require a custom proxy in order to be marshaled. Try using a late bound object to see if this makes a difference.
If the problem occurs only when the object is early-bound, the problem is with the server application, and can typically be corrected by reinstalling the application (see later).If you are automating from ASP or an MTS component, use CreateObject instead of Server.CreateObject(). Using Server.CreateObject will instantiate the Office application under the identity of an MTS package which is known to cause problems with Microsoft Office.
Checking the Automation ServerThe most common reasons for an error with CreateObject or New are problems with the server application itself. Typically, these problems are with the configuration or setup of the application. Here are some items to check:
Verify the Microsoft Office application you want to Automate is installed on the local computer, and make sure that you can start the application from the Start and then Run dialog box. If the program cannot be started manually, it will not work through automation.Re-register the application by typing the path to the server in the Start and then Run dialog box, and then append /RegServer to the end of the line. Press OK. This should silently run the application and re-register it as a COM server. If the problem is with a missing registry key, this will typically correct it.Check the LocalServer32 key under the CLSID for the application you want to Automate. Make sure it points to the correct location for the application, and make sure the path name is in a short path (DOS 8.3) format. While it is not a requirement that a server be registered using a short path name, long path names that include embedded spaces have been known to cause problems on some systems (see later).
To check the path key stored for the server, start the Windows Registry Editor by typing regedit in the Start and then Run dialog box. Navigate to the HKEY_CLASSES_ROOT\Clsid key. Under this key you will find the CLSIDs for the registered automation servers on the system. Using the values later, find the key that represents the Office application you want to Automate and check its LocalServer32 key for the path.

+========================+=========================================+| Office Server| CLSID Key|+========================+=========================================+| Access.Application| {73A4C9C1-D68D-11D0-98BF-00A0C90DC8D9}|+————————+—————————————–+| Excel.Application| {00024500-0000-0000-C000-000000000046}|+————————+—————————————–+| FrontPage.Application| {04DF1015-7007-11D1-83BC-006097ABE675}|+————————+—————————————–+| Outlook.Application| {0006F03A-0000-0000-C000-000000000046}|+————————+—————————————–+| PowerPoint.Application | {91493441-5A91-11CF-8700-00AA0060263B}|+————————+—————————————–+| Word.Application| {000209FF-0000-0000-C000-000000000046}|+————————+—————————————–+ Does the path match the actual location of the file? Be aware that short path names can give you the impression that a path is correct when it may not be. For example, both Microsoft Office and Microsoft Internet Explorer (if installed in their default locations) will have a short path similar to “C:\PROGRA~1\MICROS~X\” where X is some number. It is not immediately obvious that you are looking at from a short path name.
You can test that the path is indeed correct by copying the value from the registry and pasting it into the Start and then Run dialog box (remove the /Automation switch before running the application). Does the application start when you select OK? If yes, then the server is registered correctly. If not, you should replace the value of the LocalServer32 key with the correct path (use a short path name if possible).Problems have been known to occur when automating Word or Excel if either the Normal.dot template (Word) or the Excel.xlb resource file (Excel) has become corrupt. To test if a corruption has occurred, search the local hard drives to find all instances of Normal.dot or *.xlb. (Please note that if you are running Windows 2000, Windows NT, or Windows 95/98 with profiles enabled, you may find multiple copies of these files, one for each user profile on the system.) Temporarily rename the Normal.dot file(s) or the *.xlb file(s), and re-run your Automation test (Word and Excel will create these files if they cannot find them). Does the code now work? If yes, then the files you renamed should be deleted since they are corrupt. If not, you should rename them back to their original names so any custom settings saved in these files won’t be lost.If you are on a Windows NT, Windows 2000, Windows XP, or Windows Server 2003 system, run the application under the Administrator account. Office servers require read/write access to the registry and disk drive, and may not properly load if your current security settings deny this privilege.
Checking the SystemSystem configuration can also cause problems with the creation of out-of-process COM servers. The following are some things to check on systems where the error occurs: Does the problem happen with any out-of-process server? If you have an application that just uses a particular COM server (for example, Word), you’ll want to test a different out-of-process server to make sure the problem is not with COM layer itself. If no out-of-process COM server can be created on that system, then a reinstallation of the OLE system files (see below) or a reinstallation of the operating system will be required to resolve the issue.Check the version numbers for the OLE system files that manage Automation. These files are typically installed as a set, and should match build numbers. An improperly configured setup utility can mistakenly install the files separately, causing them to become mismatched. To avoid problems with Automation, you should check the files to make sure the files match builds.
You will find the Automation files in the Windows\System or Winnt\System32 directory. The following is the list of files to check:

+—————+————-+—————-+| File Name|Version| Date Modified|+—————+————-+—————-+| Asycfilt.dll|2.40.4275| March 08, 1999 || Oleaut32.dll|2.40.4275| March 08, 1999 || Olepro32.dll|5.0.4275| March 08, 1999 || Stdole2.tlb|2.40.4275| March 08, 1999 |+—————+————-+—————-+ Check the file version by right-clicking on the file in Explorer and selecting Properties from the popup menu. The values most important are the last four digits of the file version (the build number) and the date last modified. You want to make sure these values are the same for all the Automation files.
Please note that the version numbers and dates given above are for example purposes only. Your values may differ. The important thing is that these values match each other, rather than this table.
If the files don’t match build numbers or modified dates, you can download a self-extracting utility that will update your Automation files. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
290887?(http://support.microsoft.com/kb/290887/) VBRun60sp6.exe installs Visual Basic 6.0 SP6 run-time filesWindows NT 4.0 has a known problem with starting Automation servers that live in a folder that contains an embedded space in the name, and/or resembles another folder whose first 8 characters are identical. For example, a server living in C:\Program Files\SomeFolder may fail to start during a call to CreateObject if there is another folder on the system called C:\Program Stuff\SomeFolder. For more information, see the following Knowledge Base article:For additional information about this problem and steps to workaround it, click the article number below to view the article in the Microsoft Knowledge Base:
185126?(http://support.microsoft.com/kb/185126/EN-US/) BUG: COM/OLE Server Fails to Start on Windows NT 4.0
Reinstalling Microsoft OfficeIf none of the preceding steps helps to resolve the problem, consider uninstalling and reinstalling Microsoft Office. Microsoft recommends that you uninstall the existing version first, and then reinstall from the original installation disks.
For a complete list of the items to be removed, please see the following Knowledge Base articles:
219423?(http://support.microsoft.com/kb/219423/EN-US/) OFF2000: How to Completely Remove Microsoft Office 2000
158658?(http://support.microsoft.com/kb/158658/EN-US/) OFF97: How to Completely Remove Microsoft Office 97

How To Access and Modify SQL Server BLOB Data by Using the ADO Stream Object

Symptoms
The Stream object introduced in ActiveX Data Objects (ADO) 2.5 can be used to greatly simplify the code that needs to be written to access and modify Binary Large Object (BLOB) data in a SQL Server Database. The previous versions of ADO [ 2.0, 2.1, and 2.1 SP2 ] required careful usage of the GetChunk and AppendChunk methods of the Field Object to read and write BLOB data in fixed-size chunks from and to a BLOB column. An alternative to this method now exists with the advent of ADO 2.5. This article includes code samples that demonstrate how the Stream object can be used to program the following common tasks: Save the data stored in a SQL Server Image column to a file on the hard disk.Move the contents of a .gif file to an Image column in a SQL Server table.
Resolution
The following code samples are based on the data stored in the pub_info table in the SQL Server 7.0 pubs sample database. You need to modify the ADO connection string to point to your SQL Server installation. Example 1 : Saving the Data in a SQL Server Image Column to a File on the Hard Disk The code in this example opens a recordset on the pub_info table in the pubs database and saves the binary image data stored in the logo column of the first record to a file on the hard disk, as follows: Open a new Standard EXE Visual Basic project.On the Project menu, click to select References, and then set a reference to the Microsoft ActiveX Data Objects 2.5 Object Library.Place a CommandButton control on Form1.Make the following declarations in the form’s General declarations section:

Dim cn As ADODB.ConnectionDim rs As ADODB.RecordsetDim mstream As ADODB.Stream Cut and paste the following code into the Click event of the CommandButton that you added to the form:

Set cn = New ADODB.Connectioncn.Open “Provider=SQLOLEDB;data Source=<name of your SQL Server>;Initial Catalog=pubs;User Id=<Your Userid>;Password=<Your Password>”Set rs = New ADODB.Recordsetrs.Open “Select * from pub_info”, cn, adOpenKeyset, adLockOptimisticSet mstream = New ADODB.Streammstream.Type = adTypeBinarymstream.Openmstream.Write rs.Fields(“logo”).Valuemstream.SaveToFile “c:\publogo.gif”, adSaveCreateOverWriters.Closecn.Close Save and run the Visual Basic project.Click the CommandButton to save the binary data in the logo column of the first record to the file c:\publogo.gid. Look for this file in Windows Explorer and open it to view the saved image.
The code in this example declares an ADODB Stream object and sets its Type property to adTypeBinary to reflect that this object will be used to work with Binary data. Following this, the binary data stored in the logo column of the first record in the pub_info table is written out to the Stream object by calling its Write method. The Stream object now contains the binary data that is saved to the file by calling its SaveToFile method and passing in the path to the file. The adSaveCreateOverWrite constant passed in as the second parameter causes the SaveToFile method to overwrite the specified file if it already exists.Example 2 : Transfer the Image Stored in a .gif File to an Image Column in a SQL Server Table The code in this example saves an image stored in a .gif file to the logo column in the first record of the pub_info table by overwriting its current contents, as follows: Open a new Standard EXE Visual Basic project.On the Project menu, click to select References, and then set a reference to the Microsoft ActiveX Data Objects 2.5 Object Library.Place a CommandButton on Form1. Make the following declarations in the form’s General declarations section:

Dim cn As ADODB.ConnectionDim rs As ADODB.RecordsetDim mstream As ADODB.Stream Cut and paste the following code in the Click event of the CommandButton that you added to the form:

Set cn = New ADODB.Connectioncn.Open “Provider=SQLOLEDB;data Source=<name of your SQL Server>;Initial Catalog=pubs;User Id=<Your Userid>;Password=<Your Password>”Set rs = New ADODB.Recordsetrs.Open “Select * from pub_info”, cn, adOpenKeyset, adLockOptimisticSet mstream = New ADODB.Streammstream.Type = adTypeBinarymstream.Openmstream.LoadFromFile “<path to .gif file>”rs.Fields(“logo”).Value = mstream.Readrs.Updaters.Closecn.Close Save and run the Visual Basic project.Click on the CommandButton to run the code to stream the contents of the .gif file to the ADO Stream object, and save the data in the Stream to the logo column in the first record of the recordset.Verify that the image in the logo column has been modified by using the code in Example 1.