Home > Articles > Programming > Windows Programming

  • Print
  • + Share This
Like this article? We recommend

Adding Versioning Information

As your program matures over time and you create newer versions, you’re probably going to need to handle different versions of files. If you have new features, you might want to write data to your file that supports those new features.

Generally speaking, when you create a new version of your program, you’ll want to be able to open any version of the data file up to the current version. For example, version 2.0 of your program should be able to open files saved with version 1.0 or 2.0. Version 3.0 should be able to open files saved with versions 1.0, 2.0, or 3.0.

As for dealing with future versions, that’s your call. For example, should version 1.0 be able to open files saved with version 3.0? Certainly 1.0 won’t be able to handle the data for the newer features, since 1.0 doesn’t have the newer features found in 3.0. You have several possibilities:

  • Refuse to open future versions, providing a friendly message stating that the file is from a newer version and asking that the user upgrade.
  • Open the file anyway, ignoring the newer features. When the file is resaved, the data from the newer features will be thrown out. (You would want to provide a warning message to the user before saving, however.)
  • Open the file anyway, save the data from the newer features aside, and rewrite them back to the file.

Of these, the first option is the easiest to implement, and the third is by far the most difficult to implement. Imagine that in version 3.0, you create a new class for a new feature, and save an instance of that class to the file. If you try to load the file with version 1.0 of the software (which doesn’t have the new class), the serialization library won’t be able to locate that class, and you’ll get an exception error. In a moment I’ll give you some tips how to work around this problem and make the third option work. But first let’s add the version information to the file.

To add a version number, simply write out the number before you write your data. You can use the Serialize method again:

formatter.Serialize(stream, ProgramVersion)

where ProgramVersion is a constant in your program for the version. (I used an Int32 for mine.) Then, when you read in the data, first read in the version so you know what file version you’re encountering. Do this before reading the rest of the data, since the version comes first in the stream:

Dim version As Int32
version = CType(readformatter.Deserialize(readstream), Int32)
If version > ProgramVersion Then
  ’ ... handle situation of future versions
End If

Next, you have to make a commitment to yourself that as you develop future versions of your program, you’ll continue with this same approach of writing the version number first. That way, version 3.0 will write the version number first, and if somebody uses version 1.0 to open a file saved with version 3.0, the first thing read will be the version number. Version 1.0 of the software will see that the file version is greater than the current version, and can deal with it in the "handle situation" remark I put in the preceding code.

Now let’s talk about how to handle the situation.

The first option is not to allow the user to open the file. That’s simply a matter of displaying a message and exiting the routine:

If version > ProgramVersion Then
  ’ ... handle situation of future versions
  MsgBox("This file was saved with a newer version. " & _
  "You can find information on our web site for upgrading at http://www...")
End If

For the second possibility, you can load the file anyway, but ignore the newer data. To accomplish that goal, however, you need to divide your data into version information. This may or may be feasible, depending on your particular program. One way to do it is to create new classes to hold the new features. Then you would write out the data broken up by version. Here’s some code that does this (for the version numbers, I’m using 1000 for 1.0.00 and 2000 for 2.0.00):

Dim formatter As New _
Dim stream As New FileStream("c:\temp\userdata.dat", _
  FileMode.Create, FileAccess.Write, FileShare.None)
formatter.Serialize(stream, 1000)
formatter.Serialize(stream, UserData1000) ’ 1.0.00 data
formatter.Serialize(stream, 2000)
formatter.Serialize(stream, UserData) ’ 2.0.00 data

The code in version 1.0 of the software would look the same, but with only the 1000 section, just as before. Version 3.0 of the software would write three sets. All versions, including version 1.0, would check the version before reading each block of data and only read up to their own data. Here’s the code that would accomplish this trick:

Dim done As Boolean = False
HaveFutureData = False
While Not done
    Dim version As Int32
    version = CType(readformatter.Deserialize(readstream), Int32)
    If version > ProgramVersion Then
      ’ Ignore the future data, but note that we have it.
      HaveFutureData = True
      readdata = CType(readformatter.Deserialize(readstream), ArrayList)
      ProcessData(readdata) ’ ... some function that processes the data
    End If
  Catch ex As Exception
    done = True
  End Try
End While

The variable HaveFutureData would be a member variable or perhaps a global variable. ProcessData would be a function you write that processes the incoming data. Thus, all the data that can be read would be read; data from future versions would be ignored.

Elsewhere in your code, when you save the data, you would want to check the value of HaveFutureData. If it’s True, you’ll want to warn the user that the file originally contained newer data and the newer data will be lost if you save. Also, you might provide a message when opening the file, warning the user that newer data will not be read in, and that rewriting will result in a loss of data.

As for the third possibility, where you read in the newer data anyway and save it aside—I’m not going to attempt to write that code here. In fact, I probably wouldn’t include such a feature, because it likely would be more work than it’s worth. Also, the code wouldn’t be fun. You’d have to open a BinaryReader stream on top of the FileStream you’re reading. If the version of data being read was higher than the current version, instead of calling Deserialize you would read in the block of data by using the BinaryReader’s read method. However, you’d need to figure out how long the data was, so you would know how much to read in. Then you’d have to save the raw data away in a structure, and write it back out later on when the file was saved, along with the version number. Personally, I don’t think it’s worth all that effort. You’re free to try it if you want, though.

  • + Share This
  • 🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020