Specify build events (Visual Basic)

Build events in Visual Basic can be used to run scripts, macros, or other actions as a part of the compilation process. Pre-build events occur before compilation; post-build events occur after compilation.

How to specify pre-build and post-build events

To view or change build events for a Visual Basic .NET Core or .NET 5 and later project, right-click the project node, and choose Properties (or press Alt+Enter), then go to Compile > Events. Enter the desired command line. The working directory is the output directory.

For .NET Framework projects, follow these steps:

1. With a project selected in Solution Explorer, on the Project menu, click Properties.

2. Click the Compile tab.

3. Click the Build Events button to open the Build Events dialog box.

4. Enter the command-line arguments for your pre-build or post-build action, and then click OK.

Note

Add a call statement before all post-build commands that run .bat files. For example, call C:\MyFile.bat or call C:\MyFile.bat call C:\MyFile2.bat.

Note

If your pre-build or post-build event does not complete successfully, you can terminate the build by having your event action exit with a code other than zero (0), which indicates a successful action.

Example: How to change manifest information using a post-build event

The following procedure shows how to set the minimum operating system version in the application manifest using an .exe command called from a post-build event (the .exe.manifest file in the project directory). The minimum operating system version is a four-part number such as 4.10.0.0. To do this, the command will change the <dependentOS> section of the manifest:

<dependentOS>
   <osVersionInfo>
      <os majorVersion="4" minorVersion="10" buildNumber="0" servicePackMajor="0" />
   </osVersionInfo>
</dependentOS>

To create an .exe command to change the application manifest

1. Create a console application for the command. From the File menu, click New, and then click Project.

2. In the New Project dialog box, in the Visual Basic node, select Windows and then the Console Application template. Name the project ChangeOSVersionVB.

3. In Module1.vb, add the following line to the other Imports statements at the top of the file:

   Imports System.Xml
   

4. Add the following code in Sub Main:

   Sub Main()
      Dim applicationManifestPath As String
      applicationManifestPath = My.Application.CommandLineArgs(0)
      Console.WriteLine("Application Manifest Path: " & applicationManifestPath.ToString)
   
      'Get version name
      Dim osVersion As Version
      If My.Application.CommandLineArgs.Count >= 2 Then
         osVersion = New Version(My.Application.CommandLineArgs(1).ToString)
      Else
         Throw New ArgumentException("OS Version not specified.")
      End If
      Console.WriteLine("Desired OS Version: " & osVersion.ToString())
   
      Dim document As XmlDocument
      Dim namespaceManager As XmlNamespaceManager
      namespaceManager = New XmlNamespaceManager(New NameTable())
      With namespaceManager
         .AddNamespace("asmv1", "urn:schemas-microsoft-com:asm.v1")
         .AddNamespace("asmv2", "urn:schemas-microsoft-com:asm.v2")
      End With
   
      document = New XmlDocument()
      document.Load(applicationManifestPath)
   
      Dim baseXPath As String
      baseXPath = "/asmv1:assembly/asmv2:dependency/asmv2:dependentOS/asmv2:osVersionInfo/asmv2:os"
   
      'Change minimum required OS Version.
      Dim node As XmlNode
      node = document.SelectSingleNode(baseXPath, namespaceManager)
      node.Attributes("majorVersion").Value = osVersion.Major.ToString()
      node.Attributes("minorVersion").Value = osVersion.Minor.ToString()
      node.Attributes("buildNumber").Value = osVersion.Build.ToString()
      node.Attributes("servicePackMajor").Value = osVersion.Revision.ToString()
   
      document.Save(applicationManifestPath)
   End Sub
   

   The command takes two arguments. The first argument is the path to the application manifest (that is, the folder in which the build process creates the manifest, typically <ProjectName>.publish). The second argument is the new operating system version.

5. On the Build menu, click Build Solution.

6. Copy the .exe file to a directory such as C:\TEMP\ChangeOSVersionVB.exe.

   Next, invoke this command in a post-build event to change the application manifest.

To invoke a post-build event to change the application manifest

1. Create a Windows application for the project to be published. From the File menu, click New, and then click Project.

2. In the New Project dialog box, in the Visual Basic node, select Windows Desktop and then the Windows Forms App template. Name the project VBWinApp.

3. With the project selected in Solution Explorer, on the Project menu, click Properties.

4. In the Project Designer, go to the Publish page and set Publishing location to C:\TEMP.

5. Publish the project by clicking Publish Now.

   The manifest file will be built and put in C:\TEMP\VBWinApp_1_0_0_0\VBWinApp.exe.manifest. To view the manifest, right-click the file and click Open with, then click Select the program from a list, and then click Notepad.

   Search in the file for the <osVersionInfo> element. For example, the version might be:

   <os majorVersion="4" minorVersion="10" buildNumber="0" servicePackMajor="0" />
   

6. In the Project Designer, go to the Compile tab and click the Build Events button to open the Build Events dialog box.

7. In the Post-build Event Command Line box, enter the following command:

   C:\TEMP\ChangeOSVersionVB.exe "$(TargetPath).manifest" 5.1.2600.0

   When you build the project, this command will change the minimum operating system version in the application manifest to 5.1.2600.0.

   The $(TargetPath) macro expresses the full path for the executable being created. Therefore, $(TargetPath).manifest will specify the application manifest created in the bin directory. Publishing will copy this manifest to the publishing location that you set earlier.

8. Publish the project again. Go to the Publish page and click Publish Now.

   View the manifest again. To view the manifest, go to the publish directory, right-click the file and click Open with and then Select the program from a list, and then click Notepad.

   The version should now read:

   <os majorVersion="5" minorVersion="1" buildNumber="2600" servicePackMajor="0" />
   

Related content

• Compile page, Project Designer (Visual Basic)
• Publish page, Project Designer
• Pre-build event/Post-build event command line dialog box
• How to: Specify build events (C#)