Let’s say you want to add an AssemblyVersionAttribute to a web project. The usual practice is to add a file to the project with the name AssemblyInfo.cs. The AssemblyInfo.cs file will live in the App_Code folder, because that is the only location the new web project model will allow stand-alone code files. The contents might look like:
using System.Reflection;
[assembly: AssemblyVersion("2.1.1.2")]
Next, a web form to display the version number:
<%@ Page Language="C#" %>
<%@ Import Namespace="System.Reflection" %>
<script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
Assembly assembly = Assembly.GetExecutingAssembly();
string version = assembly.GetName().Version.ToString();
versionLabel.Text = version;
}
</script>
Version:
<asp:Label runat="server" ID="versionLabel" />
The above web form will happily display the version number as 0.0.0.0 because App_Code compiles into a different assembly than the web form. The App_Code assembly will have the version number we need. The ASP.NET compiler doesn’t assign a version number to the dynamically generated assemblies for web forms. This is true in 1.1, too, it’s just that we usually asked for the version number from a code-behind file, and all the code-behind files compiled together into a single assembly.
There are a couple approaches to getting the version number from the AssemblyVersionAttribute in App_Code. One approach would be to substitute the following in our earlier code:
Assembly assembly = Assembly.Load("App_Code");
string version = assembly.GetName().Version.ToString();
I think an even better approach is to use the Web Deployment Project, which can merge all assemblies into a single assembly, and copy assembly level attributes over, too. If you are using the newer Web Application Project model, then any code in a code-behind file will be able to see the version in an AssemblyVersion source file.