Getting the date of a .NET assembly

Question

How can I retrieve the Created date from the current .NET assembly?

I'd like to add some realy simple functionality where my app stops working one week after the build date of the main assembly. I already wrote the code that kills my app after a given date. I just need to programmatically retrieve the creation date from the assembly.

Answer 1

This should work:

var entryAssembly = Assembly.GetEntryAssembly();
var fileInfo = new FileInfo(entryAssembly.Location);
var buildDate = fileInfo.LastWriteTime;

Answer 2

What's wrong with:

System.IO.File.GetLastWriteTime(Assembly.GetExecutingAssembly().Location);

Answer 3

I don't think the assembly itself contains it's creation date. I suspect the closest you can get is the creation date of the assembly file itself:

File.GetCreationTime(Assembly.GetExecutingAssembly().Location)

should do the trick.

Answer 4

The best way to do this would be with a custom attribute that you set on the PreBuild of your assembly.

And then use the standard reflection to get the attribute you created.

But out of curiosity, why kill the app after the BUILD date?

Answer 5

Maybe this post on coding horror may help

Answer 6

The following is based on: http://www.codinghorror.com/blog/2005/04/determining-build-date-the-hard-way.html

public static class ApplicationInformation
{
    /// <summary>
    /// Gets the executing assembly.
    /// </summary>
    /// <value>The executing assembly.</value>
    public static System.Reflection.Assembly ExecutingAssembly
    {
        get { return executingAssembly ?? (executingAssembly = System.Reflection.Assembly.GetExecutingAssembly()); }
    }
    private static System.Reflection.Assembly executingAssembly;

    /// <summary>
    /// Gets the executing assembly version.
    /// </summary>
    /// <value>The executing assembly version.</value>
    public static System.Version ExecutingAssemblyVersion
    {
        get { return executingAssemblyVersion ?? (executingAssemblyVersion = ExecutingAssembly.GetName().Version); }
    }
    private static System.Version executingAssemblyVersion;

    /// <summary>
    /// Gets the compile date of the currently executing assembly.
    /// </summary>
    /// <value>The compile date.</value>
    public static System.DateTime CompileDate
    {
        get
        {
            if (!compileDate.HasValue)
                compileDate = RetrieveLinkerTimestamp(ExecutingAssembly.Location);
            return compileDate ?? new System.DateTime();
        }
    }
    private static System.DateTime? compileDate;

    /// <summary>
    /// Retrieves the linker timestamp.
    /// </summary>
    /// <param name="filePath">The file path.</param>
    /// <returns></returns>
    /// <remarks>http://www.codinghorror.com/blog/2005/04/determining-build-date-the-hard-way.html&lt;/remarks&gt;
    private static System.DateTime RetrieveLinkerTimestamp(string filePath)
    {
        const int peHeaderOffset = 60;
        const int linkerTimestampOffset = 8;
        var b = new byte[2048];
        System.IO.FileStream s = null;
        try
        {
            s = new System.IO.FileStream(filePath, System.IO.FileMode.Open, System.IO.FileAccess.Read);
            s.Read(b, 0, 2048);
        }
        finally
        {
            if(s != null)
                s.Close();
        }
        var dt = new System.DateTime(1970, 1, 1, 0, 0, 0).AddSeconds(System.BitConverter.ToInt32(b, System.BitConverter.ToInt32(b, peHeaderOffset) + linkerTimestampOffset));
        return dt.AddHours(System.TimeZone.CurrentTimeZone.GetUtcOffset(dt).Hours);
    }
}