Displaying the build date

Question

I currently have an app displaying the build number in its title window. That\'s well and good except it means nothing to most of the users, who want to know if they have t

Answer 1

For anyone that needs to get the compile time in Windows 8 / Windows Phone 8:

    public static async Task RetrieveLinkerTimestamp(Assembly assembly)
    {
        var pkg = Windows.ApplicationModel.Package.Current;
        if (null == pkg)
        {
            return null;
        }

        var assemblyFile = await pkg.InstalledLocation.GetFileAsync(assembly.ManifestModule.Name);
        if (null == assemblyFile)
        {
            return null;
        }

        using (var stream = await assemblyFile.OpenSequentialReadAsync())
        {
            using (var reader = new DataReader(stream))
            {
                const int PeHeaderOffset = 60;
                const int LinkerTimestampOffset = 8;

                //read first 2048 bytes from the assembly file.
                byte[] b = new byte[2048];
                await reader.LoadAsync((uint)b.Length);
                reader.ReadBytes(b);
                reader.DetachStream();

                //get the pe header offset
                int i = System.BitConverter.ToInt32(b, PeHeaderOffset);

                //read the linker timestamp from the PE header
                int secondsSince1970 = System.BitConverter.ToInt32(b, i + LinkerTimestampOffset);

                var dt = new DateTimeOffset(1970, 1, 1, 0, 0, 0, DateTimeOffset.Now.Offset) + DateTimeOffset.Now.Offset;
                return dt.AddSeconds(secondsSince1970);
            }
        }
    }

For anyone that needs to get the compile time in Windows Phone 7:

    public static async Task RetrieveLinkerTimestampAsync(Assembly assembly)
    {
        const int PeHeaderOffset = 60;
        const int LinkerTimestampOffset = 8;            
        byte[] b = new byte[2048];

        try
        {
            var rs = Application.GetResourceStream(new Uri(assembly.ManifestModule.Name, UriKind.Relative));
            using (var s = rs.Stream)
            {
                var asyncResult = s.BeginRead(b, 0, b.Length, null, null);
                int bytesRead = await Task.Factory.FromAsync(asyncResult, s.EndRead);
            }
        }
        catch (System.IO.IOException)
        {
            return null;
        }

        int i = System.BitConverter.ToInt32(b, PeHeaderOffset);
        int secondsSince1970 = System.BitConverter.ToInt32(b, i + LinkerTimestampOffset);
        var dt = new DateTimeOffset(1970, 1, 1, 0, 0, 0, DateTimeOffset.Now.Offset) + DateTimeOffset.Now.Offset;
        dt = dt.AddSeconds(secondsSince1970);
        return dt;
    }

NOTE: In all cases you're running in a sandbox, so you'll only be able to get the compile time of assemblies that you deploy with your app. (i.e. this won't work on anything in the GAC).