How do I programmatically get the GUID of an application in .NET 2.0

I need to access the assembly of my project in C# .NET 2.0.

I can see the GUID in the 'Assembly Information' dialog in under project properties, and at the moment I have just copied it to a const in the code. The GUID will never change, so this is not that bad of a solution, but it would be nice to access it directly. Is there a way to do this?

Solution 1:

Try the following code. The value you are looking for is stored on a GuidAttribute instance attached to the Assembly

using System.Runtime.InteropServices;

static void Main(string[] args)
{
    var assembly = typeof(Program).Assembly;
    var attribute = (GuidAttribute)assembly.GetCustomAttributes(typeof(GuidAttribute),true)[0];
    var id = attribute.Value;
    Console.WriteLine(id);
}

Solution 2:

Another way is to use Marshal.GetTypeLibGuidForAssembly.

According to MSDN:

When assemblies are exported to type libraries, the type library is assigned a LIBID. You can set the LIBID explicitly by applying the System.Runtime.InteropServices.GuidAttribute at the assembly level, or it can be generated automatically. The Tlbimp.exe (Type Library Importer) tool calculates a LIBID value based on the identity of the assembly. GetTypeLibGuid returns the LIBID that is associated with the GuidAttribute, if the attribute is applied. Otherwise, GetTypeLibGuidForAssembly returns the calculated value. Alternatively, you can use the GetTypeLibGuid method to extract the actual LIBID from an existing type library.

Solution 3:

Or, just as easy:

string assyGuid = Assembly.GetExecutingAssembly().GetCustomAttribute<GuidAttribute>().Value.ToUpper();

It works for me...

Solution 4:

You should be able to read the GUID attribute of the assembly via reflection. This will get the GUID for the current assembly

    Assembly asm = Assembly.GetExecutingAssembly();
    object[] attribs = asm.GetCustomAttributes(typeof(GuidAttribute), true);
    var guidAttr = (GuidAttribute) attribs[0];
    Console.WriteLine(guidAttr.Value);

You can replace the GuidAttribute with other attributes as well, if you want to read things like AssemblyTitle, AssemblyVersion, etc.

You can also load another assembly (Assembly.LoadFrom and all) instead of getting the current assembly - if you need to read these attributes of external assemblies (for example, when loading a plugin).

Solution 5:

For an out-of-the-box working example, this is what I ended up using based on the previous answers.

using System.Reflection;
using System.Runtime.InteropServices;

label1.Text = "GUID: " + ((GuidAttribute)Attribute.GetCustomAttribute(Assembly.GetExecutingAssembly(), typeof(GuidAttribute), false)).Value.ToUpper();

Alternatively, this way allows you to use it from a static class:

    /// <summary>
    /// public GUID property for use in static class </summary>
    /// <returns>
    /// Returns the application GUID or "" if unable to get it. </returns>
    static public string AssemblyGuid
    {
        get
        {
            object[] attributes = Assembly.GetEntryAssembly().GetCustomAttributes(typeof(GuidAttribute), false);
            if (attributes.Length == 0) { return String.Empty; }
            return ((System.Runtime.InteropServices.GuidAttribute)attributes[0]).Value.ToUpper();
        }
    }