public static void Main()
{
Assembly SampleAssembly;
string str = "C:\\WINNT\\Microsoft.NET\\Framework\\v1.0.3705\\mscorlib.dll";
SampleAssembly = Assembly.LoadFrom(str);
Type[] t;
t = SampleAssembly.GetTypes();
foreach (Type x in t)
	{
	if (x.IsValueType == true) 
	     if (x.IsPrimitive == true)
		listBox1.Items.Add(x.FullName.ToString());
	}
}