public void Reflection()
{
var db = new TrackerDataContext { Log = Console.Out };
IQueryable source = db.Task.Where(t => t.LastModifiedBy == "*****@*****.**").OrderBy(t => t.CreatedId);
// can be static
Type queryableType = typeof(Queryable);
// can be static
MethodInfo countMethod = (from m in queryableType.GetMethods(BindingFlags.Static | BindingFlags.Public)
where m.Name == "Count"
&& m.IsGenericMethod
&& m.GetParameters().Length == 1
select m).FirstOrDefault();
Assert.IsNotNull(countMethod);
var genericMethod = countMethod.MakeGenericMethod(new[] { source.ElementType });
var expression = Expression.Call(null, genericMethod, source.Expression);
Assert.IsNotNull(expression);
Type dataContextType = db.GetType();
PropertyInfo providerProperty = dataContextType.GetProperty("Provider", BindingFlags.Instance | BindingFlags.NonPublic);
object provider = providerProperty.GetValue(db, null);
Type providerType = provider.GetType().GetInterface("IProvider");
MethodInfo getCommandMethod = providerType.GetMethod("GetCommand", BindingFlags.Instance | BindingFlags.Public);
object commandObject = getCommandMethod.Invoke(provider, new object[] { expression });
Assert.IsNotNull(commandObject);
}
