Reflection Activator.CreateInstance() Saying Variables Are NULL

Question

string to = "user@example.com";
string from = "user@example.com";
string title = "Test";
string body = "Test Email";

Type t1 = Type.GetType("System.Net.Mail.MailMessage");
Object test = Activator.CreateInstance(t1, new object[] { to, from, title, body });

I'm trying to use reflection (don't ask why) for System.Net.Mail.
Right now when I run and compile, it says to, from, title, and body are NULL (System.ArgumentNullException: Value cannot be null.)

Why is this happening? and if I replace the variables with what they are defined with it works fine.

EDIT 1 Full Error

System.ArgumentNullException: Value cannot be null.

   at System.Activator.CreateInstance(Type type, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes)
   at System.Activator.CreateInstance(Type type, Object[] args)
   at mcclureski.Program.Main(String[] args) in c:\Users\JohnDoe\Documents\SharpDevelop Projects\Test\Program.cs:line 67

Answer 1

Activator.CreateInstance的第二个参数是params数组 ，因此不要实例化对象数组，只需将参数以正确的顺序放置以适合您的类型构造：

Object test = Activator.CreateInstance(t1, to, from, title, body);