SendMessage , how can i send two parameter

Actually, the SendMessage function takes 1 argument, but that argument could be an array. So just make a temporary object[] array, fill it with all your values, and fire it away.

 string a = "abc";
 string b = "def";
 string c = "ghi";
 string d = "jkl";
 
 private void Start()
 {
     object[] tempStorage = new object[4];
     tempStorage[0] = a;
     tempStorage[1] = b;
     tempStorage[2] = c;
     tempStorage[3] = d;
 
     SendMessage("MessageRecieved", tempStorage);
 }

Sorry to answer an already answered question and it being so delayed, but you can send multiple parameters with a sendmessage in a sense. The way i have been doing it is make the function you need take a Vector2 argument in your case since you have 2 floats and then simply call Sendmessage and pass it a new vector2 with the floats u want to pass.

Example in C#:

Reciever:

Sender:

Again sorry for late answer just trying to help out =P

Note: u can also do this with vector3 to send 3 parameters.