If you want to get 4 return value from function, you have to declare MWArray[] with 4 parameters and Create an Object like this,
In C#:
MWArray[] Result = new MWArray[4];
MPC myMpcObj = new MPC();
Result = myMpcObj.Function_Apc(4,Inputlist);
Here 4 means number of output Now you can get 4 Output Return Values.