When I try to create a request by a webservice and get a response out of it, I get this lovely warning message : "Object reference not set to an instance of an object.", I always see an animation of "little hearts" flying around me. I feel luv, I feel happiness... Of course these words are irrelevant to explain my anger towards this snappish warning that I face with in my daily programming life .o_O.
The reason for this error is that you are trying to create a whole car without creating first its components such as wheel, glasss, engine and etc. Ok, let me put this kind of examples away and give a nice example for hard-core coders [as if a hard-coder gets such an error :-) ].
Here how it is, you have a webservice "StudentComponent" that has SearchStudentReqıest service that lets you enter some parameters such as name, surname, courses. Now when you create a request object in your .cs file like given below;
Student student = new Student();
student.name = "Mike";
student.surname = "Givemefive";
student.courses = new stıdent.courses();
stıdent.courses = "Math"; *
student.courses= 'Scinece"; *
Here the weird thing shows up if you implement your functionality as given above. The lines marked with "*" cause this problem. While dealing with SOA, I am not sure why, you have to initialize each object of the array like
student.courses = new StudentComponent.tcourse();
student.course = new StudentComponent.tcourse();
After doing this, you will have no problem at all.
Note: tcourses() function is assumed to be given in the webservice.
If you can explain it better with your experience , please be my guest and leave a comment ;)