你调用的对象是空的

Question

Hello am calling from a class to test my product however i keep getting this error: "Object reference not set to an instance of an object."

Testing:

global::OfficeSystem.Employees employees = new OfficeSystem.Employees();

employees.Delete(Convert.ToInt64("17")); <--- Primary Key
employees.GetEmployeeByOfficeID(Convert.ToInt64("6"));

What is the problem here?

Answer 1

It sounds like for what ever reason you are not instantiating your object. I suggest run you code in debug and add a watch on employees to make sure its not zero. Hope that helps.

Answer 2

This simply means you are using an object that is null . Accessing a member on null is never valid.

I'm not sure which line is causing the error. Is it the one that says "Primary Key"? If so, could employees be null ? It should be extremely trivial to find out using the debugger.

If needed, check for null before using the object to prevent this error.