6.18 (Inherit + (four-class access modifier + assembly + static method) outline

Inherited:

First, what is inheritance

Concept: The father has something, and allows inheritance , all children will have

A parent class can have more than one child class

A subclass can have only one parent class

Ii. conversion between father and son

A subclass can be converted to a parent class, which can only be converted to a previous subclass

Sub-classes cannot be converted between each other

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1. Access modifier:

One permission limit for cross-class access

Public: The reference namespace is free to access, with the highest access rights.

Private: It can only be accessed in the class and structure in which it is declared, with the lowest access rights.

Internal: Internal, all classes in the same assembly can be accessed, and assemblies are namespaces. (Less than a detailed example of the current use)

(When not in the same namespace: Import namespaces can work correctly; method: Instantiate + Right-click class name → Parse →using Class)

Protected: Protected, can only be accessed in his own and in his own subclasses. (Less than a detailed example of the current use)

2. Namespace = assembly

Group name for a group of classes

3. Static method

Static methods and properties are used to define them;

Non-static methods need to instantiate the object and then invoke it with the object;

Random r = new random ();//instantiation

R.next (); --How to use non-static methods

Static methods, you can instantiate the object , you can not instantiate the object, directly using the class can be point out of use;

Console.Write (); --How to use static methods

(directly with the name of the class.)

6.18 (Inherit + (four-class access modifier + assembly + static method) outline