Definition of C class and method

C# Definition of classes and methods

The definition of a class

grammar ： Class access modifier    Modifier  class（ keyword ） Class name { Class members }

example ：

explain ：

Class access modifier ： Used to set access restrictions on classes .

Respectively public Indicates that the class can be accessed in any project 、internal or Omit not to write Indicates that the class can only be accessed in the current project .

Modifier ： A modifier is a description of the characteristics of a class itself .

abstract It means Abstract , Classes that use its modifier cannot be instantiated ;

sealed The decorated class is the sealed class , uninheritable ;

static The decorated class is a static class , Can't be instantiated .

Class name ： The class name is used to describe the function of a class . Class names are unique in the same namespace .

Members of the class ： Elements defined in the class , It mainly includes Field 、 attribute 、 Method .

Class member access modifier ：

public： Members can be accessed by any code .

private： Members can only be accessed by code in the same class , If the access modifier is not used before the class member , The default is private

internal Members can only be accessed by code in the same project .

protected Members can only have code access to classes or derived classes .

Member modifier ：readonly（ read-only ）、static（ Static class ） and const（ Constant ）, Three cannot decorate the same member .

       readonly Decorating a field means that you can only read the value of the field and cannot assign a value to the field .

static The decorated field is a static field , The modified class is called static class , You can access this field directly through the class name .

about static For members , It doesn't belong to any object , It belongs to all objects , The current class .

example ：static int personCount  = 0;

const Constants cannot be accessed externally , All names are required to be capitalized .

example ：public const string TYPE = " A good man ";

  public string GetPersonType()

        {

            return TYPE;

        }

C# The method in

Method definition

grammar ： Access modifier   Modifier   return type Method name （ parameter list ）{ Sentence block }

example ：

 

 

explain ：

Access modifier ： All class member modifiers can use , The default is private.

Modifier ： Yes virtual（ Virtual ）、abstract（ In the abstract ）、override（ Rewrite the ）、static（ Static ）、sealed（ Sealed ）.

virtual Set the method to virtual , Is a key modifier

abstract A modified class is called an abstract class and will be defined by a derived class , The method of modification is called abstract method .

override Is inherited between classes, is used .

sealed The seal cannot be rewritten . uninheritable

static Static modification method is called static modification method , The modified class is called static class .

Static and non static members are called difference ：

Non static members ：1 Need to be called by the object 2. Static members can be called

Static members ：1 Can only be called by class name 2. Non static members cannot be called

return type ： Use if there is a return value return, If there is no return value, use void

Method name ： use Pascal Nomenclature , Capitalize each word .

parameter list ： There can be 0 To more than one , Keep parentheses without parameters , Multiple are separated by commas . The form of the definition （ data type Parameter name ）

example ：static void AddOne(int value)

        {

            value++;

        }

get and set accessor

For classes, attributes are generally not exposed , Realization get and set The accessor is encapsulated . Used for value taking and assignment .

example ：string name;

        public String Name

        {

            get { return name; }

            set { name = value + "_1";}

        }

example ：public int sex { get; set; }