摘自：MSDN
The situation is similar to personal secrets (shared only with friends), family secrets (shared with friends and children), and nonsecrets (shared with anybody), respectively.
A Partial:It is possible to split the definition of a class or a struct, or an interface over two or more source files. Each source file contains a section of the class definition, and all parts are combined when the application is compiled.
please see the following example code:
public partial class CoOrds
{
private int x;
private int y;
public CoOrds(int x, int y)
{
this.x = x;
this.y = y;
}
}
public partial class CoOrds
{
public void PrintCoOrds()
{
System.Console.WriteLine("CoOrds: {0},{1}", x, y);
}
}
class TestCoOrds
{
static void Main()
{
CoOrds myCoOrds = new CoOrds(10, 15);
myCoOrds.PrintCoOrds();
}
}
A private: member of a class is accessible only by members and friends of the class.
See the following example code:
using System;
class Employee
{
private string name = "FirstName, LastName";
private double salary = 100.0;
public string GetName()
{
return name;
}
public double Salary
{
get { return salary; }
}
}
class MainClass
{
static void Main()
{
Employee e = new Employee();
// The data members are inaccessible (private), so
// then can't be accessed like this:
// string n = e.name;
// double s = e.salary;
// 'name' is indirectly accessed via method:
string n = e.GetName();
// 'salary' is indirectly accessed via property
double s = e.Salary;
}
}
A protected: member of a class is accessible by members and friends of the class and by members and friends of derived classes, provided they access the base member via a pointer or a reference to their own derived class.
please see the following example code:
using System;
class A
{
protected int x = 123;
}
class B : A
{
static void Main()
{
A a = new A();
B b = new B();
// Error CS1540, because x can only be accessed by
// classes derived from A.
// a.x = 10;
// OK, because this class derives from A.
b.x = 10;
}
}
A public: member of a class is accessible by everyone.
See the following example code:
using System;
class Point
{
public int x;
public int y;
}
class MainClass
{
static void Main()
{
Point p = new Point();
// Direct access to public members:
p.x = 10;
p.y = 15;
Console.WriteLine("x = {0}, y = {1}", p.x, p.y);
}
}
A Property: Member is a generic term that refers to a field, property, or method of a class. A field is a variable, a property is a bit of data, and a method is a function/subroutine. For example:
public class BankAccount
{
private int _balance;
public int Balance
{
get { return _balance; }
set { _balance = value; }
}
public void Deposit(int depositAmount)
{
// I can reference _balance here because I'm inside the class that defined it
_balance = _balance + depositAmount;
}
}
The above C# code represents a class. _balance (field), Balance (property), and Deposit (method) are all "members" of the class.
Think of a class as a blueprint. A blueprint isn't a house, it's the definition of what the house will look like when you build it. You "build" an object from a class by "new"ing it.
public class Bank
{
public void Main()
{
// ba represents an object created from the class BankAccount
BankAccount ba = new BankAccount();
// This won't compile because _balance is private so it is not accessible outside the class
ba._balance = 10;
// This works fine because Balance is public, so it is accessible from this code that
// exists outside of the class definition for BankAccount
ba.Balance = 10;
}
}