namespace SingleResponsibilityPrinciple
{class DataAccess{void InsertData(){Console.WriteLine("数据插入成功");}// 错误的设计，不符合 单一职责原则//void WriteLog()//{//    Console.WriteLine("日志插入成功");//}
    }// 应该把不同的职责交给不同的对象处理class Logger{void WriteLog(){Console.WriteLine("日志插入成功");}}
}

namespace OpenClosePrinciple
{abstract class DataProvider{public abstract void OpenConnection();public abstract void CloseConnection();public abstract void ExecuteCommand();}// MS SQLclass SqlDataProvider:DataProvider{public override void OpenConnection(){Console.WriteLine("打开Sql数据连接");}public override void CloseConnection(){Console.WriteLine("关闭Sql数据连接");}public override void ExecuteCommand(){Console.WriteLine("执行Sql数据命令");}}// ORACLEclass OracleDataProvider:DataProvider{public override void OpenConnection(){Console.WriteLine("打开Oracle数据连接");}public override void CloseConnection(){Console.WriteLine("关闭Oracle数据连接");}public override void ExecuteCommand(){Console.WriteLine("执行Oracle数据命令");}}class Start{void Invoke(){DataProvider dataProvider = new SqlDataProvider();dataProvider.OpenConnection();dataProvider.ExecuteCommand();dataProvider.CloseConnection();dataProvider = new OracleDataProvider();dataProvider.OpenConnection();dataProvider.ExecuteCommand();dataProvider.CloseConnection();}}
}

namespace LiskovSubstitutionPrinciple
{class Rectangle{protected int width = 0;protected int height = 0;public virtual void SetWidth(int width){this.width = width;}public virtual void SetHeight(int height){this.height = height;}public virtual int GetArea(){return this.width * this.height;}}class Square : Rectangle{public override void SetHeight(int height){this.height = height;this.width = height;}public override void SetWidth(int width){this.height = width;this.width = width;}}class Start{public static Rectangle CreateInstance(int condition = 1){if (condition == 1){return new Rectangle();}else{return new Square();}}public static void Invoke(){Rectangle rectangleObject = CreateInstance();rectangleObject.SetHeight(10);rectangleObject.SetWidth(20);rectangleObject.GetArea();}}
}

namespace InterfaceSegregationPrinciple
{interface IDataProvider{void OpenConnection();void CloseConnection();}interface ISqlDataProvider : IDataProvider{void ExecuteSqlCommand();}interface IOracleDataProvider : IDataProvider{void ExecuteOracleCommand();}class SqlDataProvider : ISqlDataProvider{public void ExecuteSqlCommand(){Console.WriteLine("执行Sql数据命令");}public void OpenConnection(){Console.WriteLine("打开Sql数据连接");}public void CloseConnection(){Console.WriteLine("关闭Sql数据连接");}}class OracleDataProvider : IOracleDataProvider{public void ExecuteOracleCommand(){Console.WriteLine("执行Oracle数据命令");}public void OpenConnection(){Console.WriteLine("打开Oracle数据连接");}public void CloseConnection(){Console.WriteLine("关闭Oracle数据连接");}}class Start{public void Invoke(){ISqlDataProvider sqlDataProvider = new SqlDataProvider();sqlDataProvider.OpenConnection();sqlDataProvider.ExecuteSqlCommand();sqlDataProvider.CloseConnection();IOracleDataProvider oracleDataprovider = new OracleDataProvider();oracleDataprovider.OpenConnection();oracleDataprovider.ExecuteOracleCommand();oracleDataprovider.CloseConnection();}}
}

namespace DependencyInversionPrinciple
{interface IBankAccount{long BankNumber { get; set; } // 卡号decimal Balance { get; set; } // 余额
    }// 转账人interface ITransferSource : IBankAccount{void CutPayment(decimal value);}// 收款人interface ITransferDestination : IBankAccount{void AddMoney(decimal value);}class BankAccout : IBankAccount, ITransferSource, ITransferDestination{public long BankNumber { get; set; }public decimal Balance { get; set; }public void CutPayment(decimal value){Balance -= value;}public void AddMoney(decimal value){Balance += value;}}class TransferAmount{public decimal Amount { get; set; }public void Transfer(ITransferSource source, ITransferDestination dest){source.CutPayment(Amount);dest.AddMoney(Amount);}}class Start{void Invoke(){ITransferSource source = new BankAccout { Balance = 10000, BankNumber = 111 };ITransferDestination dest = new BankAccout { Balance = 1, BankNumber = 222 };TransferAmount transfer = new TransferAmount();transfer.Amount = 9999; // 转多少钱transfer.Transfer(source, dest); // 开始转账// 这是用依赖反转的思维做一个银行转账的功能，使银行账户可以依赖ITransferSource，ITransferDestination// 而不是以前直接 BankAccout account = new BankAccout();大大增加了账户这个核心对象的灵活性// 这个例子基本上有SOLID原则的所有身影
        }}// 附上一个普通版的 做下对比，用中文名做变量，通俗易懂吧class 银行账户{public int 卡号 { get; set; }public decimal 余额 { get; set; }public void 存入(decimal value){余额 += value;}public void 支出(decimal value){余额 -= value;}}class 银行转账操作 //ATM
    {public 银行账户 转账人 { get; set; }public 银行账户 收款人 { get; set; }public decimal 金额 { get; set; }public void 转账(){转账人.支出(金额);收款人.存入(金额);}}class Start1{public void Main(){银行账户 张三 = new 银行账户 { 卡号 = 111, 余额 = 10000 };银行账户 李四 = new 银行账户 { 卡号 = 222, 余额 = 5 };银行转账操作 转账 = new 银行转账操作();转账.金额 = 1000;转账.转账人 = 张三;转账.收款人 = 李四;转账.转账();}}
}