19. Status Person mode (state pattern)

usingSystem;usingSystem.Collections.Generic;usingSystem.Linq;usingSystem.Text;usingSystem.Threading.Tasks;namespaceconsoleapplication2{classProgram {//each object has its corresponding state, and each state corresponds to some corresponding behavior, and if an object has more than one state,//Then there will be a lot of action. Then the judgment of these States and the behavior done according to the state will result in multiple conditional statements,//and if you add a new state, you need to change the previously existing code.        Such a design clearly violates the principle of opening and shutting. //state patterns are used to solve such problems. The state pattern abstracts the behavior of each state into a separate new object,//changes in this state no longer depend on the behavior within the object. //Account class: Maintains an instance of the State class that identifies the status of the current object. //State Class: A class of abstract states that defines the behavior conventions that a specific State class needs to implement. //Silvestater, Goldstate, and RedState classes: specific state classes that implement each behavior of the abstract State class.         Static voidMain (string[] args) {            //open a new account.Account Account =NewAccount ("Learning Hard"); //to Trade//SaveAccount. Deposit (1000.0); Account. Deposit (200.0); Account. Deposit (600.0); //Pay InterestAccount .            Payinterest (); //Withdraw MoneyAccount. Withdraw (2000.00); Account. Withdraw (500.00); //wait for user inputConsole.readkey (); }    }    /// <summary>    ///Account/// </summary>     Public classAccount { PublicState State {Get;Set; }  Public stringOwner {Get;Set; }  PublicAccount (stringowner) {             This. Owner =owner;  This. State =NewSilverstate (0.0, This); }         Public DoubleBalance {Get{returnState.balance; } }//Balance//Save         Public voidDeposit (Doubleamount)            {state.deposit (amount); Console.WriteLine ("Deposit amount is {0:c}--", amount); Console.WriteLine ("account balance is =:{0:c}", This.            Balance); Console.WriteLine ("The account status is: {0}", This. State.gettype ().            Name);        Console.WriteLine (); }        //Withdraw Money         Public voidWithdraw (Doubleamount)            {State.withdraw (amount); Console.WriteLine ("withdrawal amount is {0:c}--", amount); Console.WriteLine ("account balance is =:{0:c}", This.            Balance); Console.WriteLine ("The account status is: {0}", This. State.gettype ().            Name);        Console.WriteLine (); }        //Earn Interest         Public voidpayinterest () {state.payinterest (); Console.WriteLine ("Interest Paid---"); Console.WriteLine ("account balance is =:{0:c}", This.            Balance); Console.WriteLine ("The account status is: {0}", This. State.gettype ().            Name);        Console.WriteLine (); }    }    //Abstract State Class     Public Abstract classState {//Properties         PublicAccount Account {Get;Set; }  Public DoubleBalance {Get;Set; }//Balance         Public DoubleInterest {Get;Set; }//Interest Rate         Public DoubleLowerlimit {Get;Set; }//Lower Limit         Public DoubleUpperlimit {Get;Set; }//Upper Limit         Public Abstract voidDeposit (DoubleAmount);//Deposit         Public Abstract voidWithdraw (DoubleAmount);//Withdraw Money         Public Abstract voidPayinterest ();//the interest earned    }    //Red state means the account is overdrawn.     Public classRedstate:state { PublicRedState (state state) {//Initialize             This. Balance =State .            Balance;  This. Account =State .            account; Interest=0.00; Lowerlimit= -100.00; Upperlimit=0.00; }        //Deposit         Public Override voidDeposit (Doubleamount) {Balance+=amount;        Statechangecheck (); }        //Withdraw Money         Public Override voidWithdraw (Doubleamount) {Console.WriteLine ("There's no money to take! "); }         Public Override voidpayinterest () {//No Interest        }        Private voidStatechangecheck () {if(Balance >upperlimit) {Account.state=NewSilverstate ( This); }        }    }    //the Silver state means that there is no interest     Public classSilverstate:state { Publicsilverstate (state): This(state. Balance, state. account) {} PublicSilverstate (Doublebalance, account account) {             This. Balance =balance;  This. Account =Account ; Interest=0.00; Lowerlimit=0.00; Upperlimit=1000.00; }         Public Override voidDeposit (Doubleamount) {Balance+=amount;        Statechangecheck (); }         Public Override voidWithdraw (Doubleamount) {Balance-=amount;        Statechangecheck (); }         Public Override voidpayinterest () {Balance+ = Interest *Balance;        Statechangecheck (); }        Private voidStatechangecheck () {if(Balance <lowerlimit) {Account.state=NewRedState ( This); }            Else if(Balance >upperlimit) {Account.state=NewGoldstate ( This); }        }    }    //Gold state means interest status.     Public classGoldstate:state { Publicgoldstate (state state) { This. Balance =State .            Balance;  This. Account =State .            account; Interest=0.05; Lowerlimit=1000.00; Upperlimit=1000000.00; }        //Save         Public Override voidDeposit (Doubleamount) {Balance+=amount;        Statechangecheck (); }        //Withdraw Money         Public Override voidWithdraw (Doubleamount) {Balance-=amount;        Statechangecheck (); }         Public Override voidpayinterest () {Balance+ = Interest *Balance;        Statechangecheck (); }        Private voidStatechangecheck () {if(Balance <0.0) {account.state=NewRedState ( This); }            Else if(Balance <lowerlimit) {Account.state=NewSilverstate ( This); }        }    }}

19. Status Person mode (state pattern)