比赛日 - 金额大于现金

Question

我目前正在处理一本书为我分配的项目（Head First C＃，3rd Edition），我的代码遇到了一些问题。

整个项目基于3个人可以参与的赌博游戏。

赌博游戏包括投注4只狗的3个人，可以在赛道上随机赢得比赛。

其中一个问题是当一个人投入的金额比他更多时，该计划将金额的值设为0.

我不知道为什么我没有看到明显的错误，但如果有人愿意，我真的很感激帮助。

整个计划的代码如下：

的 Guy.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace A_Day_at_the_Races
{
 public class Guy
{
    public string Name; // The guy's name
    public Bet MyBet = null; // An instance of Bet() that has how much he's betting
    public int Cash; // How much cash he has
    // These last two fields are the guy's GUI controls on the form
    public RadioButton MyRadioButton; // My RadioButton
    public Label MyLabel; // My Label

    public void UpdateLabels()
    {
        //1.Set my label to my bet's description, 
        if (MyBet == null)
            MyLabel.Text = Name + " hasnt placed any bets";
        else if (MyBet.Amount > Cash)
            MyLabel.Text = Name + " doesn't have that amount of money";
        else
            MyLabel.Text = MyBet.GetDescription();
        if (Cash >= 0)
        {
            //2.Set the label on my radio button to show my cash ("Joe has 43 dollars")
            MyRadioButton.Text = Name + " has " + Cash + " bucks";
        }
        else
        {
            MyRadioButton.Text = Name + " has no cash left";
        }
    }

    public void ClearBet()
    {
        //1.Reset my bet so it's zero
        MyBet = null;
    }



    public bool PlaceBet(int Amount, int Dog)
    {
        //1.Place a new bet and store it in my bet field
        this.MyBet = new Bet();

        //2.Return true if the guy had enough money to bet
        if (Cash >= Amount)
        {

            Cash = Cash - Amount; // Remove the amount bet
            MyBet.Amount = Amount;
            MyBet.Dog = Dog;
            MyBet.Bettor = this;
            UpdateLabels();
            return true;
        }
        else if (Cash < Amount)
        {
            return false;
        }
        else
        {
            return false;
        }
    }

    public void Collect(int Winner)
    {
        if (MyBet != null)
            //1.Ask my bet to pay out (hint use the bet object to do the work)
            Cash += MyBet.PayOut(Winner);
    }
  }
}    

的 Greyhound.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Drawing;

namespace A_Day_at_the_Races
{
 public class Greyhound
  {
    public int StartingPosition; // Where PictureBox starts
    public int RacetrackLength; // How long the racetrack is
    public PictureBox MyPictureBox = null; // My PictureBox object
    public int Location = 0; // My location on the racetrack
    public Random Randomizer; // An instance of Random

    public bool Run()
    {
        // Move forward either 1, 2, 3 or 4 spaces at random
        int x = Randomizer.Next(1, 4);

        // Update the position of my PictureBox on the form
        Point p = MyPictureBox.Location;
        p.X += x;
        MyPictureBox.Location = p;

        // Return true if I won the game
        if (p.X >= RacetrackLength)
        {
            return true;
        }
        else
        {
            return false;
        }
    }
    public void TakeStartingPosition ()
    {
        // Reset starting position of PictureBox
        StartingPosition = 0;
    }
  }
}

的 Bet.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace A_Day_at_the_Races
{
  public class Bet
  {
    public int Amount; // The amount of cash that was bet
    public int Dog; // The number of the dog the bet is on
    public Guy Bettor = new Guy(); // The guy who placed the bet

    public string GetDescription()
    {
        // Return a string that says who placed the bet, how much cash 
        // was bet, and which dog he bet on ("Joe bets 8 on dog #4").
        if (Amount > 0 && Amount < Bettor.Cash)
        {
            return Bettor.Name + " bets $" + Amount + " on dog #" + Dog; 
        }
        // If the amount is zero, no bet was placed; ("Joe hasn't placed
        // a bet").
        else if (Amount == 0)
        {
            return Bettor.Name + " hasn't placed a bet";
        }
        else if (Amount > Bettor.Cash)
        {
            return Bettor.Name + " doesn't have that amount of money";
        }
        else
        {
            return Bettor.Name + "'s bet";
        }

    }

    public int PayOut(int Winner) // The parameter is the winner of the race
    {
        // If the dog won, return the amount bet.
        if (Winner == Dog)
        {
            return Amount;
        }
        // Otherwise, return the negative of the amount bet.
        else
        {
            return -1 * Amount;
        }
    }
  }
}

的 Form1.cs的

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace A_Day_at_the_Races
{
  public partial class Form1 : Form
  {
    Guy[] Bettors;
    Greyhound[] Dogs;
    Guy CurrentBettor;

    public Form1()
    {
        InitializeComponent();
        Random Randomizer = new Random();

        // Initialise all my Guys and Dogs
        Bettors = new Guy[3];
        Dogs = new Greyhound[4];

        // Guys

            // Joe
            Bettors[0] = new Guy();
            Bettors[0].Name = "Joe";
            Bettors[0].MyRadioButton = joeRadioButton;
            Bettors[0].MyLabel = joeBetLabel;
            Bettors[0].Cash = 50;
            Bettors[0].UpdateLabels();

            // Bob
            Bettors[1] = new Guy();
            Bettors[1].Name = "Bob";
            Bettors[1].MyRadioButton = bobRadioButton;
            Bettors[1].MyLabel = bobBetLabel;
            Bettors[1].Cash = 75;
            Bettors[1].UpdateLabels();

            // Al
            Bettors[2] = new Guy();
            Bettors[2].Name = "Al";
            Bettors[2].MyRadioButton = alRadioButton;
            Bettors[2].MyLabel = alBetLabel;
            Bettors[2].Cash = 45;
            Bettors[2].UpdateLabels();

        // Local integers on distance and starting position of the Dogs
        int StartPosition = pictureBoxDog1.Location.X;
        int distance = pictureBox1.Width;

        // Initialize all 4 Dogs
        for (int i = 0; i < Dogs.Length; i++)
        {
            Dogs[i] = new Greyhound();
            Dogs[i].Randomizer = Randomizer;
            Dogs[i].RacetrackLength = distance;
            Dogs[i].Location = Dogs[i].StartingPosition = StartPosition;
        }

        // Connect pictureboxes with MyPictureBox in the Dog class
        Dogs[0].MyPictureBox = pictureBoxDog1;
        Dogs[1].MyPictureBox = pictureBoxDog2;
        Dogs[2].MyPictureBox = pictureBoxDog3;
        Dogs[3].MyPictureBox = pictureBoxDog4;

        CurrentBettor = Bettors[0];
    }

    private void RaceButton_Click(object sender, EventArgs e)
    {
        int winner = 0; // Number of the winner Dog
        int num_winners = 0; // Amount of winners

        // While none has won, 
        while (num_winners == 0)
        {
            for (int i = 0; i < Dogs.Length; i++)
            {
                // If a Dog has reached max length of the race track,
                // increment number of winners and add 1 to i and save it 
                // to the winner variable
                if (Dogs[i].Run())
                {
                    num_winners++;
                    winner = i + 1;
                }
            }
            Application.DoEvents();
            System.Threading.Thread.Sleep(3);
        }
        // If there is more than one winner, show this message
        if (num_winners > 1)
            MessageBox.Show("We have " + num_winners + " winners");
        // Otherwise if there are more than or equal to one winner,
        // show this message
        else if (num_winners >= 1)
            MessageBox.Show("Dog #" + winner + " wins!");

        // Place all Dogs in their starting positions
        for (int i = 0; i < Dogs.Length; i++)
        {
            Dogs[i].TakeStartingPosition();
        }

        for (int i = 0; i < Bettors.Length; i++)
        {
            Bettors[i].Collect(winner);
            Bettors[i].ClearBet();
            Bettors[i].UpdateLabels();
        }

        numericUpDownBet.Value = numericUpDownBet.Minimum;
        numericUpDownDog.Value = numericUpDownDog.Minimum;
    }

    private void joeRadioButton_CheckedChanged(object sender, EventArgs e)
    {
        // Bettor = Joe when his radio button is checked
        SetBettor(0);
    }

    private void bobRadioButton_CheckedChanged_1(object sender, EventArgs e)
    {
        // Bettor = Bob when his radio button is checked
        SetBettor(1);
    }

    private void alRadioButton_CheckedChanged_1(object sender, EventArgs e)
    {
        // Bettor = Al when his radio button is checked
        SetBettor(2);
    }

    private void BetsButton_Click(object sender, EventArgs e)
    {
        // Place bet depending on the value of the two numericUpDowns
        // (Amount & Dog)
        CurrentBettor.PlaceBet((int)numericUpDownBet.Value, (int)numericUpDownDog.Value);
        CurrentBettor.UpdateLabels();
    }
    private void SetBettor(int index)
    {
        // Set the current bettor and update the name label
        // to the his name
        CurrentBettor = Bettors[index];
        NameLabel.Text = CurrentBettor.Name;

        // If the Guy's bet isn't 0,
        // then save the amount and the dog he's
        // betting on
        if (CurrentBettor.MyBet != null)
        {
            numericUpDownBet.Value = CurrentBettor.MyBet.Amount;
            numericUpDownDog.Value = CurrentBettor.MyBet.Dog;
        }
        // Otherwise, make the value of the bet
        // to the minimum on the numericUpDownBet
        // and set the default Dog that is being
        // bet on as the first Dog
        else
        {
            numericUpDownBet.Value = numericUpDownBet.Minimum;
            numericUpDownDog.Value = 1;
        }
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        minimumBetLabel.Text = "Minimum Bet: $5.00";
    }

    private void ResetButton_Click(object sender, EventArgs e)
    {
        // Reset Dogs to their default location when 
        // the Reset button is pressed
        pictureBoxDog1.Location = new Point(22, 21);
        pictureBoxDog2.Location = new Point(22, 63);
        pictureBoxDog3.Location = new Point(22, 120);
        pictureBoxDog4.Location = new Point(22, 170);
    }
  }
}

感谢所有答案。

Answer 1

问题出在以下代码中。

在这里，创建了一个新的赌注（Amount默认为0，否则设置为！）：

    //1.Place a new bet and store it in my bet field
    this.MyBet = new Bet();

此处，所有相关数据均设为MyBet：

    //2.Return true if the guy had enough money to bet
    if (Cash >= Amount)
    {
        Cash = Cash - Amount; // Remove the amount bet
        MyBet.Amount = Amount;
        MyBet.Dog = Dog;
        MyBet.Bettor = this;
        UpdateLabels();
        return true;
    }

此处，没有为MyBet设置数据，因此Amount仍为0：

    else if (Cash < Amount)
    {
        return false;
    }

这根本不会发生：

    else
    {
        return false;
    }

Answer 2

我PlaceBet - 你创建一个空的Bet，然后检查，如果这个人有足够的现金。如果他没有，那么空投注将保持为空 - 其金额字段将保持默认值0。

public bool PlaceBet(int Amount, int Dog)
{
    //1.Place a new bet and store it in my bet field
    this.MyBet = new Bet();   // EMPTY BET

    //2.Return true if the guy had enough money to bet
    if (Cash >= Amount)
    {

        Cash = Cash - Amount; // Remove the amount bet
        MyBet.Amount = Amount;
        MyBet.Dog = Dog;
        MyBet.Bettor = this;
        UpdateLabels();
        return true;
    }
    else if (Cash < Amount)
    {
        // THE BET REMAINS EMPTY
        return false;
    }
    else
    {
        return false;
    }
}

此外，＆＃34;其他＆＃34;块永远不会发生 - 您实际上可以删除else if (Cash < Amount)案例。

Answer 3

    //1.Place a new bet and store it in my bet field
    this.MyBet = new Bet();

    //2.Return true if the guy had enough money to bet
    if (Cash >= Amount)
    {

        Cash = Cash - Amount; // Remove the amount bet
        MyBet.Amount = Amount;
        MyBet.Dog = Dog;
        MyBet.Bettor = this;
        UpdateLabels();
        return true;
    }
    else if (Cash < Amount)
    {
        return false;
    }

在（1）你正在创建一个新的Bet对象然后如果Cash＆lt;数量为（2）你返回false而不设置this.MyBet为null。

最好的解决方案可能就是把这个.MyBet = new Bet（）;现金＆gt; =金额块。