Question

我是C＃的新手，并且已经开始研究这个项目了。我修复了以前的问题并完成了一个工作程序。但是，我现在陷入了一个新问题。我有一个提取或存款的银行业务计划，并增加了初始余额。但是，在初始存款或取款后，我无法更新到新的余额。

TL; DR：初始余额= 1000.存款为100.新余额= 1100.另外存款100，不会更新，余额将保持在1100.

Account.cs

namespace Account_Teller
{
    class Account
   {   

    private decimal _amount;
    public decimal balance;

    public decimal Balance { get; }

    public Account (decimal pBalance)
    {
        this.Balance = pBalance;
    }

    public decimal Amount
    {
        get
        {
            return _amount;              
        }
        set
        {
            if (value < 0)
            {
                throw new ArgumentException("Please enter an amount greater than 0");                  
            }
            else
            {
                _amount = value;
            }
        }
    }

    public decimal Deposit()
    {          
        balance = Balance + _amount;
        return balance;
    }

    public decimal Withdrawl()
    {                    

        balance = Balance - _amount;


        if (balance < 0)
        {
            throw new ArgumentException("Withdrawing " + _amount.ToString("C") + " would leave you overdrawn!");
        }
        return balance;
    }
}

}

Main.cs

namespace Account_Teller
{
public partial class Form1 : Form
{


    public Form1()
    {
        InitializeComponent();
    }

    Account acc = new Account(1000);


    private void btnWithdraw_Click(object sender, EventArgs e)
    {
        lblBalance.Text = acc.Balance.ToString("C");
        try
        {               
            acc.Amount = decimal.Parse(txtAmount.Text);               
            lblBalance.Text = acc.Withdrawl().ToString("C");               
        }
        catch (FormatException ex)
        {
            MessageBox.Show(ex.Message);
        }
        catch (ArgumentException ex)
        {
            MessageBox.Show(ex.Message);
        } 
        catch (Exception error)
        {
            MessageBox.Show(error.Message);
        }
    }

    private void btnDeposit_Click(object sender, EventArgs e)
    {
        try
        {

            acc.Amount = decimal.Parse(txtAmount.Text);                
            lblBalance.Text = acc.Deposit().ToString("C");
        }
        catch (FormatException ex)
        {
            MessageBox.Show(ex.Message);
        }    
        catch (ArgumentException ex)
        {
            MessageBox.Show(ex.Message);
        }
        catch (Exception error)
        {
            MessageBox.Show(error.Message);
        }
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        lblBalance.Text = acc.Balance.ToString("C");
    }
}

}

Answer 1

您的代码中没有任何内容将属性Balance绑定到字段balance。就C＃而言，它们是两个独立的变量。

您的Balance应该定义为：

public decimal Balance { get; private set; }

那么你根本就没有balance字段。

你班上的其他人应该是这样的：

public class Account
{
    public decimal Balance { get; private set; }

    public Account(decimal balance)
    {
        this.Balance = balance;
    }

    public void Deposit(decimal amount)
    {
        if (amount < 0m)
        {
            throw new ArgumentException("Please enter an amount greater than 0");
        }
        this.Balance = this.Balance + amount;
    }

    public void Withdraw(decimal amount)
    {
        if (this.Balance - amount < 0m)
        {
            throw new ArgumentException("Withdrawing " + amount.ToString("C") + " would leave you overdrawn!");
        }
        this.Balance = this.Balance - amount;
    }
}

这将是此代码的更典型的实现。

然后您将编写此类代码以使用该类：

acc.Withdraw(decimal.Parse(txtAmount.Text));
lblBalance.Text = acc.Balance.ToString("C");

Answer 2

因为您没有在余额和余额之间设置约束。有一点，不要将平衡公开为公共

BiomeType playerCurrentBiomeType;
LocationType playerCurrentLocationType;
LoadLevel(myDictionary[playerCurrentBiomeType][playerCurrentLocationType]);

//ex. myDictionary[BiomeType.Jungle][LocationType.CapitalCity]
//ex. myDictionary[BiomeType.Desert][LocationType.CapitalCity]
//ex. myDictionary[BiomeType.Desert][LocationType.City3]

每次提款或存款后更新余额

2 个答案: