我正在开发一个“银行帐户”类型的程序,我的目标是取款和存钱,显示更新的余额,显示帐户状态( overdraw 与否)。我刚刚得到了添加/减去和更新平衡工作,但是我的 JTextFields 中的数字是绝对值,并且不显示负余额(余额 < 0)。我需要做某种格式吗?我已经包含了按钮监听器的代码以及我所做的一些解析将 double 转换为字符串等。请帮忙!
depositButton.addActionListener(new DepositListener());
withdrawButton.addActionListener(new WithdrawListener());
//create object of BankAccount, assign values to the text fields
BankAccount myAcct = new BankAccount(1524687, 100.00, "Landon Wiggs");
acctNameF.setText(myAcct.getName() );
acctNumF.setText(Integer.toString( myAcct.getAcctNumber() ) );
acctBalanceF.setText( Double.toString(myAcct.getBalance()));
depositWithdrawAmtF.setText("0.00");
private class DepositListener implements ActionListener
{
public void actionPerformed (ActionEvent event)
{
double sum = Double.valueOf(depositWithdrawAmtF.getText()) + Double.valueOf(acctBalanceF.getText());
double amt = (Double.parseDouble(depositWithdrawAmtF.getText()));
acctBalanceF.setText(Double.toString(sum));
}
}
private class WithdrawListener implements ActionListener {
public void actionPerformed (ActionEvent event) {
double sum = (Double.valueOf(depositWithdrawAmtF.getText() )) - (Double.valueOf(acctBalanceF.getText() ));
double amt = (Double.parseDouble(depositWithdrawAmtF.getText()));
acctBalanceF.setText(Double.toString(sum));
}
}
最佳答案
当您提款时,您可能应该从账户资金中减去提款金额,现在您正在做相反的事情。
改变
double sum = (Double.valueOf(depositWithdrawAmtF.getText() )) - (Double.valueOf(acctBalanceF.getText() ));
至
double sum = Double.valueOf(acctBalanceF.getText()) - Double.valueOf(depositWithdrawAmtF.getText());
关于java - JTextField只显示绝对值,没有负号?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/29501182/