java - 取消按钮必须有一个功能

Question

我在使用此取消按钮时遇到问题。

使用这些代码:

int deposit;
String dep =
   JOptionPane.showInputDialog("How much would you like to deposit?\n\t$: ");
deposit = Integer.parseInt(dep);

应该出现“确定”和“取消”按钮，但每当我单击取消按钮时，都没有任何响应。我想要的是，每当我单击“取消”按钮时，它都应该返回到主菜单，但是如何返回呢？

代码:

private static void processDeposit(String num, int rc){
    int deposit;
    String dep =
        JOptionPane.showInputDialog(
            "How much would you like to deposit?\n\t$: ");
    deposit = Integer.parseInt(dep);
    JOptionPane.showMessageDialog(
        null, "You have deposited $" + dep + " into the account of " + name);
    myAccount.setBalance(myAccount.getBalance() + deposit);
}

Answer 1

如果用户点击取消 dep 将返回 null

所以你可以这样做:

 if(input == null || (input != null && ("".equals(input))))   
 {

         //what you ever you need to do here

 }