showInputDialog - 单击取消选项

Question

如果用户在inputDialog上点击了Cancel，如何处理？我已经尝试过以前发布的解决方案，但都没有奏效。

这是我的代码

String bidString = JOptionPane.showInputDialog(null, "Place your bid ", "Bid",
                JOptionPane.PLAIN_MESSAGE);

    while(bidString.isEmpty())
    {
        JOptionPane.showMessageDialog(null,"You must enter a value",
                    "The Numbers Game", JOptionPane.ERROR_MESSAGE);

        bidString = JOptionPane.showInputDialog(null, "How much do you wish to bid?", "Initial funds"
                ,JOptionPane.QUESTION_MESSAGE);

        if(bidString != null)
        {
            return;
        }

    }
    int bid = Integer.parseInt(bidString);

Answer 1

试试这样：

String bidString;
while (true) {
    bidString = JOptionPane.showInputDialog(null, "Place your bid ", "Bid",
            JOptionPane.PLAIN_MESSAGE);
    if (bidString == null) {
        System.out.println("cancelled");
        break;
    }
    if (bidString.isEmpty()) {
        System.out.println("wrong entry");
        JOptionPane.showMessageDialog(null, "You must enter a value",
                "The Numbers Game", JOptionPane.ERROR_MESSAGE);
        continue;
    }else{
        try {
            int bid = Integer.parseInt(bidString);
        } catch (NumberFormatException nfe) {
            System.out.println("no number entered");
            continue;
        }
        break;
    }
}