java使用JOptionPane按钮创建条件状态

Question

有没有一种方法可以为JOptionPane.showInputDialog()中的ok和cancel按钮创建单独的条件语句
我之所以要这样做，是因为我不希望将空字符串或充满空格的字符串设置为s
当我用一个空文本字段单击“确定”或单击“取消”时，s将被设置为null
是否有一种方法可以为“确定”和“取消”按钮选择不同的选项，如果单击“取消”，窗口将关闭，如果单击“确定”，代码将继续执行条件语句

public boolean stringIsNullOrOnlyWhiteSpaces(String s)  {
   //checks if string is null or if string only contains white spaces
}


private void nameOfString() {
String s = JOptionPane.showInputDialog(this, "Enter String Name");

if (!stringIsNullOrOnlyWhiteSpaces(s)) {
   // do action    
  }

else { // if "ok" were to be clicked and not "cancel"
JOptionPane.showMessageDialog(this, "String cannot be empty");
nameOfString();
}
}

Answer 1

我怀疑是否有一种方法可以让你仅仅使用JOptionPane，他们应该只是捕捉一个值，在.showInputMessage()的情况下，它是一个字符串

正确的方法是使用JDialog并添加包含其逻辑的组件

我对这份工作很厌烦，所以我做了一些我认为对你们有用的事情：

public class CustomInput {

private JButton btAccept;
private JButton btCancel;
private JLabel lbInput;
private JTextField tfInput;
private JPanel pnDialog;

private JPanel createPanel() {
    java.awt.GridBagConstraints gridBagConstraints;
    pnDialog = new JPanel();
    lbInput = new JLabel();
    tfInput = new JTextField();
    btAccept = new JButton();
    btCancel = new JButton();

    pnDialog.setLayout(new java.awt.GridBagLayout());

    btAccept.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            btAcceptAction(evt);
        }
    });

    btCancel.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            btCancelAction(evt);
        }
    });

    lbInput.setText("Enter your input.");
    gridBagConstraints = new java.awt.GridBagConstraints();
    gridBagConstraints.gridx = 1;
    gridBagConstraints.gridy = 0;
    gridBagConstraints.gridwidth = 2;
    pnDialog.add(lbInput, gridBagConstraints);

    tfInput.setText("");
    tfInput.setColumns(10);
    gridBagConstraints = new java.awt.GridBagConstraints();
    gridBagConstraints.gridx = 1;
    gridBagConstraints.gridy = 1;
    gridBagConstraints.gridwidth = 2;
    pnDialog.add(tfInput, gridBagConstraints);

    btAccept.setText("Accept");
    gridBagConstraints = new java.awt.GridBagConstraints();
    gridBagConstraints.gridx = 1;
    gridBagConstraints.gridy = 2;
    pnDialog.add(btAccept, gridBagConstraints);

    btCancel.setText("Cancel");
    gridBagConstraints = new java.awt.GridBagConstraints();
    gridBagConstraints.gridx = 2;
    gridBagConstraints.gridy = 2;
    pnDialog.add(btCancel, gridBagConstraints);

    return pnDialog;
    //Mommy someone is reading my code
}

private void btAcceptAction(java.awt.event.ActionEvent evt) {
    if (tfInput.getText().isEmpty()) {
        JOptionPane.showMessageDialog(pnDialog, "Input cannot be null", "Error", JOptionPane.ERROR_MESSAGE);
    }
}

private void btCancelAction(java.awt.event.ActionEvent evt) {
    JDialog topFrame = (JDialog) SwingUtilities.getWindowAncestor(pnDialog);
    topFrame.dispose();
}

public static void main(String[] args) {
    JDialog dialog = new JDialog();
    CustomInput tp = new CustomInput();
    dialog.add(tp.createPanel());
    dialog.setSize(new Dimension(200,200));
    dialog.setVisible(true);
}

}