Loops [JAVA无限循环,同时需要填充空字段
我一直在尝试用while循环显示消息对话框来处理程序中可能出现的错误,对话框上写着“填充空格”,但它是无限的。简单地说,当我尝试添加某些内容(例如联系人)时,有些字段必须全部填充,我如何确保这一点 这是我的代码,可以很好地查找未填充的字段,但它可以无限运行Loops [JAVA无限循环,同时需要填充空字段,loops,while-loop,field,fill,infinite,Loops,While Loop,Field,Fill,Infinite,我一直在尝试用while循环显示消息对话框来处理程序中可能出现的错误,对话框上写着“填充空格”,但它是无限的。简单地说,当我尝试添加某些内容(例如联系人)时,有些字段必须全部填充,我如何确保这一点 这是我的代码,可以很好地查找未填充的字段,但它可以无限运行 public void createContact(){ final JFrame addContact = new JFrame("Add Contact"); addContact.setSize(400,300)
public void createContact(){
final JFrame addContact = new JFrame("Add Contact");
addContact.setSize(400,300);
addContact.setLayout(new BorderLayout());
addContact.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
JPanel info = new JPanel(new GridLayout(6,2));
JButton add = new JButton("Add");
JLabel title = new JLabel("Title: ");
JLabel firstname = new JLabel("FIRST NAME: ");
JLabel lastname = new JLabel("LAST NAME: ");
JLabel adress = new JLabel("Adress: ");
JLabel email = new JLabel("Email: ");
JLabel company = new JLabel("Company Name: ");
final JTextField title1 = new JTextField(20);
final JTextField firstname1 = new JTextField(20);
final JTextField lastname1 = new JTextField(20);
final JTextField adress1 = new JTextField(20);
final JTextField email1 = new JTextField(20);
final JTextField company1 = new JTextField(20);
info.add(title);
info.add(title1);
info.add(firstname);
info.add(firstname1);
info.add(lastname);
info.add(lastname1);
info.add(adress);
info.add(adress1);
info.add(email);
info.add(email1);
info.add(company);
info.add(company1);
addContact.add(info,BorderLayout.NORTH);
addContact.add(add,BorderLayout.SOUTH);
add.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent ae){
while(title1.getText().length() == 0 || firstname1.getText().length() == 0 || firstname1.getText().length() == 0 || adress1.getText().length() == 0 || email1.getText().length() == 0 ||company1.getText().length() ==0){
JOptionPane.showMessageDialog(null,"Please fill the empty fields.");
}
Contact newContact = new Contact(title1.getText(),firstname1.getText(),lastname1.getText(),adress1.getText(),email1.getText(),company1.getText());
contactList.add(newContact);
JOptionPane.showMessageDialog(null,"Contact has been added successfuly!");
addContact.setVisible(false);
}
});
addContact.pack();
addContact.setVisible(true);
}
由于它位于while块中,因此它将始终连续运行(因为条件始终满足)。但您不能修改任何内容,因为一旦您确认消息,我将再次弹出。请改为使用“if”:
add.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent ae){
if (title1.getText().length() == 0 || firstname1.getText().length() == 0 || firstname1.getText().length() == 0 || adress1.getText().length() == 0 || email1.getText().length() == 0 ||company1.getText().length() ==0){
JOptionPane.showMessageDialog(null,"Please fill the empty fields.");
} else {
Contact newContact = new Contact(title1.getText(),firstname1.getText(),lastname1.getText(),adress1.getText(),email1.getText(),company1.getText());
contactList.add(newContact);
JOptionPane.showMessageDialog(null,"Contact has been added successfuly!");
addContact.setVisible(false);
}
}
}
哇,那很简单!我还没想过,现在看起来很傻哈哈!谢谢!