JTextField Fixed Height

问题:

How do I get the JTextField to have a fixed height when the Frame is maximized? I want it to look sort of similar to the Skype application on Ubuntu.

private JTextField username;
private JPasswordField password;
private JLabel usernamelabel;
private JLabel passwordlabel;
public LoginPanel(){


    setSize(200,200);
    setLayout(new GridLayout(4,4));
    setBackground(new Color(85,153,187));
    setBorder(BorderFactory.createEmptyBorder(70, 70, 70, 70));
    username = new JTextField();
    password = new JPasswordField();
    usernamelabel= new JLabel("Username");
    passwordlabel= new JLabel("Password");
    username.setBounds(5, 5, 100, 100);
    username.setPreferredSize(new Dimension(80,20));
    password.setPreferredSize(new Dimension(80,20));
    add(usernamelabel);
    add(username);
    add(passwordlabel);
    add(password);

回答1:

Don't use a layout other than GridLayout or put the text field in another panel that has a FlowLayout that sits inside of your GridLayout.

回答2:

I think this solves your problem.

import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.GridLayout;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class Main { 

/**
 * @param args
 */
public static void main(String[] args) {
    JFrame failFrame = new JFrame();
    JPanel mainPanel = new JPanel();
    mainPanel.setLayout(new GridLayout(0, 4));

    JPanel leftTextFieldPanel = new JPanel();
    leftTextFieldPanel.setLayout(new FlowLayout());        
    JPanel rightTextFieldPanel = new JPanel();
    rightTextFieldPanel.setLayout(new FlowLayout());

    JTextField leftTextField = new JTextField();
    leftTextField.setPreferredSize(new Dimension(150,20));              
    JTextField rightTextField = new JTextField();
    rightTextField.setPreferredSize(new Dimension(150,20));

    leftTextFieldPanel.add(leftTextField);
    mainPanel.add(leftTextFieldPanel);

    rightTextFieldPanel.add(rightTextField);
    mainPanel.add(rightTextFieldPanel);

    mainPanel.add(new JPanel());
    mainPanel.add(rightTextFieldPanel);
    mainPanel.add(new JPanel());

    failFrame.add(mainPanel);
    failFrame.setSize(600, 400);
    failFrame.setLocationRelativeTo(null);
    failFrame.setVisible(true);
}
}

I used nested Layouts. On the Top is your GridLayout and the textfields are in a FlowLayout which are added on the gridLayout panel. So the textfields are no longer stretched.

回答3:

You can refer to here.

The setMaximumSize method can be found in JComponent and the JTextField gets to use this method from JComponent.

EDIT: However, it seems its not a good practice to hardcode the size of the JTextField particularly when you are running it on multiple platforms as you may face issues with the font-size.

回答4:

Thanks for all the help guys, hope this helps out others in the future. I got the visual look that I was looking for.

private JTextField username;
private JPasswordField password;
private JPanel [] login = {new JPanel(), new JPanel()};
private JLabel usernamelabel;
private JLabel passwordlabel;

public LoginPanel(){

    setSize(200,200);
    setBackground(new Color(85,153,187));
    setBorder(BorderFactory.createEmptyBorder(70, 70, 70, 70));
    username = new JTextField();
    password = new JPasswordField();
    usernamelabel= new JLabel("Username");
    passwordlabel= new JLabel("Password");
    login[0].add(usernamelabel);
    login[0].add(username);
    login[1].add(passwordlabel);
    login[1].add(password);
    for(JPanel p : login){
        p.setBackground(new Color(85,153,187));
        this.add(p);
    }
    username.setBounds(5, 5, 100, 100);
    username.setPreferredSize(new Dimension(120,20));
    password.setPreferredSize(new Dimension(120,20));

} 

回答5:

In a pinch, doing

tf.setMaximumSize(tf.getMinimumSize())

will keep it constant size and platform neutral.