手动创建表单

Question

我正在尝试使用代码而不是设计器手动创建表单，我已经使用设计器创建了。

这是迄今为止我想出的手动代码，但我在并排对齐标签和文本字段时遇到问题

mport java.awt.*;
import javax.swing.*;
/**
 *
 * @author jackandjill
 */
public class summinup_copy extends JFrame
{
    private JLabel lblTitle, lblOctal, lblDecimal, lblMessage ;

private JTextField txtOctal, txtDecimal;

private JButton calculate_btn;




public  summinup_copy()       

{

JPanel panel = (JPanel)this.getContentPane();

panel.setLayout(new BorderLayout());

JPanel panCentre = new JPanel();

panCentre.setLayout(new GridLayout(3,3));

lblTitle = new JLabel("Area of Triangle");

lblTitle.setFont(new Font("Arial", 1, 20));

lblTitle.setHorizontalAlignment(JLabel.CENTER);

lblOctal = new JLabel("Octal");

lblOctal.setHorizontalAlignment(JLabel.CENTER) ;

//lblDecimal = new JLabel("Decimal");
//
//lblDecimal.setHorizontalAlignment(JLabel.CENTER);

lblMessage = new JLabel("Result will be displayed here");

lblMessage.setForeground(Color.red);

lblMessage.setHorizontalAlignment(JLabel.CENTER);

txtOctal = new JTextField("0", 5);

txtOctal.setHorizontalAlignment(JLabel.CENTER); 
//txtDecimal = new JTextField("0", 5);
//
//txtDecimal.setHorizontalAlignment(JLabel.CENTER);

calculate_btn = new JButton("Calculate Area");



//AHandlerClass aListener = new AHandlerClass() ;

//btnOtoD.addActionListener(aListener);

//btnDtoO.addActionListener(aListener);

panCentre.add(lblOctal);

//panCentre.add(lblDecimal);

panCentre.add(txtOctal);

//panCentre.add(txtDecimal);

panCentre.add(calculate_btn);

//panCentre.add(btnDtoO);

panel.add(lblTitle, BorderLayout.NORTH);

panel.add(lblMessage,BorderLayout.SOUTH);


panel.add(panCentre, BorderLayout.CENTER);

}

public static void main(String args[]) {

summinup_copy myGui = new summinup_copy();

myGui.setTitle("Bharath");

myGui.setSize(400, 200);

myGui.setVisible(true);
}

}

Answer 1

正如您已经知道的那样，您必须在手动编写 Swing GUI 时使用 LayoutManagers。这里有一些链接可以帮助您确定哪个 LayoutManager 适合给定的外观：

http://docs.oracle.com/javase/tutorial/uiswing/layout/visual.html

http://docs.oracle.com/javase/tutorial/uiswing/layout/using.html

为了在 JTextField 或其他组件旁边放置 JLabel，我通常使用 GridLayout 或 GridBagLayout。我发现要让组件看起来像我想要的那样需要大量的试验和错误。通常，您必须嵌入多层 JPanel 才能使其恰到好处。