在java中,我一直在尝试创建一个可以接受其他带有滚动条的面板的面板。
我尝试使用网格布局,这工作得很好,除了如果我只添加几个面板,它会增长这些面板以适应父面板的大小。
我尝试使用 flowlayout,但这使得面板水平流动,因为有滚动条。
我该如何制作才能将面板添加到从顶部开始的父面板,并使它们始终具有相同的尺寸(或其首选尺寸)。
此外,当我在事件发生后将面板添加到父面板时,直到我移动或调整表单大小后,它们才会出现。我该如何让它重新喷漆?对其调用 repaint() 不起作用。
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
/** This lays out components in a column that is constrained to the
top of an area, like the entries in a list or table. It uses a GridLayout
for the main components, thus ensuring they are each of the same size.
For variable height components, a BoxLayout would be better. */
class ConstrainedGrid {
ConstrainedGrid() {
final JPanel gui = new JPanel(new BorderLayout(5,5));
gui.setBorder(new EmptyBorder(3,3,3,3));
gui.setBackground(Color.red);
JPanel scrollPanel = new JPanel(new BorderLayout(2,2));
scrollPanel.setBackground(Color.green);
scrollPanel.add(new JLabel("Center"), BorderLayout.CENTER);
gui.add(new JScrollPane(scrollPanel), BorderLayout.CENTER);
final JPanel componentPanel = new JPanel(new GridLayout(0,1,3,3));
componentPanel.setBackground(Color.orange);
scrollPanel.add(componentPanel, BorderLayout.NORTH);
JButton add = new JButton("Add");
gui.add(add, BorderLayout.NORTH);
add.addActionListener( new ActionListener() {
public void actionPerformed(ActionEvent ae) {
componentPanel.add(new JTextField());
gui.validate();
}
});
Dimension d = gui.getPreferredSize();
d = new Dimension(d.width, d.height+100);
gui.setPreferredSize(d);
JOptionPane.showMessageDialog(null, gui);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
ConstrainedGrid cg = new ConstrainedGrid();
}
});
}
}
本文内容由网友自发贡献,版权归原作者所有,本站不承担相应法律责任。如您发现有涉嫌抄袭侵权的内容,请联系:hwhale#tublm.com(使用前将#替换为@)