我正在尝试使用FlowLayout创建一个内部插入两个JPanel的JFrame。我将帧初始化在一个单独的文件中,但是这就是所谓的
public class FlowInFlow extends JFrame
{
public FlowInFlow() {
setLayout(new FlowLayout());
JPanel panel1 = new JPanel(new FlowLayout(FlowLayout.LEFT));
panel1.setBackground(Color.RED);
JPanel panel2 = new JPanel(new FlowLayout(FlowLayout.RIGHT));
panel2.setBackground(Color.BLUE);
}
}
编辑:运行此程序时,我只得到一个空白框,当我需要两个框并排放置时
最佳答案
正如我已经说过的,JPanel
的默认首选大小是0x0 ...
这意味着,当您将其添加到FlowLayout
之类的布局中时,将使用首选大小,它将显示...好吧...它将不会
public class TestFlowLayout {
public static void main(String[] args) {
new TestFlowLayout();
}
public TestFlowLayout() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
JPanel master = new JPanel(new FlowLayout(FlowLayout.LEFT));
JPanel left = new JPanel();
left.setBackground(Color.RED);
left.add(new JLabel("Lefty"));
JPanel right = new JPanel();
right.setBackground(Color.BLUE);
right.add(new JLabel("Righty"));
master.add(left);
master.add(right);
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(master);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
}