关于updateui

[jessewizard]

帮忙看个小程序，先画一个JCheckBox，如果JCheckBox被选中，就动态地画个JButton到jframe里面，画完调用updateui为什么没效果？要调整下窗口大小才能显出来，另附上另一个程序，调用updateui就可以

import java.awt.Container;
import java.awt.Frame;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JColorChooser;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Text extends JFrame{
	JCheckBox a = new JCheckBox("1");
	JColorChooser j = new JColorChooser();
	Frame f = new Frame("text");
	JPanel p= new JPanel(new GridLayout(4,1));

	public void lantchFrame(){
		f.addWindowListener(new WindowAdapter(){
			public void windowClosing(WindowEvent e){
				System.exit(0);
			}
		});
		p.add(a);
		f.add(p);
		a.addActionListener(new MyListener());
		f.pack();
		f.setSize(320,240);
		f.setVisible(true);
	}
	class MyListener implements ActionListener {
		public void actionPerformed(ActionEvent e) {
			if(a.isSelected()){
				JButton jb3 = new JButton("jb3");
				p.add(jb3);
				p.updateUI();
			}
		}
	}
	public static void main(String [] args){
		Text t=new Text();
		t.lantchFrame();
	}

}

//这是我从网上找的，测试可用，不过我找不出上面程序哪里错了- -
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

public class Ss extends JFrame {

    Container con = this.getContentPane();
    JButton jb1 = new JButton("jb1");
    JButton jb2 = new JButton("jb2");
    JLabel jl1 = new JLabel("jl1");
    FlowLayout gly = new FlowLayout();
    JPanel jp = new JPanel(gly);

    public Ss() {
        con.add(jp);
        jp.add(jb1);
        jp.add(jb2);
        MyListener ml = new MyListener();
        jb1.addMouseListener(ml);
        this.setSize(300, 200);
        this.setVisible(true);
    }

    private class MyListener extends MouseAdapter {
    	public void mouseClicked(MouseEvent e) {
           try {
                JButton jb3 = new JButton("jb3");
                jp.add(jb3);
                jp.updateUI();//可以正常显示
           } catch (Exception ex) {
                ex.printStackTrace();
            }
        }
    }

    public static void main(String s[]) {
        Ss sss = new Ss();
        sss.setVisible(true);
    }
}

[jessewizard]

没人回答吗- -

[buzaibeishang4617016]

           try {
                JButton jb3 = new JButton("jb3");
                jp.add(jb3);
                jp.updateUI();//可以正常显示
           } catch (Exception ex) {
                ex.printStackTrace();
            }

        public void actionPerformed(ActionEvent e) {
            if(a.isSelected()){
                JButton jb3 = new JButton("jb3");
                p.add(jb3);
                p.updateUI();
            }
        }

跟楼主的if()循环不协调；if()循环只做一次

[Mybeautiful]

是个布局的问题, 研究哈GridLayout与FlowLayout的区别

[yueguangkai001]

Frame f = new Frame("text");这句 你能够换成JFrame么?
JFrame 跟Frame有很大的区别的,别混用

[jessewizard]

[Quote=引用 4 楼 yueguangkai001 的回复:]
Frame f = new Frame("text");这句 你能够换成JFrame么?
JFrame 跟Frame有很大的区别的,别混用
[/Quote]
果然是JFrame的问题，第一个程序本来是自己写的，第二个是后来找百度来的，所以有些差别没注意，谢谢你