java界面文本域_关于java图形界面开发下拉框和文本域以及其响应事件-Go语言中文社区...

package Test;

import java.awt.BorderLayout;

import java.awt.Color;

import java.awt.FlowLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.event.ItemEvent;

import java.awt.event.ItemListener;

import javax.swing.JButton;

import javax.swing.JComboBox;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JPanel;

import javax.swing.JTextArea;

public class b extends JFrame{

static b frm=new b();

static JComboBox combo;

static JTextArea ta=new JTextArea(20,40);

static JLabel be;

static String []color={"红色","蓝色","黄色"};

static JPanel p1,p2,p3;

static JButton btn1,btn2;

public static void main(String[] args){

frm.setLayout(new FlowLayout(FlowLayout.LEFT,20,20));

ta.setText("我是：");

combo =new JComboBox(color);

combo.setEditable(true);

combo.addItemListener(new MyItemListener());

combo.addActionListener(new MyActionListener());

p1=new JPanel();

be=new JLabel();

be.setText("Method:");

p1.add(be);

p1.add(combo);

btn1=new JButton("invoke");

btn2=new JButton("stop");

btn1.setSize(20, 10);

p1.add(btn1);

p1.add(btn2);

frm.add(p1);

//p1.setBounds(10, 10, 400, 40);

frm.setBounds(100, 100, 400, 500);

p2=new JPanel();

p2.add(ta);

p2.setBackground(Color.PINK);

p2.setSize(100, 100);

frm.add(p2);

frm.setSize(600, 600);

frm.setResizable(false);

frm.setBackground(Color.black);

frm.setVisible(true);

frm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

static class MyItemListener implements ItemListener{

@Override

public void itemStateChanged(ItemEvent e) {

// TODO Auto-generated method stub

JComboBox cb=(JComboBox)e.getSource();

String clr=(String)cb.getSelectedItem();

if(clr=="红色"){

ta.setBackground(Color.RED);

}else if(clr=="蓝色"){

ta.setBackground(Color.BLUE);

}else {

ta.setBackground(Color.YELLOW);

}

static class MyActionListener implements ActionListener{

@Override

public void actionPerformed(ActionEvent e) {

// TODO Auto-generated method stub

JComboBox cb=(JComboBox)e.getSource();

String s=(String)cb.getSelectedItem();

ta.setText(s+"n");

}

}

}

实现效果为：