JAVA的学习日记20-----GUI编程2

JavaGUI监听事件

事件监听

package com.JavaGUI.Demo02;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

public class TestActionEvent {
    public static void main(String[] args) {

        //按下按钮，可以触发一些事件
        Frame frame = new Frame("监听事件");

        Button button = new Button("Button按钮");

        //因为，addActionListener()需要一个ActionListener，所以我们需要构造一个ActionListener
        MyActionListener myActionListener = new MyActionListener();
        button.addActionListener(myActionListener);

        frame.add(button, BorderLayout.CENTER);
        frame.pack();


        frame.setBounds(50, 50, 400, 400);
        frame.setVisible(true);
        windowsClose(frame);


    }


    //关闭窗口事件
    private static void windowsClose(Frame frame){
        frame.addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
    }
}

//事件监听
class MyActionListener implements ActionListener {

    @Override
    public void actionPerformed(ActionEvent e) {
        System.out.println("aaaaa");
    }
}

多个按钮监听一个事件

package com.JavaGUI.Demo02;


import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class TestActionTwo {
    public static void main(String[] args) {

        Frame frame = new Frame("开始-结束");
        Button button1 = new Button("button1");
        Button button2 = new Button("button2");

        //可以显示的多个定义触发会返回的命令，如果不显示定义，则会走默认的值！
        //可以多个按钮只写一个监听类
        MyMonitor myMonitor = new MyMonitor();
        button1.addActionListener(myMonitor);
        button2.addActionListener(myMonitor);


        frame.add(button1, BorderLayout.NORTH);
        frame.add(button2, BorderLayout.SOUTH);


        frame.setBounds(50, 50, 400,400);
        frame.setVisible(true);
    }
}

class MyMonitor implements ActionListener{

    @Override
    public void actionPerformed(ActionEvent e) {
        //getActionCommand 获得按钮的信息
        System.out.println("按钮触发getActionCommand的作用为====>"+e.getActionCommand());
    }
}

文本框

package com.JavaGUI.Demo02;

import org.w3c.dom.Text;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class TestText01 {
    public static void main(String[] args) {
        //一个程序的main方法里面应该只有简单的启动代码！！！
        new MyFrame();
    }
}

class MyFrame extends Frame{

    public MyFrame(){
        //TextField表示文本框，不能换行，TextArea表示文本域，可换行
        TextField textField = new TextField();
        add(textField);

        //监听文本框输入的文字    enter接收
        MyActionListerTextField myActionListerTextField = new MyActionListerTextField();
        textField.addActionListener(myActionListerTextField);

        //设置替换编码---可以类似输入密码变成* 的这种、
        textField.setEchoChar('*');


        setVisible(true);
        pack();
    }
}

class MyActionListerTextField implements ActionListener {

    @Override
    public void actionPerformed(ActionEvent e) {
        TextField textField = (TextField) e.getSource();//获得一些资源，返回一个对象
        System.out.println(textField.getText());//获得输入文本框的内容
        textField.setText("");//清空文本框，不能使用 null【对象的用法】
    }
}

写一个简易计算

• 初始代码框架

package com.JavaGUI.Demo02;

import org.w3c.dom.Text;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class TestCala {
    public static void main(String[] args) {
        new Calculator();
    }
}

class Calculator extends Frame{
    public Calculator(){
        //三个文本框

        TextField textField1 = new TextField(10);//表示的是字符数
        TextField textField2 = new TextField(10);//表示的是字符数
        TextField textField3 = new TextField(20);//表示的是字符数

        //一个按钮
        Button button = new Button("=");
        //添加监听事件
        MyCalculatorLister myCalculatorLister = new MyCalculatorLister(textField1, textField2, textField3);
        button.addActionListener(myCalculatorLister);


        //一个标签
        Label label = new Label("+");


        //流式布局
        setLayout(new FlowLayout());
        add(textField1);
        add(label);
        add(textField2);
        add(button);
        add(textField3);

        pack();
        setVisible(true);

    }

}

class MyCalculatorLister implements ActionListener{
    //获取三个变量
    private TextField num1, num2, num3;
    public MyCalculatorLister(TextField num1, TextField num2,TextField num3){
        this.num1 = num1;
        this.num2 = num2;
        this.num3 = num3;
    }



    @Override
    public void actionPerformed(ActionEvent e) {
        //1.获得加数和被加数
        int n1 = Integer.parseInt(num1.getText());
        int n2 = Integer.parseInt(num2.getText());


        //2.将这个值进行+运算后，赋值给第三个数
        num3.setText(""+(n1+n2));


        //3.清除前两个数
        num1.setText("");
        num2.setText("");
    }
}

• 改写为面向对象的写法----用到了组合的概念【能用组合就尽量不使用多态】

package com.JavaGUI.Demo02;

import org.w3c.dom.Text;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class TestCala {
    public static void main(String[] args) {
        new Calculator().loadFrame();
    }
}

class Calculator extends Frame{

    //属性
    TextField num1, num2, num3;

    //方法
    public void loadFrame(){
        num1 = new TextField(10);
        num2 = new TextField(10);
        num3 = new TextField(10);
        Button button = new Button("=");
        Label label = new Label("+");

        //添加监听事件
        button.addActionListener(new MyCalculatorLister(this));


        //流式布局
        setLayout(new FlowLayout());
        add(num1);
        add(label);
        add(num2);
        add(button);
        add(num3);

        pack();
        setVisible(true);
    }

}

//监听器类
class MyCalculatorLister implements ActionListener{

    //获取计算器这个对象，在一个类中组合另外一个类
    Calculator calculator = null;

    //组合的概念
    public MyCalculatorLister(Calculator calculator){
        this.calculator = calculator;
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        //1.获得加数和被加数
        //2.将这个值进行+运算后，赋值给第三个数
        //3.清除前两个数
        int n1 = Integer.parseInt(calculator.num1.getText());
        int n2 = Integer.parseInt(calculator.num2.getText());
        calculator.num3.setText(""+(n1+n2));
        calculator.num1.setText("");
        calculator.num2.setText("");
    }
}

• 内部类

/*内部类*/
package com.JavaGUI.Demo02;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class TestCala {
    public static void main(String[] args) {
        new Calculator().loadFrame();
    }
}

class Calculator extends Frame{
    TextField num1, num2, num3;
    public void loadFrame(){
        num1 = new TextField(10);
        num2 = new TextField(10);
        num3 = new TextField(10);
        Button button = new Button("=");
        Label label = new Label("+");

        //添加监听事件
        button.addActionListener(new MyCalculatorLister());
        
        //流式布局
        setLayout(new FlowLayout());
        add(num1);
        add(label);
        add(num2);
        add(button);
        add(num3);

        pack();
        setVisible(true);
    }

    //监听器类
    private class MyCalculatorLister implements ActionListener{
        @Override
        public void actionPerformed(ActionEvent e) {

            int n1 = Integer.parseInt(num1.getText());
            int n2 = Integer.parseInt(num2.getText());
            num3.setText(""+(n1+n2));
            num1.setText("");
            num2.setText("");
        }
    }

}