Java-day16 study notes

Others 2021-01-28 17:36:55 views: null

day15 review

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Java-day16 study notes

One, GUI

AWT（Abstract Window ToolKit）包括了很多类和接口，用来进行Java Application（Java应用）的GUI（Graphics User Interface）图形用户接口编程。

GUI包括了像按钮、文本框、下拉列表等都是由来实现的
AWT所包括的类和接口在java.awt包下
AWT包含的类中有两个核心的类：Component和Container

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Component是awt中最基本的一个类，Component中有两个使用最多的类：Frame、Panel

Frame是一个窗体，是能自由停泊的顶级窗口（可以直接显示windows上）
Panel是一个容器，能装其它的Component组件（包括它自己）（不能直接显示在windows操作系统上）

注意：Panel不能直接显示在windows操作系统上，但是可以将Panel添加到Frame中，然后通过Frame显示出来

Two, Frame form

It is a top-level window that can be parked freely (can be directly displayed on windows)

2.1 Construction method

Frame()    				构造一个最初不可见的 Frame 新实例（）
Frame(String title)     构造一个新的、最初不可见的、具有指定标题的 Frame 对象

2.2 Common methods

void setVisible(boolean b)				根据参数 b 的值显示或隐藏此 Window
void setTitle(String title)  			将此窗体的标题设置为指定的字符串
void setSize(int width,int height)   	调整组件的大小，使其宽度为 width，高度为 height
    
void setLocation(int x, int y)			将组件移到新位置
    参数：
    x - 父级坐标空间中新位置左上角的 x 坐标
	y - 父级坐标空间中新位置左上角的 y 坐标
    
public void setBounds(int x, int y, int width, int height)  移动组件并调整其大小  
    参数：
    x - 组件的新 x 坐标
    y - 组件的新 y 坐标
    width - 组件的新 width
    height - 组件的新 height.
    
void setResizable(boolean resizable) 	设置此窗体是否可由用户调整大小 
    
void setBackground(Color c)				设置组件的背景色

import java.awt.*;

public class Demo {
    
    

    public static void main(String[] args) {
    
    

        //无参构造
//        Frame frame = new Frame();
//        frame.setTitle("haha");

        //带参构造
        Frame frame = new Frame("第一个窗口");

//        frame.setSize(400, 300);
//        frame.setLocation(100, 200);

        frame.setBounds(300, 300, 500, 500);

        frame.setResizable(false);
        frame.setVisible(true);
    }

}

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import java.awt.*;

class MyFrame extends Frame {
    
    

    static int i = 0;
    public MyFrame(int x, int y, int width, int height, Color color) {
    
    

        super("窗口" + (++i));

        setLocation(x, y);
        setSize(width, height);
        setBackground(color);

        setVisible(true);
    }

}

public class Test {
    
    

    public static void main(String[] args) {
    
    

        new MyFrame(200, 200, 300, 300, Color.BLUE);
        new MyFrame(500, 200, 300, 300, Color.RED);
        new MyFrame(200, 500, 300, 300, Color.GREEN);
        new MyFrame(500, 500, 300, 300, Color.PINK);
    }
}

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Three, Panel panel

Panel can be installed with other Component components, but it cannot be displayed directly

3.1 Construction method

Panel()       					使用默认的布局管理器创建新面板
Panel(LayoutManager layout) 	创建具有指定布局管理器的新面板

3.2 Common methods

add(Component comp)             将其它组件添加到Panel中

import java.awt.*;

public class Demo2 {
    
    

    public static void main(String[] args) {
    
    

        //1. 创建一个窗体
        Frame frame = new Frame("Panel测试！");

        //2. 创建一个Panel面板，用来装其它组件，比如按钮
        Panel panel = new Panel();

        Button button = new Button("click me！");

        //3. 将创建好的按钮通过add方法添加到Panel面板中
        panel.add(button);

        //4. 将Panel面板添加到Frame窗体中
        frame.add(panel);

        //5. 设置窗体的位置及大小
        frame.setBounds(300, 300, 500, 300);

        //6. 显示
        frame.setVisible(true);

    }
}

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Four, layout management

If the coordinates are fixed, the overall layout of the page will be disrupted after being stretched. In order to solve this situation, Java provides layout management.

The method of setting the layout is: setLayout(LayoutManager lm)

All classes under Container have default layout management.

Common ones are: FlowLayout, BorderLayout, GridLayout

4.1 FlowLayout flow layout

If one line can fit, then put it on one line; if one line can't fit, then it will switch to the next line and place the remaining content

FlowLayout is the default layout of Panel

Common settings are:

​ FlowLayout.CENTER centered

​ FlowLayout.LEFT left

​ FlowLayout.RIGHT right

Construction method

FlowLayout() Constructs a new FlowLayout, which is center-aligned, and the default horizontal and vertical gap is 5 units.
FlowLayout(int align) Constructs a new FlowLayout with a specified alignment. The default horizontal and vertical gap is 5 units
FlowLayout(int align, int hgap, int vgap) Create a new flow layout manager with specified alignment and specified horizontal and vertical gaps

import java.awt.*;

public class Demo {
    
    

    public static void main(String[] args) {
    
    

        //1. 创建窗体，用来装Panel并展示
        Frame frame = new Frame("流布局");

        //2. 创建Panel，用来装内容，比如按钮
        Panel panel = new Panel();
        //3. 设置Panel的布局为靠左流布局
//        panel.setLayout(new FlowLayout(FlowLayout.CENTER));
        panel.setLayout(new FlowLayout(2));   //等效于FlowLayout.RIGHT;
//        panel.setLayout(new FlowLayout(FlowLayout.CENTER, 20, 30));

        Button b = new Button("bt1");
        Button b2 = new Button("bt2");
        Button b3 = new Button("bt3");
        Button b4 = new Button("bt4");
        Button b5 = new Button("bt5");

        //4. 将按钮添加到Panel中
        panel.add(b);
        panel.add(b2);
        panel.add(b3);
        panel.add(b4);
        panel.add(b5);

        //5. 将Panel添加到Frame中
        frame.add(panel);

        //6. 设置窗体的大小并展示
        frame.setBounds(200, 200, 500, 300);

        frame.setVisible(true);

    }
}

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4.2 BorderLayout Border layout

Divided into five directions: east, west, south, north and middle

BorderLaout is the default layout of Frame

Construction method

BorderLayout() 						构造一个组件之间没有间距的新边框布局。 
BorderLayout(int hgap, int vgap) 	构造一个具有指定组件间距的边框布局 

import java.awt.*;

public class Demo2 {
    
    

    public static void main(String[] args) {
    
    

        //1. 创建窗体
        Frame frame = new Frame("边框布局");

        //2. 创建5个按钮
        Button b1 = new Button("bt1");
        Button b2 = new Button("bt2");
        Button b3 = new Button("bt3");
        Button b4 = new Button("bt4");
        Button b5 = new Button("bt5");

        //3. 将按钮添加到窗体中
//        frame.add(b1, "North");
//        frame.add(b2, "South");
//        frame.add(b3, "West");
//        frame.add(b4, "East");
//        frame.add(b5, "Center");

        frame.add(b1, BorderLayout.NORTH);
        frame.add(b2, BorderLayout.SOUTH);
        frame.add(b3, BorderLayout.WEST);
        frame.add(b4, BorderLayout.EAST);
        frame.add(b5, BorderLayout.CENTER);

        //4. 设置窗体大小并显示
        frame.setBounds(200, 200, 500, 500);
        frame.setVisible(true);

    }
}

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4.3 GridLayout table layout

GridLayout() 						创建具有默认值的网格布局，即每个组件占据一行一列。 
GridLayout(int rows, int cols)  	创建具有指定行数和列数的网格布局。 
GridLayout(int rows, int cols, int hgap, int vgap)   创建具有指定行数和列数的网格布局 

import java.awt.*;

public class Demo3 {
    
    

    public static void main(String[] args) {
    
    

        //1. 创建窗体
        Frame frame = new Frame("表格布局");

        //2. 创建5个按钮
        Button b1 = new Button("bt1");
        Button b2 = new Button("bt2");
        Button b3 = new Button("bt3");
        Button b4 = new Button("bt4");
        Button b5 = new Button("bt5");

        //3. 设置窗体的布局
        frame.setLayout(new GridLayout(2, 3));

        //4. 将按钮添加到窗体中
        frame.add(b1);
        frame.add(b2);
        frame.add(b3);
        frame.add(b4);
        frame.add(b5);

        //5. 设置窗体大小并显示
        frame.setBounds(200, 200, 300, 500);
        frame.setVisible(true);

    }
}

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Five, event monitoring

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注意：只有将监听器绑定到了监听源对象上，监听器才能监听事件源对象发送的事件信息，并进行相应的处理

5.1 Mouse event monitoring

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

/*
    实现监听器对象
*/
class MyMonitor implements ActionListener {
    
    

    @Override
    public void actionPerformed(ActionEvent e) {
    
    

        System.out.println("你扒拉我干啥！");
    }
}

public class Demo {
    
    

    public static void main(String[] args) {
    
    

        //1. 创建窗体
        Frame frame = new Frame("鼠标事件监听");

        //2. 创建按钮
        Button button = new Button("click me!");
        //3. 将按钮添加到窗体上
        frame.add(button);

        //创建监听器对象
        MyMonitor monitor = new MyMonitor();

        //将监听器对象绑定到按钮上
        button.addActionListener(monitor);

        //4. 设置窗体大小并显示
        frame.setBounds(200, 200, 300, 300);
        frame.setVisible(true);

    }

}

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5.2 Window event monitoring

close the window

import java.awt.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;

public class Demo2 {
    
    

    public static void main(String[] args) {
    
    

        Frame frame = new Frame("窗体关闭");

        //关闭窗体
        frame.addWindowListener(new WindowAdapter() {
    
    
            @Override
            public void windowClosing(WindowEvent e) {
    
    
                System.exit(0);
            }
        });

        frame.setSize(100, 100);
        frame.setVisible(true);
    }
}

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Origin blog.csdn.net/ChangeNone/article/details/112846794
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