java学习--GUI1

JFrame

JFrame类的常用操作方法

import java.awt.Color;
import javax.swing.JFrame;

public class JFrameDemo1 {
    public static void main(String[] args) {
        JFrame f = new JFrame("第一个Swing窗体");
        f.setSize(200, 100);
        f.setBackground(Color.WHITE);
        f.setLocation(300, 200);
        f.setVisible(true);
    }
}

在JFrame类中使用Dimension类设置窗体的大小，使用Point类显示组件的位置

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Point;
import javax.swing.JFrame;

public class JFrameDemo2 {
    public static void main(String[] args) {
        JFrame f = new JFrame("第一个Swing窗体");
        Dimension d = new Dimension();

        d.setSize(200, 100);
        f.setSize(d);
        f.setBackground(Color.WHITE);
        Point p = new Point(300,200);
        f.setLocation(p);
        f.setVisible(true);
    }
}

JLabel

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Point;
import javax.swing.JFrame;
import javax.swing.JLabel;

public class JLabelDemo1 {
    public static void main(String[] args) {
        JFrame frame = new JFrame("Welcome to leaf's blog");
        JLabel lab = new JLabel("leaf's blog",JLabel.CENTER);
        frame.add(lab);
        Dimension dim = new Dimension();
        dim.setSize(200, 100);
        frame.setSize(dim);
        frame.setBackground(Color.WHITE);
        Point p = new Point(300,200);
        frame.setLocation(p);
        frame.setVisible(true);
    }
}

更改JLabel的文字样式

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Point;
import java.awt.Font;
import javax.swing.JFrame;
import javax.swing.JLabel;

public class JLabelDemo2 {
    public static void main(String[] args) {
        JFrame frame = new JFrame("Welcome to leaf's blog");
        JLabel lab = new JLabel("leaf's blog",JLabel.CENTER);
        Font fnt = new Font("Serief", Font.ITALIC + Font.BOLD, 28);
        lab.setFont(fnt);
        lab.setForeground(Color.RED);
        frame.add(lab);
        Dimension dim = new Dimension();
        dim.setSize(200, 100);
        frame.setSize(dim);
        frame.setBackground(Color.WHITE);
        Point p = new Point(300,200);
        frame.setLocation(p);
        frame.setVisible(true);
    }
}

在JLabel中设置图片

方法一: 从图像取得字节数组，使用InputStream类完成操作

import java.awt.*;
import java.awt.Point;
import java.io.*;
import javax.swing.*;

public class JLabelDemo3 {
    public static void main(String[] args) {
        JFrame frame = new JFrame("Welcome to leaf's blog");
        String picPath = "E:" + File.separator + "1.jpg";
        File file = new File(picPath);
        InputStream input = null;
        byte[] b = new byte[(int)file.length()];

        try {
            input = new FileInputStream(file);
            input.read(b);
            input.close();
        } catch (Exception e) {
            e.getStackTrace();
        }

        Icon icon = new ImageIcon(b);
        JLabel lab = new JLabel("leaf's blog", icon, JLabel.CENTER);
        Font fnt = new Font("Serief", Font.ITALIC + Font.BOLD, 28);
        lab.setFont(fnt);
        lab.setForeground(Color.RED);
        lab.setBackground(Color.YELLOW);
        frame.add(lab);
        Dimension dim = new Dimension();
        dim.setSize(300, 160);
        frame.setSize(dim);
        frame.setBackground(Color.WHITE);
        Point p = new Point(300,200);
        frame.setLocation(p);
        frame.setVisible(true);

    }    
}

方法二：直接将图片的路径传递到ImageIcon的实例化中，并使用JLabel类中的ImageIcon的构造方法

import java.awt.*;
import java.io.*;
import javax.swing.*;

public class JLabelDemo4 {
    public static void main(String[] args) {
        JFrame frame = new JFrame("Welcome to leaf's blog");
        String picPath = "E:" + File.separator + "1.jpg";
        Icon icon = new ImageIcon(picPath);
        JLabel lab = new JLabel("leaf's blog", icon, JLabel.CENTER);
        Font fnt = new Font("Serief", Font.ITALIC + Font.BOLD, 28);
        lab.setFont(fnt);
        lab.setForeground(Color.RED);
        lab.setBackground(Color.YELLOW);
        frame.add(lab);
        frame.setSize(300,160);
        frame.setBackground(Color.WHITE);
        frame.setLocation(300,200);
        frame.setVisible(true);
    }
}

如果此时图像是从一个不确定输入流中而来，则要使用第一中方法；如果图像是从文件中而来，则使用第二中方法方便。

按钮组件JButton

import java.awt.*;
import javax.swing.*;

public class JButtonDemo1 {
    public static void main(String[] args) {
        JFrame frame = new JFrame("leaf");
        JButton jb = new JButton("Hello");
        Font fnt = new Font("Serief", Font.BOLD,28);
        jb.setFont(fnt);
        frame.add(jb);
        frame.setSize(300, 160);
        frame.setLocation(300, 200);
        frame.setVisible(true);
    }
}