J2ME字体的设置

1,Font类的特点:
①没有构造函数
②是final类型的类
③没有color属性,只有三性:.

2,特点决定用法:
不能被继承,不能被实例化.

3,关于字体的知识:
字体的形状-----face,字体的风格----Style,字体的大小---size

4,J2ME提供的字体:

形状:
FACE_MONOSPACE---等宽字体
FACE_PROPORTIONAL----均衡字体
FACE_SYSTEM----系统字体

风格:
STYLE_BOLD-----粗体
STYLE_ITALIC---斜体
STYLE_PLAIN----普通
STYLE_UNDERLINED----下画线
注意:风格可以组合.如: STYLE_BOLD| STYLE_ITALIC 两两组合,或者三者组合STYLE_UNDERLINED |STYLE_BOLD| STYLE_ITALIC

大小:
SIZE_LARGE--- 16
SIZE_MEDIUM----0
SIZE_SMALL-----8
       
5,color:

由于J2ME技术比较简单，所以没有实现专门的颜色类，而只是使用RGB的概念来代表颜色。这里简单介绍一下RGB的概念，颜色是由红(Red)、绿(Green)、蓝(Blue)三原色组成的，所以可以使用这三个颜色的组合来代表一种具体的颜色，其中R、G、B的每个数值都位于0-255之间。在表达颜色的时候，即可以使用三个数字来表达，也可以使用一个格式如0X00RRGGBB这样格式的十六进制来表达，下面是常见颜色的表达形式：
红色：(255,0,0)或0x00FF0000 
绿色：(0,255,0)或0x0000FF00 
蓝色：(255,255,255)或0x00FFFFFF
可以使用setColor(int red,int green,int blue)或者setColor(int RGB)来设置字体的颜色,用getColor()来获取字体的颜色

6.用法:

①在Graphics类中的运用:

import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;
import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Font;
import javax.microedition.lcdui.Display;

public class GraphicsTest extends MIDlet {
    private GraphicsTestCanvas showCanvas;
    public GraphicsTest() {
        showCanvas = new GraphicsTestCanvas();
    }

    protected void startApp() throws MIDletStateChangeException {
        Display.getDisplay(this).setCurrent(showCanvas);
    }

    protected void pauseApp() {
    }

    protected void destroyApp(boolean _boolean) throws
            MIDletStateChangeException {
    }

    class GraphicsTestCanvas extends Canvas {
        private Font myFont;
        public GraphicsTestCanvas() {
            //设置字体
            myFont = Font.getFont(Font.FACE_SYSTEM,
                                  Font.STYLE_UNDERLINED | Font.STYLE_BOLD |
                                  Font.STYLE_ITALIC, Font.SIZE_LARGE);
        }

        private final String showMessage = "kuikui,你好!";
        protected void paint(Graphics g) {
            g.setFont(myFont);
            g.drawString(showMessage, this.getWidth() / 2, this.getHeight() / 2,
                         Graphics.TOP | Graphics.LEFT);
        }
    }
}

import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;

public class DrawCanvas extends MIDlet implements CommandListener {
    private Command exitCommand;
    private HCanvas sg;
    public DrawCanvas() {
        exitCommand = new Command("Exit", Command.EXIT, 1);
        sg = new HCanvas();
        sg.addCommand(exitCommand);
        sg.setCommandListener(this);
        Display.getDisplay(this).setCurrent(sg);
    }

    protected void startApp() {
    }

    protected void pauseApp() {
    }

    protected void destroyApp(boolean unconditional) {
    }

    public void commandAction(Command c, Displayable d) {
        if (c == exitCommand) {
            destroyApp(false);
            notifyDestroyed();
        }
    }
}


class HCanvas extends Canvas implements Runnable {
    private String str = new String("Hello,LinuxFans！");
    private int[] adjustHight = new int[] {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                                0, 0, 0, 0, 0, 1, 2, 3, 4, 4, 3, 2, 1, 1, 2, 3,
                                3, 4, 4, 3, 2, 1, };
    boolean bStart = true;
    private int k = str.length();
    public HCanvas() {
        new Thread(this).start();
    }

    protected void paint(Graphics g) {
        g.setColor(0x00ffffff);
        g.fillRect(0, 0, getWidth(), getHeight());
        g.setColor(0x00000000);
        for (int i = 0; i < str.length(); i++) {
            g.drawString(str.substring(i, i + 1), 20 + i * 7,
                         10 - adjustHight[k - i], 0);
            g.drawString(str.substring(i, i + 1), 21 + i * 7,
                         11 - adjustHight[k - i], 0); //加重字体7是字体宽度
        }
    }

    public void run() {
        while (bStart) {
            try {
                repaint();
                Thread.sleep(70);
                k++;
                if (k > (adjustHight.length - 1)) {
                    k = str.length();
                }
            } catch (InterruptedException e) {}
        }
    }
}