J2ME游戏开发之字符串的绘制

package com.sliw.graphics;

import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.Font;
import javax.microedition.lcdui.Graphics;


/**
 * 
 * @author 章伟
 *
 *
 
   1) face 为字体的外观，J2ME中提供了如下几种face：
       Font.FACE_SYSTEN
       Font.FACE_MONOSPACE
       Font.FACE_PROPORTIONAL
    
    2) style 为字体的风格，J2ME中提供了如下几种style：
       Font.STYLE_PLAIN
       Font.STYLE_BOLD
       Font.STYLE_ITALIC
       Font.STYLE_UNDERLINED
    其中，后三种可以混合使用，例：粗体加斜体的写法
    Font.getFont(Font.FACE_SYSTEM, Font.STYLE_BOLD|Font.STYLE_ITALIC, Font.SIZE_SMALL);
    
    3) size 为字体的大小，J2ME中提供了如下几种size：
       Font.SIZE_SMALL
       Font.SIZE_MEDIUM
       Font.SIZE_LARGE
 */
public class StringCanvas extends Canvas{

    private int topY = 20;
    private int left = 10;
    private String s = "hello zhangweia!";
    
    protected void paint(Graphics g) {
        // TODO Auto-generated method stub
        clear(g);
        
        drawString(g);
    }
    
    
    public void drawString(Graphics g){
        
        Font font ;
        // getFont(int face, int style, int size)
        font = Font.getFont(Font.FACE_SYSTEM, Font.STYLE_BOLD, Font.SIZE_LARGE);
        
        g.setFont(font);
        g.setColor(255,0,0);
        g.drawString(s, left, topY, Graphics.LEFT | Graphics.TOP);
        
        System.out.println("字符高度=" + font.getHeight() + "字符宽度=" + font.stringWidth(s));
        
        topY = topY + font.getHeight() + 20;
        g.drawSubstring(s, 0, 5, left, topY, Graphics.LEFT | Graphics.TOP);
        
        char c = 'a';
        topY = topY + 20;
        g.drawChar(c, left, topY, Graphics.LEFT | Graphics.TOP);
    }
    
    public void drawChar(){
        
    }
    
    private void clear(Graphics g){
        g.setColor(255,255,255);
        g.fillRect(0, 0, getWidth(), getHeight());
    }

}