drawgraphics.java

在eclipse环境下

import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;

public class DrawGraphics extends MIDlet implements CommandListener {
    Display display;
    
    //画布
    GraphicCanvas gc;
    
    //画线
    Command cmdLine = new Command("Line", Command.SCREEN, 1); 
    //画没有填充的矩形
    Command cmdRect = new Command("Rectangle", Command.SCREEN, 1); 
    //画没有填充的圆角矩形
    Command cmdRoundRect = new Command("Round Rectangle", Command.SCREEN, 1); 
    //画没有填充的弧线
    Command cmdArc = new Command("Arc", Command.SCREEN, 1); 
    
    //画有填充的矩形
    Command cmdFillRect = new Command("Fill Rectangle", Command.SCREEN, 1);  
    //画有填充的圆角矩形
    Command cmdFillRoundRect = new Command("Fill Round Rectangle", Command.SCREEN, 1); 
    //画有填充的弧线
    Command cmdFillArc = new Command("Fill Arc", Command.SCREEN, 1);
    //画有填充的弧线
    Command cmdFillTriangle = new Command("Fill Triangle", Command.SCREEN, 1);

    public DrawGraphics() {
        super();
        //创建画布对象实例
        gc = new GraphicCanvas();
        gc.addCommand(cmdLine);
        gc.addCommand(cmdRect);
        gc.addCommand(cmdRoundRect);
        gc.addCommand(cmdArc);
        gc.addCommand(cmdFillRect);
        gc.addCommand(cmdFillRoundRect);
        gc.addCommand(cmdFillArc);
        gc.addCommand(cmdFillTriangle);
        gc.setCommandListener(this);
    }

    protected void startApp() throws MIDletStateChangeException {
        //获得当前MIDlet的Display对象
        display = Display.getDisplay(this); 
        //设置GraphicCanvas对象为当前显示对象
        display.setCurrent(gc);
    }

    protected void pauseApp() {
        // TODO Auto-generated method stub

    }

    protected void destroyApp(boolean arg0) 
        throws MIDletStateChangeException {
        // TODO Auto-generated method stub

    }
    
    /**
     * 处理命令按钮事件
     */
    public void commandAction(Command c, Displayable d) {
        if (c == this.cmdLine) {
            gc.draw(GraphicCanvas.LINE);
        } else if (c == cmdRect) {
            gc.draw(GraphicCanvas.RECTANGL_NO_FILL);
        } else if (c == cmdRoundRect) {
            gc.draw(GraphicCanvas.ROUNDRECTANGLE_NO_FILL);
        } else if (c == cmdArc) {
            gc.draw(GraphicCanvas.ARC_NO_FILL);
        } else if (c == cmdFillRect) {
            gc.draw(GraphicCanvas.RECTANGL_FILL);
        } else if (c == cmdFillRoundRect) {
            gc.draw(GraphicCanvas.ROUNDRECTANGLE_FILL);
        } else if (c == cmdFillArc) {
            gc.draw(GraphicCanvas.ARC_FILL);
        } else if (c == cmdFillTriangle) {
            gc.draw(GraphicCanvas.TRIANGLE_FILL);
        }
    }
}