drawimagetest.java

来自「java教程第八章事例」· Java 代码 · 共 124 行

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

public class DrawImageTest extends MIDlet implements CommandListener{

	Display display;
	MyCanvas myCanvas;
	ChoiceGroup setVertical, setHorizontal;
	Form form;
	Command okCmd;

	public DrawImageTest(){
		display = Display.getDisplay(this);
		myCanvas = new MyCanvas();
		form = new Form("选择排版方式");
		okCmd = new Command("确定", Command.OK, 1);
		setVertical = new ChoiceGroup("垂直方向", List.EXCLUSIVE);
		setVertical.append("TOP", null);
		setVertical.append("VCENTER", null);
		setVertical.append("BOTTOM", null);
		setHorizontal = new ChoiceGroup("水平方向", List.EXCLUSIVE);
		setHorizontal.append("LEFT", null);
		setHorizontal.append("HCENTER", null);
		setHorizontal.append("RIGHT", null);
		form.append(setVertical);
		form.append(setHorizontal);
		form.addCommand(okCmd);
		form.setCommandListener(this);
	}


	public void startApp(){
		display.setCurrent(myCanvas);
	}

	public void pauseApp(){

	}


	public void destroyApp(boolean unconditional){

	}

	public void commandAction(Command c, Displayable d){

		if(c == okCmd){
			int index = setVertical.getSelectedIndex();
			switch(index){
				case 0:
					myCanvas.vertical = Graphics.TOP;
				break;
				case 1:
					myCanvas.vertical = Graphics.VCENTER;
				break;
				case 2:
					myCanvas.vertical = Graphics.BOTTOM;
				break;
			}
			index = setHorizontal.getSelectedIndex();
			switch(index){
				case 0:
					myCanvas.horizontal = Graphics.LEFT;
				break;
				case 1:
					myCanvas.horizontal = Graphics.HCENTER;
				break;
				case 2:
					myCanvas.horizontal = Graphics.RIGHT;
				break;
			}
		}
		myCanvas.repaint();
		display.setCurrent(myCanvas);
	}


	class MyCanvas extends Canvas implements CommandListener{

		int vertical;
		int horizontal;
		Command exitCmd;
		Command changeCmd;
		Image image;

		public MyCanvas(){
			try{
				if(display.isColor()){
					image = Image.createImage("/_dukeok8.png");
				}
				else{
					image = Image.createImage("/_dukeok2.png");
				}
			}catch(Exception ex){}
			exitCmd = new Command("退出", Command.EXIT, 1);
			changeCmd = new Command("改变", Command.SCREEN, 1);
			addCommand(exitCmd);
			addCommand(changeCmd);
			setCommandListener(this);
		}

		public void paint(Graphics g){

			g.setColor(0xFFFFFF);
			g.fillRect(0, 0, getWidth(), getHeight());
			g.setColor(0);
			g.drawImage(image, getWidth()/2, getHeight()/2, vertical|horizontal);
			g.setColor(0xFF0000);
			g.drawLine(getWidth()/2, 0, getWidth()/2, getHeight());
			g.drawLine(0, getHeight()/2, getWidth(), getHeight()/2);
		}

		public void commandAction(Command c, Displayable d){

			if(c == exitCmd){
				destroyApp(true);
				notifyDestroyed();
			}
			else if(c == changeCmd){
				display.setCurrent(form);
			}
		}
	}
}