我的J2ME编程练习（8）——Canvas3

2008-02-23 09:53:28来源：互联网阅读 ()

/*
* Canvas3let.Java
*
* Created on 2005年4月20日, 下午3:55
*/

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

/**
*
* @author Administrator
* @version
*/
public class Canvas3let extends MIDlet implements CommandListener{
private Display aDisplay;

private Command okCommand;
private Command exitCommand;
private Command backCommand;

private TextBox aTextBox;

private Alert showAlert;

private Image showImage;

private MyCanvas aMyCanvas;

public Canvas3let(){
exitCommand=new Command("退出",Command.EXIT,1);
okCommand=new Command("进入",Command.OK,1);
try{
showImage=Image.createImage("/sohu.png");
}
catch(Exception e){}

showAlert=new Alert("Loading...","载入中……",showImage,AlertType.INFO);

aTextBox=new TextBox("KeyPress Test",
"按下进入键后，即可进入显示界面，可以显示所按按键",
25,TextField.ANY);

aTextBox.addCommand(exitCommand);
aTextBox.addCommand(okCommand);
aTextBox.setCommandListener(this);

}
public void startApp() {
aDisplay=Display.getDisplay(this);
aDisplay.setCurrent(aTextBox);
}

public void pauseApp() {
}

public void destroyApp(boolean unconditional) {
}

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

aMyCanvas=new MyCanvas();
aDisplay.setCurrent(aMyCanvas);
}

}

public class MyCanvas extends Canvas implements CommandListener{

String keyName="";
public MyCanvas(){
backCommand=new Command("后退",Command.EXIT,1);
addCommand(backCommand);
setCommandListener(this);
}

public void paint(Graphics g){
//清除屏幕
g.setColor(0xFFFFFF);
g.fillRect(0,0,getWidth(),getHeight());

//设置字体颜色并画出所按键的名称
g.setColor(0);
g.drawString(keyName,100,100,Graphics.LEFT|Graphics.BOTTOM);
}

public void commandAction(Command c , Displayable d){
if (c==backCommand){
hideNotify();
//aDisplay.setCurrent(aTextBox);
}

}

public void keyPressed(int keyCode){
keyName=getKeyName(keyCode);
repaint();
}

protected void hideNotify(){
aDisplay.setCurrent(showAlert,aTextBox);
}
}
}