3. 举例
下面是用KJava编写的一个可以在A6288型手机上运行的简单的例子。具体程序如下：
import Java.io.*;
import Javax.microedition.lcdui.*;
import Javax.microedition.midlet.*;
public class HelloWorld extends MIDlet implements CommandListener
{
private MainCanvas myCanvas;
private Display myDisplay;
private Command c1,c2,c3;
HelloWorld()
{
myCanvas=new MainCanvas();
myCanvas.addCommand(c1=new Command("First",Command.SCREEN,1));
myCanvas.addCommand(c2=new Command("Second",Command.SCREEN,1));
myCanvas.addCommand(c3=new Command("Third",Command.SCREEN,1));
myCanvas.setCommandListener(this);
myDisplay = Display.getDisplay(this);
myDisplay = Display.getDisplay(this);
}
public void startApp() throws MIDletStateChangeException
{
myCanvas.setUp("first");
myDisplay.setCurrent(myCanvas);
}
public void pauseApp() { }
public void destroyApp(boolean unconditional) { }
public void commandAction(Command c,Displayable d)
{ myCanvas.setUp(c.getLabel()); }
class MainCanvas extends Canvas
{
String ts;
MainCanvas()
{
super();
ts=new String("first");
}
public void setUp(String s)
{ ts=new String(s); }
public void paint(Graphics g)
{
g.setColor(0xFFFFFF);
g.fillRect(0, 0, getWidth(), getHeight());
g.setColor(0);
g.drawString("Current is the "+ts,getWidth()/2,60,Graphics.HCENTER | Graphics.TOP);
}
}
} |
程序运行后，可以根据用户选择的不同菜单项显示不同的内容。
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