setcurrenttest.java

来自「J2ME手机游戏开发技术详解随书光盘」· Java 代码 · 共 38 行

import javax.microedition.midlet.MIDlet;
import javax.microedition.lcdui.*;
public class setCurrentTest extends MIDlet implements CommandListener {
    private Display display;
    private TextBox textBox;
    private Command cmd = new Command("null",Command.SCREEN,1);
    public setCurrentTest() {
    display = Display.getDisplay(this);
    textBox = new TextBox("Display演示","当前所显示的屏幕对象",50,0);
    textBox.addCommand(cmd);
    textBox.setCommandListener(this);
    }
    protected void startApp() {
    display.setCurrent(textBox);

   	

    }
    protected void destroyApp(boolean unconditional) {
    }
    protected void pauseApp() {
    }
    public void commandAction(Command c, Displayable s) {
    System.out.println("调用display.setCurrent(textBox);");	
    System.out.println("\t当前显示屏幕对象为:"+display.getCurrent().toString());
    System.out.println("\t当前对象是否可见:"+display.getCurrent().isShown());
    display.setCurrent(null);
    System.out.println("调用display.setCurrent(null);");	
    System.out.println("\t当前显示屏幕对象为:"+display.getCurrent().toString());
    System.out.println("\t当前对象是否可见:"+display.getCurrent().isShown());
    display.setCurrent(display.getCurrent());
    System.out.println("调用display.setCurrent(display.getCurrent());");	
    System.out.println("\t当前显示屏幕对象为:"+display.getCurrent().toString());
    System.out.println("\t当前对象是否可见:"+display.getCurrent().isShown());
	}	
    
}