J2ME 用户自定义控件

用户自定义控件

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

package hello;

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

/**
 * @author Administrator
 */
public class CustomItemDemo extends MIDlet implements CommandListener{

    private TextField text;
    //声明用户自定义组件对象
    private SimpleItem  customitem;
    private Command exit;
    
    public void startApp() {
        text=new TextField("姓名","",30,TextField.ANY);
        Form form=new Form("SimpleItemMIDlet");
        //构造用户自定义组件实例
        customitem =new SimpleItem("自定义控件");
        //将用户自定义组件添加到Form表单中
        form.append(customitem);
        form.append(text);
        exit=new Command("退出",Command.EXIT,0);
        form.addCommand(exit);
        form.setCommandListener(this);
        Display.getDisplay(this).setCurrent(form);
    }

    public void pauseApp() {
    }

    public void destroyApp(boolean unconditional) {
    }

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



//定义用户自定义控件类
class SimpleItem extends CustomItem {

    public SimpleItem(String title)
    {
        super(title);
    }

    protected int getMinContentWidth() {
       return 100;
    }

    protected int getMinContentHeight() {
       return 60;
    }

    protected int getPrefContentWidth(int height) {
       return getMinContentWidth();
    }

    protected int getPrefContentHeight(int width) {
        return getMinContentHeight();
    }

    protected void paint(Graphics g, int w, int h) {
        g.drawRect(0, 0, w-1, h-1);
        g.setColor(0x000000ff);
        g.drawString("用户自定义控件", 0, 0, 0);
    }

    public void commandAction(Command c,Item i)
    {
        repaint();
    }

}