textboxconstraintsdemo.java

《J2ME图形应用基础》中的例子

/*
 * TextBoxConstraintsDemo.java
 *
 * Created on 2005年3月5日, 下午10:38
 */

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

/**
 *
 * @author  Liu Bin
 * @version 1.0
 */
public class TextBoxConstraintsDemo extends MIDlet
        implements CommandListener {
    
    //Display管理
    Display display = null;
    
    //TextBox对象
    TextBox tb = new TextBox("输入限制演示",   //设置标题
            "任何文本abc,23@",                  //设置内容
            50,                                 //设置最大字符数
            TextField. ANY);                    //可以接受任何输入
    
    //创建命令按钮
    static final Command cmdEmail =
            new Command("E-mail地址", Command.ITEM,1);
    static final Command cmdPhoneNumber =
            new Command("电话号码", Command.ITEM,1);
    static final Command cmdURL =
            new Command("URL", Command.ITEM,1);
    static final Command cmdDecimal =
            new Command("小数", Command.ITEM,1);
    
    
    static final Command cmdSize =
            new Command("文本大小", Command.ITEM,2);
    static final Command cmdUneditable =
            new Command("UNEDITABLE", Command.ITEM,2);
    static final Command cmdPassword =
            new Command("PASSWORD", Command.ITEM,2);
    static final Command cmdINITIAL_CAPS_WORD =
            new Command("INITIAL_CAPS_WORD", Command.ITEM,2);
    static final Command cmdINITIAL_CAPS_SENTENCE =
            new Command("INITIAL_CAPS_SENTENCE", Command.ITEM,2);
    static final Command cmdCONSTRAINT_MASK =
            new Command("CONSTRAINT_MASK", Command.ITEM,2);
    static final Command cmdExit = new Command("退出", Command.STOP, 2);
    
    public void startApp() {
        //设置Displayable对象
        tb.addCommand(cmdExit);
        tb.addCommand(cmdEmail);
        tb.addCommand(cmdPhoneNumber);
        tb.addCommand(cmdURL);
        tb.addCommand(cmdDecimal);
        
        tb.addCommand(cmdSize);
        tb.addCommand(cmdUneditable);
        tb.addCommand(cmdPassword);
        tb.addCommand(cmdINITIAL_CAPS_WORD);
        tb.addCommand(cmdINITIAL_CAPS_SENTENCE);
        tb.addCommand(cmdCONSTRAINT_MASK);
        
        tb.setCommandListener(this);
        
        
        
        display = Display.getDisplay(this); //获得当前MIDlet的Display对象
        display.setCurrent(tb);           //设置tb对象为当前显示对象
    }
    
    public void pauseApp() {
    }
    
    public void destroyApp(boolean unconditional) {
        notifyDestroyed();
    }
    
    
    /**
     * 处理命令按钮事件
     */
    public void commandAction(Command c, Displayable d) {
        String label = c.getLabel();
        if (label.equals("退出")) {
            destroyApp(true);
        } else if(label.equals("E-mail地址")) {
            tb.setConstraints(TextField.EMAILADDR);
        } else if(label.equals("电话号码")) {
            tb.setConstraints(TextField.PHONENUMBER);
        } else if(label.equals("小数")) {
            tb.setConstraints(TextField.DECIMAL);
        } else if(label.equals("URL")) {
            tb.setConstraints(TextField.URL);
        } else if(label.equals("文本大小")) {
            //获得文本框的输入内容
            String str = tb.getString();
            System.out.println("当前文本内容为：" + str);
            System.out.println("通过size函数获得的大小：" + tb.size());
            System.out.println("通过String.length()函数获得的大小：" +
                    str.length());
            
        } else if(label.equals("UNEDITABLE")) {
            int con = tb.getConstraints();
            con |= TextField.UNEDITABLE;
            tb.setConstraints(con);
            System.out.println("执行UNEDITABLE功能后的输入限制为：" + con);
        } else if(label.equals("PASSWORD")) {
            int con = tb.getConstraints();
            System.out.println("执行PASSWORD功能前的输入限制为：" + con);
            con |= TextField.PASSWORD;
            tb.setConstraints(con);
            System.out.println("执行PASSWORD功能后的输入限制为：" + con);
        } else if(label.equals("INITIAL_CAPS_WORD")) {
            int con = tb.getConstraints();
            con |= TextField.INITIAL_CAPS_WORD;
            tb.setConstraints(con);
            System.out.println("执行INITIAL_CAPS_WORD功能后的输入限制为："+con);
        } else if(label.equals("INITIAL_CAPS_SENTENCE")) {
            int con = tb.getConstraints();
            con |= TextField.INITIAL_CAPS_SENTENCE;
            tb.setConstraints(con);
            System.out.println("执行INITIAL_CAPS_SENTENCE功能后的输入限制为：" 
                    + con);
        } else if(label.equals("CONSTRAINT_MASK")) {
            int con = tb.getConstraints();
            System.out.println("当前的输入约束为：" + con);
            con &= TextField.CONSTRAINT_MASK;
            tb.setConstraints(con);
            System.out.println("执行CONSTRAINT_MASK功能后的输入约束：" + con);
        }
    }
}