javaME 学习之-简单通讯录

界面说明:  欢迎界面--包含 退出按钮   电话本按钮  欢迎说明
                 主界面--显示通讯录列表    包含 返回(回到欢迎界面) 按钮    删除按钮(对列表中的记录删除)  添加按钮(跳转到添加界面)  
               添加界面--有姓名、号码文本框   保存和返回按钮

代码说明：

  1.欢迎界面 WelcomeCanvas.class
        

 1package org;
 2
 3import javax.microedition.lcdui.Canvas;
 4import javax.microedition.lcdui.Command;
 5import javax.microedition.lcdui.CommandListener;
 6import javax.microedition.lcdui.Displayable;
 7import javax.microedition.lcdui.Font;
 8import javax.microedition.lcdui.Graphics;
 9
10public class WelcomeCanvas extends Canvas implements CommandListener {
11
12    private Command cmdExit = new Command("退出", Command.EXIT, 1);
13    private Command cmdPhone = new Command("电话本", Command.SCREEN, 1);
14    private MainMIDlet mid;
15
16    protected void paint(Graphics g) {
17
18        g.setColor(255, 0, 0);
19        g.setFont(Font.getFont(Font.FACE_SYSTEM, Font.STYLE_BOLD,
20                Font.SIZE_LARGE));
21        String welcomeString = "欢迎使用";
22        int fontStringWidth = g.getFont().stringWidth(welcomeString);// 字长
23        int fontStringHeight = g.getFont().getHeight();// 高度
24        // 显示屏幕正中央
25        g.drawString(welcomeString, this.getWidth() / 2 - fontStringWidth / 2,
26                this.getHeight() / 2 - fontStringHeight / 2, Graphics.LEFT
27                        | Graphics.TOP);
28    }
29
30    public WelcomeCanvas(MainMIDlet midDlet) {
31        this.addCommand(cmdExit);
32        this.addCommand(cmdPhone);
33        this.setCommandListener(this);
34        this.mid = midDlet;
35    }
36
37    public void commandAction(Command c, Displayable d) {
38
39        if (c == cmdExit) {
40            mid.notifyDestroyed();
41        }
42        if (c == cmdPhone) {
43            mid.changeCurrentUI("phoneList");
44        }
45    }
46
47}
48

2.通讯列表   PhoneList.class

 1package org;
 2
 3import javax.microedition.lcdui.Command;
 4import javax.microedition.lcdui.CommandListener;
 5import javax.microedition.lcdui.Displayable;
 6import javax.microedition.lcdui.List;
 7import javax.microedition.rms.RecordStoreException;
 8
 9public class PhoneList extends List implements CommandListener {
10
11    private Command cmdBack = new Command("返回", Command.BACK, 1);
12    private Command cmdAdd = new Command("添加", Command.SCREEN, 1);
13    private Command cmdDelete = new Command("删除", Command.SCREEN, 2);
14    private MainMIDlet mid;
15
16    public PhoneList(MainMIDlet mid) {
17        super("电话本", List.IMPLICIT);
18        this.addCommand(cmdBack);
19        this.addCommand(cmdAdd);
20        this.addCommand(cmdDelete);
21        this.setCommandListener(this);
22        this.mid = mid;
23    }
24
25    public void commandAction(Command c, Displayable d) {
26         
27        //返回
28        if (c == cmdBack) {
29            mid.changeCurrentUI("welcome");
30        }
31        //添加
32        if (c == cmdAdd) {
33            mid.changeCurrentUI("PhoneAddForm");
34        }
35        //删除
36        if (c == cmdDelete) {
37            try {
38                mid.rStoreOperate.deleteRecord(this.getString(this
39                        .getSelectedIndex()));
40                
41                mid.LoadData();
42            } catch (RecordStoreException e) {
43                // TODO Auto-generated catch block
44                e.printStackTrace();
45            }
46        }
47
48    }
49}
50

3.添加界面  PhoneNumberAddForm.class

 1package org;
 2
 3import javax.microedition.lcdui.Command;
 4import javax.microedition.lcdui.CommandListener;
 5import javax.microedition.lcdui.Displayable;
 6import javax.microedition.lcdui.Form;
 7import javax.microedition.lcdui.StringItem;
 8import javax.microedition.lcdui.TextField;
 9import javax.microedition.rms.RecordStoreException;
10
11public class PhoneNumberAddForm extends Form implements CommandListener {
12
13    private Command cmdAddNumber = new Command("添加号码", Command.OK, 2);
14
15    private Command cmdBack = new Command("返回", Command.BACK, 3);
16
17    private TextField txtName = new TextField("姓名", "", 50, TextField.ANY);
18
19    private TextField txtNumber = new TextField("号码", "", 50, TextField.NUMERIC);
20
21    private StringItem alertInfo = new StringItem("", "");
22
23    MainMIDlet midDlet;
24
25    public PhoneNumberAddForm(MainMIDlet mid) {
26        super("添加电话号码");
27        this.addCommand(cmdAddNumber);
28        this.addCommand(cmdBack);
29        this.append(txtName);
30        this.append(txtNumber);
31        this.append(alertInfo);
32        this.setCommandListener(this);
33        this.midDlet = mid;
34
35    }
36
37    public void commandAction(Command c, Displayable d) {
38
39        if (c == cmdBack) {
40            midDlet.changeCurrentUI("phoneList");
41        }
42        if (c == cmdAddNumber) {
43            try {
44
45                midDlet.rStoreOperate.addRecord(txtName.getString() + "-"
46                        + txtNumber.getString());
47
48                alertInfo.setText("添加成功！");
49                txtName.setString("");
50                txtNumber.setString("");
51
52            } catch (RecordStoreException e) {
53                e.printStackTrace();
54                alertInfo.setText("添加失败！");
55            }
56        }
57    }
58}
59

4.主界面MIDlet

 1package org;
 2
 3import java.util.Enumeration;
 4import java.util.Vector;
 5
 6import javax.microedition.lcdui.Display;
 7import javax.microedition.midlet.MIDlet;
 8import javax.microedition.midlet.MIDletStateChangeException;
 9import javax.microedition.rms.RecordStoreException;
10
11public class MainMIDlet extends MIDlet {
12
13    private Display display;
14    WelcomeCanvas wc = new WelcomeCanvas(this);
15    PhoneList pList = new PhoneList(this);
16    PhoneNumberAddForm phoneNumberAddForm = new PhoneNumberAddForm(this);
17    public RecordStoreOperate rStoreOperate = new RecordStoreOperate("number");
18
19    public MainMIDlet() {
20        display = Display.getDisplay(this);
21    }
22
23    protected void destroyApp(boolean unconditional)
24            throws MIDletStateChangeException {
25
26    }
27
28    protected void pauseApp() {
29
30    }
31
32    // /加载通讯列表
33    public void LoadData() {
34        try {
35            pList.deleteAll();
36            Vector vector = rStoreOperate.loadData();
37            Enumeration en = vector.elements();
38            while (en.hasMoreElements()) {
39                pList.append(en.nextElement().toString(), null);
40            }
41        } catch (RecordStoreException e) {
42            e.printStackTrace();
43        }
44
45    }
46
47    protected void startApp() throws MIDletStateChangeException {
48        changeCurrentUI("welcome");
49    }
50
51    public void changeCurrentUI(String name) {
52        if (name.equals("phoneList")) {
53            display.setCurrent(pList);
54            LoadData();
55        }
56        if (name.equals("welcome")) {
57            display.setCurrent(wc);
58        }
59        if (name == "PhoneAddForm") {
60            display.setCurrent(phoneNumberAddForm);
61
62        }
63    }
64
65}
66

5.RMS操作

 1package org;
 2
 3import java.util.Vector;
 4
 5import javax.microedition.rms.RecordEnumeration;
 6import javax.microedition.rms.RecordFilter;
 7import javax.microedition.rms.RecordStore;
 8import javax.microedition.rms.RecordStoreException;
 9import javax.microedition.rms.RecordStoreNotOpenException;
10
11public class RecordStoreOperate implements RecordFilter {
12
13    private RecordStore rStore = null;
14
15    public RecordStoreOperate(String rsName) {
16
17        try {
18            rStore = RecordStore.openRecordStore(rsName, true);
19        } catch (RecordStoreException e) {
20            e.printStackTrace();
21        }
22    }
23
24    public Vector loadData() throws RecordStoreNotOpenException,
25            RecordStoreException {
26
27        Vector v = new Vector();
28
29        RecordEnumeration re = rStore.enumerateRecords(this, null, false);
30        while (re.hasNextElement()) {
31            String str = new String(re.nextRecord());
32            v.addElement(str);
33        }
34        return v;
35    }
36
37    // /删除记录 by ID
38    public void deleteRecord(int id) throws RecordStoreException {
39        rStore.deleteRecord(id);
40    }
41
42    /** *//**
43     * 删除记录 注意点 删除记录后 该记录的recordId 还是保存着的 所以删除不能把记录的numRecord当做RecordId来用
44     * 我这里采取置为空字符窜" " 而且长度要大于0 如果为"" 读取的时候就会当做NULL 而且此处也并非真正意思上的删除
45     * 删除记录也不是真正意义上的删除  只是把值改成" "  读取过滤
46     * **/
47
48    public void deleteRecord(String record) throws RecordStoreException {
49
50        int numRecords = rStore.getNumRecords();
51
52        for (int i = 0; i < numRecords; i++) {
53            byte[] b = rStore.getRecord(i + 1);
54
55            if (new String(b).equals(record)) {
56
57                rStore.setRecord(i + 1, " ".getBytes(), 0, 1);
58            }
59        }
60
61    }
62
63    // 添加记录
64    public void addRecord(String rsString) throws RecordStoreException {
65        byte[] b = rsString.getBytes();
66        rStore.addRecord(b, 0, b.length);
67    }
68     
69    
70    /** *//**过滤 " "  意为" "是已被删除
71    **返回true 记录集中包含该条件的记录 flase返回不符此条件的记录
72    **/
73     public boolean matches(byte[] value) {
74
75        return !new String(value).equals(" ");
76    }
77}
78