【问题描述】在JavaMe连载(3)-也说MVC设计模式 一文中提到了一个TextEdit类，但没有给出具体实现，TextEdit是采用GameCanvas绘制的文本编辑器。本文结合实例给出实现的方法。

【原理】

1 运用Graphics、GameCanvas绘制文本框和光标。

2 检测到输入事件时，跳转到 高级界面->TextBox 。通过系统调用输入法完成输入。

3 将TextBox输入的值返回给TextEdit对象。

【设计模式】

这个过程有点类似装饰模式，实际上，实现输入的还是TextBox，只是给TextBox装饰了一下，形成了一个漂亮的外观。

【代码清单】

TextEdit.java

1. package com.token.view.components;  
2.  
3. import javax.microedition.lcdui.Font;  
4. import javax.microedition.lcdui.Graphics;  
5. import javax.microedition.lcdui.game.GameCanvas;  
6.  
7. public class TextEdit extends GameCanvas  
8. {  
9.     private Font ft;  
10.       
11.     public int width;  
12.     public int height;  
13.       
14.     public TextEdit(GameCanvas canvas)   
15.     {  
16.         super(false);  
17.           
18.     }  
19.       
20.     //绘制文本框 
21.     public void drawTextBox(GameCanvas canvas, Graphics graphics, String text, int x, int y, boolean cursorBlinkOn)  
22.     {  
23.         //System.out.println("draw"); 
24.         int padding = 4;  
25.         int margin = 2;  
26.           
27.         ft = Font.getFont(Font.FACE_PROPORTIONAL,Font.STYLE_PLAIN,Font.SIZE_MEDIUM);  
28.         graphics.setFont(ft);  
29.           
30.         width = 3*canvas.getWidth()/5+2*padding;  
31.         height = ft.getHeight()+2*padding;  
32.  
33.         graphics.setColor(Color.frame);  
34.         graphics.fillRect(x+1,y+1,width+margin,height+margin);  
35.           
36.         graphics.setColor(Color.frameBg);  
37.         graphics.drawRect(x, y,width, height);  
38.         graphics.setColor(Color.background);  
39.         graphics.fillRect(x+1, y+1,width-1,height-1);  
40.           
41.         graphics.setColor(Color.text);  
42.         graphics.drawString(text, x+padding, y+padding, Graphics.TOP|Graphics.LEFT);  
43.           
44.         drawCursor(graphics, x+ft.stringWidth(text)+padding, y+padding, 1, ft.getHeight(), cursorBlinkOn);  
45.           
46.         canvas.flushGraphics(x,y,width,height);  
47.     }  
48.  
49.  
50.     //绘制光标 
51.     public void drawCursor(Graphics graphics, int x, int y, int width, int height, boolean cursorBlinkOn)  
52.     {  
53.         if(cursorBlinkOn)  
54.         {  
55.             ft = Font.getFont(Font.FACE_PROPORTIONAL,Font.STYLE_PLAIN,Font.SIZE_MEDIUM);  
56.             graphics.setFont(ft);  
57.             graphics.setColor(0x0,0x0,0x0);  
58.             graphics.drawLine(x+width,y,x+width,y+height);  
59.         }  
60.     }  
61. }  

PopUpTextBox.java

1. package com.token.view;  
2.  
3. import javax.microedition.lcdui.Command;  
4. import javax.microedition.lcdui.CommandListener;  
5. import javax.microedition.lcdui.Displayable;  
6. import javax.microedition.lcdui.TextBox;  
7.  
8. import com.token.util.UIController;  
9.  
10. public class PopUpTextBox extends TextBox {  
11.  
12.       private UIController controller;  
13.       protected String canvasText = "";  
14.       private Command okCommand;  
15.       private Command cancelCommand;  
16.       private String object_name = null;  
17.       private String editor = null;  
18.       private Object args_t[];  
19.       private Object[] args;  
20.         
21.       
22.       public PopUpTextBox(UIController control, String title, String text, int maxsize, int constraints)   
23.       {  
24.           super(title, text, maxsize, constraints);  
25.           controller = control;  
26.             
27.           args = new Object[6];  
28.             
29.           okCommand = new Command("确定", Command.OK, 1);  
30.           cancelCommand = new Command("取消", Command.CANCEL, 1);  
31.             
32.           this.addCommand(okCommand);  
33.           this.addCommand(cancelCommand);  
34.           this.setCommandListener(new TextBoxListener());  
35.       }  
36.         
37.       public void init(Object[] args)  
38.       {  
39.           object_name = ((String)args[0]!=null)?(String)args[0]:"";  
40.           editor = ((String)args[1]!=null)?(String)args[1]:"";  
41.           //System.out.println(object_name); 
42.           //System.out.println(editor); 
43.           args_t = args;  
44.           this.setString("");  
45.       }  
46.             
47.       protected void closeTextBox(boolean update) {  
48.             if (update) canvasText = this.getString();  
49.             //System.out.println(canvasText); 
50.  
51.             if(object_name.equals("registScreen"))  
52.             {  
53.                 if(editor.equals("regist_name"))  
54.                 {  
55.                     if(args_t[3]!=""||args_t[3]!=null||args_t[4]!=""||args_t[4]!=null)  
56.                     {  
57.                         args[0] = object_name;  
58.                         args[1] = editor;  
59.                         args[2] = this.canvasText;  
60.                         args[3] = args_t[3];  
61.                         args[4] = args_t[4];  
62.                     }  
63.                     controller.handleEvent(UIController.EventID.EVENT_USER_REGIST_EDIT_BACK,args);  
64.                 }  
65.                 else if(editor.equals("regist_passwd"))  
66.                 {  
67.                     if(args_t[2]!=""||args_t[2]!=null||args_t[4]!=""||args_t[4]!=null)  
68.                     {  
69.                         args[0] = object_name;  
70.                         args[1] = editor;  
71.                         args[2] = args_t[2];  
72.                         args[3] = this.canvasText;  
73.                         args[4] = args_t[4];  
74.                     }  
75.                     controller.handleEvent(UIController.EventID.EVENT_USER_REGIST_EDIT_BACK,args);  
76.                 }  
77.                 else if(editor.equals("regist_passwd_re"))  
78.                 {  
79.                     if(args_t[2]!=""||args_t[2]!=null||args_t[3]!=""||args_t[3]!=null)  
80.                     {  
81.                         args[0] = object_name;  
82.                         args[1] = editor;  
83.                         args[2] = args_t[2];  
84.                         args[3] = args_t[3];  
85.                         args[4] = this.canvasText;  
86.                     }  
87.                     controller.handleEvent(UIController.EventID.EVENT_USER_REGIST_EDIT_BACK,args);  
88.                 }  
89.             }  
90.               
91.            //... 
92.     }  
93.         
94.      private class TextBoxListener implements CommandListener  
95.      {   
96.         public void commandAction(Command command, Displayable disp)  
97.         {  
98.             if(command==okCommand)  
99.             {  
100.                 closeTextBox(true);  
101.             }  
102.             else if(command==cancelCommand)  
103.             {  
104.                 closeTextBox(false);  
105.             }  
106.         }  
107.     }  
108. }  

UserRegist.java

1. package com.token.view;  
2.  
3. import javax.microedition.lcdui.Font;  
4. import javax.microedition.lcdui.Graphics;  
5. import javax.microedition.lcdui.game.GameCanvas;  
6. import com.token.model.*;  
7. import com.token.util.*;  
8. import com.token.view.components.*;  
9.  
10. public class UserRegist extends GameCanvas implements Runnable {  
11.  
12.     private UIController controller;  
13.     private Graphics graphics;  
14.       
15.     private Font ft;  
16.       
17.     private Menu menu;  
18.     private Head head;  
19.     private BackGroud backGroud;  
20.       
21.     private UserDataRecord userRecord;  
22.  
23.     private String title;  
24.       
25.     private TextEdit textEdit_name;  
26.     private TextEdit textEdit_passwd;  
27.     private TextEdit textEdit_passwd_re;  
28.     private int textEdit_name_x;  
29.     private int textEdit_name_y;  
30.     private int textEdit_passwd_x;  
31.     private int textEdit_passwd_y;  
32.     private int textEdit_passwd_re_x;  
33.     private int textEdit_passwd_re_y;  
34.     private int currentlySelectedIndex = 0;  
35.       
36.     private String username;  
37.     private String passwd;  
38.     private String passwd_re;  
39.       
40.     long caretBlinkDelay = 500L;  
41.     long lastCaretBlink = 0;  
42.     private String object_name;  
43.     private String editor;  
44.     private boolean cursorBlinkOn1;  
45.     private boolean cursorBlinkOn2;  
46.     private boolean cursorBlinkOn3;  
47.       
48.     private int width;  
49.     private int height;  
50.       
51.     public UserRegist(UIController control)   
52.     {  
53.         super(false);  
54.         this.controller=control;  
55.         this.title = "用户注册";  
56.         setFullScreenMode(true);  
57.         graphics = getGraphics();  
58.           
59.         width = getWidth();  
60.         height = getHeight();  
61.           
62.         menu = new Menu(this);  
63.         head = new Head(this);  
64.         backGroud = new BackGroud(this);  
65.           
66.         userRecord = new UserDataRecord();  
67.           
68.         textEdit_name = new TextEdit(this);  
69.         textEdit_passwd = new TextEdit(this);  
70.         textEdit_passwd_re = new TextEdit(this);  
71.     }  
72.  
73.     public void show(Object[] args) {  
74.         // TODO Auto-generated method stub 
75.         setFullScreenMode(true);  
76.           
77.         object_name = ((String)args[0]!=null)?(String)args[0]:"";  
78.         editor = ((String)args[1]!=null)?(String)args[1]:"";  
79.         username = ((String)args[2]!=null)?(String)args[2]:"";  
80.         passwd = ((String)args[3]!=null)?(String)args[3]:"";  
81.         passwd_re = ((String)args[4]!=null)?(String)args[4]:"";  
82.           
83.         if(editor.equals("regist_name"))  
84.         {  
85.             cursorBlinkOn1 = true;  
86.             cursorBlinkOn2 = false;  
87.             cursorBlinkOn3 = false;  
88.             currentlySelectedIndex =0;  
89.         }  
90.         else if(editor.equals("regist_passwd"))  
91.         {  
92.             cursorBlinkOn1 = false;  
93.             cursorBlinkOn2 = true;  
94.             cursorBlinkOn3 = false;  
95.             currentlySelectedIndex =1;  
96.         }  
97.         else if(editor.equals("regist_passwd_re"))  
98.         {  
99.             cursorBlinkOn1 = false;  
100.             cursorBlinkOn2 = false;  
101.             cursorBlinkOn3 = true;  
102.             currentlySelectedIndex =2;  
103.         }  
104.           
105.         //System.out.println(object_name); 
106.         //System.out.println(editor); 
107.         draw();  
108.         redraw();  
109.     }  
110.  
111.     public void draw()  
112.     {  
113.         //clearScreen(); 
114.         backGroud.drawBackGroud(this, graphics);  
115.         head.drawHead(this,graphics,this.title);  
116.         menu.drawMenu(this,graphics,"下一步","退出");  
117.         drawBody();  
118.     }  
119.  
120.     private void redraw()  
121.     {  
122.         switch(currentlySelectedIndex)  
123.         {  
124.             case 0:  
125.             {  
126.                 cursorBlinkOn2 = false;  
127.                 cursorBlinkOn3 = false;  
128.                 editor = "regist_name";  
129.                 break;  
130.             }  
131.             case 1:  
132.             {  
133.                 cursorBlinkOn1 = false;  
134.                 cursorBlinkOn3 = false;  
135.                 editor = "regist_passwd";  
136.                 break;  
137.             }  
138.             case 2:  
139.             {  
140.                 cursorBlinkOn1 = false;  
141.                 cursorBlinkOn2 = false;  
142.                 editor = "regist_passwd_re";  
143.                 break;  
144.             }  
145.             default:;  
146.         }  
147.           
148.         textEdit_name.drawTextBox(this, graphics, username, textEdit_name_x, textEdit_name_y, cursorBlinkOn1);  
149.         textEdit_passwd.drawTextBox(this, graphics, passwd, textEdit_passwd_x, textEdit_passwd_y, cursorBlinkOn2);  
150.         textEdit_passwd.drawTextBox(this, graphics, passwd_re, textEdit_passwd_re_x, textEdit_passwd_re_y, cursorBlinkOn3);  
151.         textEdit_name.flushGraphics();  
152.     }  
153.  
154.     public void drawBody()  
155.     {  
156.         int margin =5;  
157.         ft = Font.getFont(Font.FACE_PROPORTIONAL,Font.STYLE_BOLD,Font.SIZE_LARGE);  
158.           
159.         String info = "用户名：\n";  
160.         String info_wrap1[] = StringDealMethod.format(info, width-10, ft);  
161.           
162.         graphics.setFont(ft);  
163.         graphics.setColor(Color.text);  
164.         for(int i=0; i<info_wrap1.length; i++)  
165.         {  
166.             graphics.drawString(info_wrap1[i],5, (i) * ft.getHeight()+40, Graphics.TOP|Graphics.LEFT);  
167.         }  
168.           
169.         textEdit_name_x = 5;  
170.         textEdit_name_y = info_wrap1.length * ft.getHeight()+40;  
171.         textEdit_name.drawTextBox(this, graphics, username, textEdit_name_x, textEdit_name_y, cursorBlinkOn1);  
172.           
173.         info = "用户密码：\n";  
174.         String info_wrap2[] = StringDealMethod.format(info, width-10, ft);  
175.       
176.         graphics.setFont(ft);  
177.         graphics.setColor(Color.text);  
178.         for(int i=0; i<info_wrap2.length; i++)  
179.         {  
180.             graphics.drawString(info_wrap2[i],5, (i+info_wrap1.length) * ft.getHeight()+textEdit_name.height+margin+40, Graphics.TOP|Graphics.LEFT);  
181.         }  
182.           
183.         textEdit_passwd_x = 5;  
184.         textEdit_passwd_y = (info_wrap1.length+info_wrap2.length) * ft.getHeight()+textEdit_name.height+margin+40;  
185.         textEdit_passwd.drawTextBox(this, graphics, passwd, textEdit_passwd_x, textEdit_passwd_y, cursorBlinkOn2);  
186.       
187.         info = "密码确认：\n";  
188.         String info_wrap3[] = StringDealMethod.format(info, width-10, ft);  
189.       
190.         graphics.setFont(ft);  
191.         graphics.setColor(Color.text);  
192.         for(int i=0; i<info_wrap3.length; i++)  
193.         {  
194.             graphics.drawString(info_wrap3[i],5, (i+info_wrap1.length+info_wrap2.length) * ft.getHeight()+textEdit_name.height+textEdit_passwd.height+2*margin+40, Graphics.TOP|Graphics.LEFT);  
195.         }  
196.           
197.         textEdit_passwd_re_x = 5;  
198.         textEdit_passwd_re_y = (info_wrap1.length+info_wrap2.length+info_wrap3.length) * ft.getHeight()+textEdit_name.height+textEdit_passwd.height+2*margin+40;  
199.         textEdit_passwd_re.drawTextBox(this, graphics, passwd_re, textEdit_passwd_re_x, textEdit_passwd_re_y, cursorBlinkOn3);  
200.       
201.           
202.     }  
203.  
204.     public void clearScreen()  
205.     {  
206.         graphics.setColor(0xff,0xff,0xff);  
207.         graphics.fillRect(0, 0, width, height);  
208.     }  
209.  
210.     public void checkTimeStamp()  
211.     {  
212.         long currentTime = System.currentTimeMillis();  
213.         //System.out.println("1"); 
214.         if(lastCaretBlink + caretBlinkDelay < currentTime)  
215.         {  
216.             //System.out.println("2"); 
217.             if(editor.equals("regist_name"))  
218.             {  
219.                 cursorBlinkOn1 =! cursorBlinkOn1;  
220.                 cursorBlinkOn2 = false;  
221.                 cursorBlinkOn3 = false;  
222.             }  
223.             else if(editor.equals("regist_passwd"))  
224.             {  
225.                 cursorBlinkOn1 = false;  
226.                 cursorBlinkOn2 =! cursorBlinkOn2;  
227.                 cursorBlinkOn3 = false;  
228.             }  
229.             else if(editor.equals("regist_passwd_re"))  
230.             {  
231.                 cursorBlinkOn1 = false;  
232.                 cursorBlinkOn2 = false;  
233.                 cursorBlinkOn3 =! cursorBlinkOn3;  
234.             }  
235.             lastCaretBlink = currentTime;  
236.         }  
237.     }  
238.  
239.     public void run()  
240.     {  
241.         //System.out.println("run"); 
242.         while(true)  
243.         {  
244.             checkTimeStamp();  
245.               
246.             redraw();  
247.             try   
248.             {  
249.                 synchronized(this)  
250.                 {  
251.                     //System.out.println("3"); 
252.                     wait(50L);  
253.                 }             
254.             }  
255.             catch(Exception e)  
256.             {  
257.                 e.printStackTrace();  
258.             }  
259.               
260.         }  
261.     }  
262.  
263.     protected void keyPressed(int keyCode)  
264.     {  
265.         switch(keyCode)  
266.         {  
267.             case KeyID.SOFT_RIGHT:  
268.             {  
269.                 controller.handleEvent(UIController.EventID.EVENT_EXIT,null);  
270.                 break;  
271.             }  
272.             case KeyID.SOFT_LEFT:  
273.             {  
274.                 if(username!="" && passwd!=""&&passwd_re!="")  
275.                 {  
276.                     if(passwd.equals(passwd_re))  
277.                     {  
278.                           
279.                           
280.                         userRecord.db_deleteAllRecord();  
281.                         if(userRecord.db_getRecord(1)==null)  
282.                         {  
283.                             UserDataItem userItem = new UserDataItem(1,(username+","+passwd).getBytes());  
284.                             userRecord.db_addRecord(userItem);  
285.                             userItem = null;  
286.                             System.gc();  
287.                         }  
288.                           
289.                         String update = "start";  
290.                         Object [] args = {"activeScreen", null, update};  
291.                         controller.handleEvent(UIController.EventID.EVENT_NEXT_ACTIVE_TOKEN_SCREEN,args);  
292.                     }  
293.                 }  
294.                 break;  
295.             }  
296.             case KeyID.KEY_EDIT:  
297.             case KEY_NUM0:  
298.             case KEY_NUM1:  
299.             case KEY_NUM2:  
300.             case KEY_NUM3:  
301.             case KEY_NUM4:  
302.             case KEY_NUM5:  
303.             case KEY_NUM6:  
304.             case KEY_NUM7:  
305.             case KEY_NUM8:  
306.             case KEY_NUM9:  
307.             {  
308.                 //System.out.println(editor); 
309.                 Object[] args = {object_name,editor,username,passwd,passwd_re};  
310.                 controller.handleEvent(UIController.EventID.EVENT_USER_REGIST_EDIT,args);  
311.                 break;  
312.             }  
313.             default:;  
314.         }  
315.               
316.         keyCode = getGameAction(keyCode);  
317.         switch(keyCode)  
318.         {  
319.             case UP:  
320.             case LEFT:  
321.             {  
322.                 currentlySelectedIndex--;  
323.                 if(currentlySelectedIndex<0)  
324.                 {  
325.                     currentlySelectedIndex=0;  
326.                 }  
327.                 else 
328.                 {  
329.                     redraw();  
330.                 }  
331.                 break;  
332.             }  
333.             case DOWN:  
334.             case RIGHT:  
335.             {  
336.                 currentlySelectedIndex++;  
337.                 if(currentlySelectedIndex>2)  
338.                 {  
339.                     currentlySelectedIndex=2;  
340.                 }  
341.                 else 
342.                 {  
343.                     redraw();  
344.                 }  
345.                   
346.                 break;  
347.             }  
348.         }  
349.     }  
350.  
351. }  
352.  

【分析】

1 文本框的绘制(TextEdit.java)

需要传递GameCanvas、Graphics对象，实现绘图，策略是谁使用，谁传递该参数。此外需要床底文本框左上角坐标(x，y)以及控制光标闪烁的变量cursorBlinkOn。

1. public void drawTextBox(GameCanvas canvas, Graphics graphics, String text, int x, int y, boolean cursorBlinkOn)  
2. {  
3.     //System.out.println("draw"); 
4.     int padding = 4;  
5.     int margin = 2;  
6.       
7.     ft = Font.getFont(Font.FACE_PROPORTIONAL,Font.STYLE_PLAIN,Font.SIZE_MEDIUM);  
8.     graphics.setFont(ft);  
9.       
10.     width = 3*canvas.getWidth()/5+2*padding;  
11.     height = ft.getHeight()+2*padding;  
12.  
13.     graphics.setColor(Color.frame);  
14.     graphics.fillRect(x+1,y+1,width+margin,height+margin);  
15.           
16.     graphics.setColor(Color.frameBg);  
17.     graphics.drawRect(x, y,width, height);  
18.     graphics.setColor(Color.background);  
19.     graphics.fillRect(x+1, y+1,width-1,height-1);  
20.           
21.     graphics.setColor(Color.text);  
22.     graphics.drawString(text, x+padding, y+padding, Graphics.TOP|Graphics.LEFT);  
23.           
24.     drawCursor(graphics, x+ft.stringWidth(text)+padding, y+padding, 1, ft.getHeight(), cursorBlinkOn);  
25.           
26.     canvas.flushGraphics(x,y,width,height);  
27. } 

2 绘制光标(TextEdit.java)

1. public void drawCursor(Graphics graphics, int x, int y, int width, int height, boolean cursorBlinkOn)  
2. {  
3.     if(cursorBlinkOn)  
4.     {  
5.         ft = Font.getFont(Font.FACE_PROPORTIONAL,Font.STYLE_PLAIN,Font.SIZE_MEDIUM);  
6.         graphics.setFont(ft);  
7.         graphics.setColor(0x0,0x0,0x0);  
8.         graphics.drawLine(x+width,y,x+width,y+height);  
9.     }  
10. } 

3 实现光标闪烁

光标闪烁的实现需要用到线程，在UIController.java类中，需要绘制文本框的视图类，需要实现线程接口。

UIController.java

1. case EventID.EVENT_NEXT_USER_REGIST_SCREEN:  
2. case EventID.EVENT_USER_REGIST_EDIT_BACK:  
3. {  
4.             reg.show(args);  
5.             Thread thread = new Thread(reg);  
6.             thread.start();  
7.             midlet.setCurrent(reg);  
8.             break;  
9. } 

UserRegist.java

1. public void checkTimeStamp()  
2. {  
3.     long currentTime = System.currentTimeMillis();  
4.     //System.out.println("1"); 
5.     if(lastCaretBlink + caretBlinkDelay < currentTime)  
6.     {  
7.         //System.out.println("2"); 
8.         if(editor.equals("regist_name"))  
9.         {  
10.             cursorBlinkOn1 =! cursorBlinkOn1;  
11.             cursorBlinkOn2 = false;  
12.             cursorBlinkOn3 = false;  
13.         }  
14.         else if(editor.equals("regist_passwd"))  
15.         {  
16.             cursorBlinkOn1 = false;  
17.             cursorBlinkOn2 =! cursorBlinkOn2;  
18.             cursorBlinkOn3 = false;  
19.         }  
20.         else if(editor.equals("regist_passwd_re"))  
21.         {  
22.             cursorBlinkOn1 = false;  
23.             cursorBlinkOn2 = false;  
24.             cursorBlinkOn3 =! cursorBlinkOn3;  
25.         }  
26.         lastCaretBlink = currentTime;  
27.     }  
28. }  
29.  
30. public void run()  
31. {  
32.     //System.out.println("run"); 
33.     while(true)  
34.     {  
35.         checkTimeStamp();  
36.           
37.         redraw();  
38.         try   
39.         {  
40.             synchronized(this)  
41.             {  
42.                 //System.out.println("3"); 
43.                 wait(50L);  
44.             }             
45.         }  
46.         catch(Exception e)  
47.         {  
48.             e.printStackTrace();  
49.         }  
50.               
51.     }  
52. } 

4 调用高级界面TextBox子类PopUpTextBox

调用时，将调用对象名、编辑对象名、以及编辑框参数传递给PopUpTextBox对象(一定要有，目的是保存编辑框的值，否则多次调用返回时，不同编辑框的值被刷新为空了)

UserRegist.java(KeyPressed)

1. case KeyID.KEY_EDIT:  
2. case KEY_NUM0:  
3. case KEY_NUM1:  
4. case KEY_NUM2:  
5. case KEY_NUM3:  
6. case KEY_NUM4:  
7. case KEY_NUM5:  
8. case KEY_NUM6:  
9. case KEY_NUM7:  
10. case KEY_NUM8:  
11. case KEY_NUM9:  
12. {  
13.     //System.out.println(editor); 
14.     Object[] args = {object_name,editor,username,passwd,passwd_re};  
15.     controller.handleEvent(UIController.EventID.EVENT_USER_REGIST_EDIT,args);  
16.     break;  
17. } 

UIController.java

1. case EventID.EVENT_USER_REGIST_EDIT:  
2. {  
3.      textBox.init(args);  
4.          midlet.setCurrent(textBox);  
5.      break;  
6. } 

5 PopUpTextBox参数的接收

1. public void init(Object[] args)  
2. {  
3.      object_name = ((String)args[0]!=null)?(String)args[0]:"";  
4.      editor = ((String)args[1]!=null)?(String)args[1]:"";  
5.      //System.out.println(object_name); 
6.      //System.out.println(editor); 
7.      args_t = args;  
8.      this.setString("");  
9. } 

6 PopUpTextBox返回输入法输入的值

1. if (update) canvasText = this.getString(); 

7 PopUpTextBox输入值处理

依据调用的对象，以及编辑对象，对输入的值进行处理，传递给父对象编辑框

1. if(object_name.equals("registScreen"))  
2. {  
3.         if(editor.equals("regist_name"))  
4.         {  
5.                 if(args_t[3]!=""||args_t[3]!=null||args_t[4]!=""||args_t[4]!=null)  
6.                 {  
7.                     args[0] = object_name;  
8.                     args[1] = editor;  
9.                     args[2] = this.canvasText;  
10.                     args[3] = args_t[3];  
11.                     args[4] = args_t[4];  
12.                 }  
13.                 controller.handleEvent(UIController.EventID.EVENT_USER_REGIST_EDIT_BACK,args);  
14.     }  
15.     else if(editor.equals("regist_passwd"))  
16.     {  
17.                 if(args_t[2]!=""||args_t[2]!=null||args_t[4]!=""||args_t[4]!=null)  
18.                 {  
19.                     args[0] = object_name;  
20.                     args[1] = editor;  
21.                     args[2] = args_t[2];  
22.                     args[3] = this.canvasText;  
23.                     args[4] = args_t[4];  
24.                 }  
25.                 controller.handleEvent(UIController.EventID.EVENT_USER_REGIST_EDIT_BACK,args);  
26.     }  
27.     else if(editor.equals("regist_passwd_re"))  
28.     {  
29.                 if(args_t[2]!=""||args_t[2]!=null||args_t[3]!=""||args_t[3]!=null)  
30.                 {  
31.                     args[0] = object_name;  
32.                     args[1] = editor;  
33.                     args[2] = args_t[2];  
34.                     args[3] = args_t[3];  
35.                     args[4] = this.canvasText;  
36.                 }  
37.                 controller.handleEvent(UIController.EventID.EVENT_USER_REGIST_EDIT_BACK,args);  
38.     }  
39. } 

8 输入值的显示

(1) 新建对象

1. private TextEdit textEdit_name;  
2. textEdit_name = new TextEdit(this);  

(2) 接受输入的参数

1. object_name = ((String)args[0]!=null)?(String)args[0]:"";  
2. editor = ((String)args[1]!=null)?(String)args[1]:"";  
3. username = ((String)args[2]!=null)?(String)args[2]:"";  
4. passwd = ((String)args[3]!=null)?(String)args[3]:"";  
5. passwd_re = ((String)args[4]!=null)?(String)args[4]:""; 

(3) 光标控制，定位到编辑对象，控制编辑对象的光标闪烁(run方法)

1. private void redraw()  
2. {  
3.     switch(currentlySelectedIndex)  
4.     {  
5.         case 0:  
6.         {  
7.             cursorBlinkOn2 = false;  
8.             cursorBlinkOn3 = false;  
9.             editor = "regist_name";  
10.             break;  
11.         }  
12.         case 1:  
13.         {  
14.             cursorBlinkOn1 = false;  
15.             cursorBlinkOn3 = false;  
16.             editor = "regist_passwd";  
17.             break;  
18.         }  
19.         case 2:  
20.         {  
21.             cursorBlinkOn1 = false;  
22.             cursorBlinkOn2 = false;  
23.             editor = "regist_passwd_re";  
24.             break;  
25.         }  
26.         default:;  
27.     }  
28. //... 
29.  
30. } 

(4) 编辑框的绘制

1. private void redraw()  
2. {  
3.     ...       
4.     textEdit_name.drawTextBox(this, graphics, username, textEdit_name_x, textEdit_name_y, cursorBlinkOn1);  
5.     textEdit_passwd.drawTextBox(this, graphics, passwd, textEdit_passwd_x, textEdit_passwd_y, cursorBlinkOn2);  
6.     textEdit_passwd.drawTextBox(this, graphics, passwd_re, textEdit_passwd_re_x, textEdit_passwd_re_y, cursorBlinkOn3);  
7.     textEdit_name.flushGraphics();  
8. }  

实现的效果如图1所示：

图1 编辑框效果

【参考文献】

(1) http://www.developer.nokia.com/Community/Wiki/Custom_Text_Input_in_Java_ME

(2) j2me跳转到高级界面获得输入法

(3) http://www.iteye.com/topic/394113

(4) http://topic.csdn.net/t/20060906/09/5001597.html

原文链接：http://blog.csdn.net/tandesir/article/details/7544795