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如何在窗體和新日期實例中實現多個圖像

2012-05-17 22 views
1

在CalendarCanvas課程中，想法是在日曆中的任意一天按下，並且將顯示一個表單，其中包含用戶選擇的一天中的實際日期只是今天的日期，因爲它現在正在進行），並且表格下面將是與表格相關的圖像（例如，6月21日（image.jpg））。如何在窗體和新日期實例中實現多個圖像

我有兩個問題。

第一，該程序只喜歡一個圖像是Men.img。它將以三種形式顯示該圖像。其他兩個圖像根本不會顯示。

而我不明白，因爲我第一次開始與一個窗體和images.jpg圖像和該圖像的工作。我所做的只是創建2個新窗體並切換圖像的順序。

我甚至縮小了尺寸（寬度/高度& KB）以匹配Men.jpg，但它仍然不顯示。 ImageItem構造函數中的字符串甚至不顯示。

最後如何創建calendar.getSelectedDate().toString()方法的新實例來顯示新用戶選擇的日期，以便當用戶選擇不同的日期時我可以將其放在圖像的上方？

在keyPressed方法中，已註釋掉的Alert新實例將爲我執行此操作，但我不想要警報，我希望它成爲與用戶選擇哪一天有關的表單的標題。

下面是我的代碼：

類CalendarMidlet：

import java.io.IOException; 
import javax.microedition.midlet.*; 
import javax.microedition.lcdui.*; 

/** 
* @author addylesson 
*/ 
public class CalendarMidlet extends MIDlet { 
    private Display mydisplay; 
    private Command f; 
    private Displayable d; 

    public CalendarMidlet(){} 

    public void startApp() { 
     d = new CalendarCanvas(this); 

     f = new Command("Exit", Command.EXIT, 0); 
     d.addCommand(f); 
     d.setCommandListener(new CommandListener() 
     { 
      public void commandAction(Command c, Displayable s) 
      { 

       if(c == f) 

      notifyDestroyed(); 
      } 
     }); 

     mydisplay = Display.getDisplay(this); 
     mydisplay.setCurrent(d); 

    } 




    public void startOver() { 

     final Displayable d = new CalendarCanvas(this); 

     d.addCommand(f); 

     d.setCommandListener(new CommandListener() 
     { 
      public void commandAction(Command c, Displayable s) 
      { 

       if(c == f) 

      notifyDestroyed(); 
      } 
     }); 
     mydisplay.setCurrent(d); 
    } 

    public void pauseApp() { 
    } 

    public void destroyApp(boolean unconditional) { 
    } 

}

類CalendarCanvas：

import java.io.IOException; 
import java.util.Date; 

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

public class CalendarCanvas extends Canvas 
{ 
    CalendarWidget calendar = null; 
    CalendarMidlet midlet = null; 
     private Alert alert; 
     private List mList; 
     private Command f,e,n; 
     private Display mydisplay; 
     private Form form; 
     private Form form2; 
     private Form form3; 
     private ImageItem imageItem; 
     private ImageItem imageItem2; 
     private ImageItem imageItem3; 



    public CalendarCanvas(final CalendarMidlet m) 
    { 
     String day = calendar.getSelectedDate().toString(); 

       this.midlet = m; 

     calendar = new CalendarWidget(new Date()); 

     calendar.headerFont = Font.getFont(Font.FACE_PROPORTIONAL, Font.STYLE_BOLD, Font.SIZE_LARGE); 
     calendar.weekdayFont = Font.getFont(Font.FACE_PROPORTIONAL, Font.STYLE_BOLD, Font.SIZE_MEDIUM); 
     calendar.weekdayBgColor = 0xccccff; 
     calendar.weekdayColor = 0x0000ff; 
     calendar.headerColor = 0xffffff; 

       form = new Form(day); 
       form2 = new Form("New Page"); 
       form3 = new Form("New Page"); 

       try 
       { 
        imageItem = new ImageItem(
         "Men In Black 3: ", 
         Image.createImage("Men.jpg"), 
         ImageItem.LAYOUT_DEFAULT, 
         "DuKe"); 
        form.append(imageItem); 
       } catch(Exception s) {} 

       try 
       { 
        imageItem2 = new ImageItem(
         "Jordon vs Knicks: ", 
         Image.createImage("images.jpg"), 
         ImageItem.LAYOUT_DEFAULT, 
         "Not"); 
        form2.append(imageItem2); 
       } catch(Exception s) {} 
       try 
       { 
        imageItem3 = new ImageItem(
         "Horoscope: ", 
         Image.createImage("Men.jpg"), 
         ImageItem.LAYOUT_DEFAULT, 
         "DuKe"); 
        form3.append(imageItem3); 
       } catch(Exception s) {} 

       alert = new Alert("Listen", "On this day " 
         +calendar.getSelectedDate().toString()+ "stuff happened", null, null); 
       alert.setTimeout(Alert.FOREVER); 


       n = new Command("Next", Command.SCREEN,0); 
       f = new Command("Back", Command.BACK, 0); 
       e = new Command("Exit", Command.EXIT, 1); 
       form.addCommand(f);    
       form.addCommand(n); 
       form2.addCommand(f); 
       form2.addCommand(n); 
       form3.addCommand(f); 
       form3.addCommand(e); 



       form.setCommandListener(new CommandListener() 
         { 
         public void commandAction(Command c, Displayable s) 
         { 
          if (c == f) 

          m.startOver(); 

          if (c == e) 
           m.notifyDestroyed(); 

          if (c == n) 
           Display.getDisplay(midlet).setCurrent(form2); 
         } 
         }); 
       form2.setCommandListener(new CommandListener() 
         { 
         public void commandAction(Command c, Displayable s) 
         { 
          if (c == f) 

          m.startOver(); 

          if (c == e) 
           m.notifyDestroyed(); 

          if (c == n) 
           Display.getDisplay(midlet).setCurrent(form3); 
         } 
         }); 
       form3.setCommandListener(new CommandListener() 
         { 
         public void commandAction(Command c, Displayable s) 
         { 
          if (c == f) 

          m.startOver(); 

          if (c == e) 
           m.notifyDestroyed(); 
         } 
         }); 


     calendar.initialize(); 
    } 


    protected void keyPressed(int key) 
    { 
     int keyCode = getGameAction(key); 
     String day = calendar.getSelectedDate().toString(); 
     if(keyCode == FIRE) 
     { 
      /*Display.getDisplay(midlet).setCurrent(
       new Alert("Selected date", 
           day, null, 
           AlertType.CONFIRMATION) 
      );*/ 
         Display.getDisplay(midlet).setCurrent(form); 
     } 
     else 
     { 
      calendar.keyPressed(keyCode); 

      repaint(); 
     } 
    } 

    protected void paint(Graphics g) 
    { 
     g.setColor(0xff0000); 
     g.fillRect(0, 0, getWidth(), getHeight()); 

     calendar.paint(g); 
    } 

}

類CalendarWidget：

import java.util.Calendar; 
import java.util.Date; 

import javax.microedition.lcdui.*; 

public class CalendarWidget 
{ 
    static final String[] MONTH_LABELS = new String[]{ 
     "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December" 
    }; 
    static final String[] WEEKDAY_LABELS = new String[]{ 
     "M", "T", "W", "T", "F", "S", "S" 
    }; 
    /* starting week day: 0 for monday, 6 for sunday */ 
    public int startWeekday = 0; 

    /* elements padding */ 
    public int padding = 2; 

    /* cells border properties */ 
    public int borderWidth = 4; 
    public int borderColor = 0x000000; 

    /* weekday labels properties */ 
    public Font weekdayFont = Font.getDefaultFont(); 
    public int weekdayBgColor = 0xcccccc; 
    public int weekdayColor = 0xffffff; 

    /* header (month-year label) properties */ 
    public Font headerFont = Font.getDefaultFont(); 
    public int headerBgColor = 0xff0000; 
    public int headerColor = 0xff0000; 

    /* cells properties */ 
    public Font font = Font.getDefaultFont(); 
    public int foreColor = 0xffffff; 
    public int bgColor = 0xcccccc; 
    public int selectedBgColor = 0x000000; 
    public int selectedForeColor = 0xff0000; 

    /* internal properties */ 
    int width = 0; 
    int height = 0; 
    int headerHeight = 0; 
    int weekHeight = 0; 
    int cellWidth = 0; 
    int cellHeight = 0; 

    /* internal time properties */ 
    long currentTimestamp = 0; 
    Calendar calendar = null; 
    int weeks = 0; 

public CalendarWidget(Date date) 
{ 
    calendar = Calendar.getInstance(); 

    //we'll see these 2 methods later 
    setDate(date); 

    initialize(); 
} 
public Date getSelectedDate() 
{ 
    return calendar.getTime(); 
} 
public void setDate(Date d) 
{ 
    currentTimestamp = d.getTime(); 

    calendar.setTime(d); 

    //weeks number can change, depending on week starting day and month total days 
    this.weeks = (int)Math.ceil(((double)getStartWeekday() + getMonthDays())/7); 
} 
public void setDate(long timestamp) 
{ 
    setDate(new Date(timestamp)); 
} 
void initialize() 
{ 
    //let's initialize calendar size 
    this.cellWidth = font.stringWidth("MM") + 3 * padding; 
    this.cellHeight = font.getHeight() + 15 * padding; 

    this.headerHeight = headerFont.getHeight() + 2 * padding; 
    this.weekHeight = weekdayFont.getHeight() + 2 * padding; 

    this.width = 7 * (cellWidth + borderWidth) + borderWidth; 
    initHeight(); 
} 
void initHeight() 
{ 
    this.height = 
     headerHeight + weekHeight + 
     this.weeks * (cellHeight + borderWidth) + borderWidth; 
} 
int getMonthDays() 
{ 
    int month = calendar.get(Calendar.MONTH); 

    switch(month) 
    { 
    case 3: 
    case 5: 
    case 8: 
    case 10: 
     return 30; 
    case 1: 
     return calendar.get(Calendar.YEAR) % 4 == 0 && calendar.get(Calendar.YEAR) % 100 != 0 ? 29 : 28; 
    default: 
     return 31; 
    } 
} 
int getStartWeekday() 
{ 
    //let's create a new calendar with same month and year, but with day 1 
    Calendar c = Calendar.getInstance(); 

    c.set(Calendar.MONTH, calendar.get(Calendar.MONTH)); 
    c.set(Calendar.YEAR, calendar.get(Calendar.YEAR)); 
    c.set(Calendar.DAY_OF_MONTH, 1); 

    //we must normalize DAY_OF_WEEK returned value 
    return (c.get(Calendar.DAY_OF_WEEK) + 5) % 7; 
} 
public void keyPressed(int key) 
{ 
    switch(key) 
    { 
    case Canvas.UP: 
     go(-7); 
     break; 
    case Canvas.DOWN: 
     go(7); 
     break; 
    case Canvas.RIGHT: 
     go(1); 
     break; 
    case Canvas.LEFT: 
     go(-1); 
     break; 
    } 
} 
void go(int delta) 
{ 
    int prevMonth = calendar.get(Calendar.MONTH); 

    setDate(currentTimestamp + 86400000 * delta); 

    //we have to check if month has changed 
    //if yes, we have to recalculate month height 
    //since weeks number could be changed 
    if(calendar.get(Calendar.MONTH) != prevMonth) 
    { 
     initHeight(); 
    } 
} 
public void paint(Graphics g) 
{ 
    //painting background 
    g.setColor(bgColor); 
    g.fillRect(0, 0, width, height); 

    //painting header (month-year label) 
    g.setFont(headerFont); 
    g.setColor(headerColor); 
    g.drawString(MONTH_LABELS[calendar.get(Calendar.MONTH)] + " " + calendar.get(Calendar.YEAR), width/2, padding, Graphics.TOP | Graphics.HCENTER); 

    //painting week days labels 
    g.translate(0, headerHeight); 

    g.setColor(weekdayBgColor); 
    g.fillRect(0, 0, width, weekHeight); 

    g.setColor(weekdayColor); 
    g.setFont(weekdayFont); 

    for(int i = 0; i < 7; i++) 
    { 
     g.drawString(WEEKDAY_LABELS[(i + startWeekday) % 7], 
      borderWidth + i * (cellWidth + borderWidth) + cellWidth/2, 
      padding, 
      Graphics.TOP | Graphics.HCENTER 
     ); 
    } 


    g.translate(0, weekHeight); 

    g.setColor(borderColor); 

    for(int i = 0; i <= weeks; i++) 
    { 
     g.fillRect(0, i * (cellHeight + borderWidth), width, borderWidth); 
    } 
    for(int i = 0; i <= 7; i++) 
    { 
     g.fillRect(i * (cellWidth + borderWidth), 0, borderWidth, height - headerHeight - weekHeight); 
    } 


    int days = getMonthDays(); 
    int dayIndex = (getStartWeekday() - this.startWeekday + 7) % 7; 

    g.setColor(foreColor); 

    int currentDay = calendar.get(Calendar.DAY_OF_MONTH); 

    for(int i = 0; i < days; i++) 
    { 
     int weekday = (dayIndex + i) % 7; 
     int row = (dayIndex + i)/7; 

     int x = borderWidth + weekday * (cellWidth + borderWidth) + cellWidth/2; 
     int y = borderWidth + row * (cellHeight + borderWidth) + padding; 


     if(i + 1 == currentDay) 
     { 
      g.setColor(selectedBgColor); 
      g.fillRect(
       borderWidth + weekday * (cellWidth + borderWidth), 
       borderWidth + row * (cellHeight + borderWidth), 
       cellWidth, cellHeight); 
      g.setColor(selectedForeColor); 
     } 

     g.drawString("" + (i + 1), x, y, Graphics.TOP | Graphics.HCENTER); 


     if(i + 1 == currentDay) 
     { 
      g.setColor(foreColor); 
     } 
    } 

    g.translate(0, - headerHeight - weekHeight); 
} 
}

來源

2012-05-17 Addy75

回答

1

有中沒有明顯的失誤您發佈的代碼段。

爲了更容易地找出當MIDlet變得如此複雜時可能出現的問題，添加日誌語句並在模擬器中運行它，以觀察控制檯輸出。

您絕對需要在catch塊內添加日誌記錄。爲了找出我爲什麼做出如此強烈的聲明，請在Web上搜索類似的Java吞吞例外。

我建議記錄的其他事項在commandAction以及調用setCurrent時。在開發時，隨時添加更多你認爲需要的地方（keyPressed看起來也是個不錯的選擇）。

public class Log { 
    // utility class to keep logging code in one place 
    public static void log (String message) { 
     System.out.println(message); 
     // when debugging at real device, S.o.p above can be refactored 
     // - based on ideas like one used here (with Form.append): 
     // http://stackoverflow.com/questions/10649974 
     // - Another option would be to write log to RMS 
     // and use dedicated MIDlet to read it from there 
     // - If MIDlet has network connection, an option is 
     // to pass log messages over the network. Etc etc... 
    } 
} 


// ... other classes... 
    // ... 
    catch (Exception e) { 
     Log.log("unexpected exception: [" + e + "]"); 
    } 

    // ... 
    public void commandAction(Command c, Displayable s) { 
     Log.log("command: [" + c.getCommandLabel() 
       + "] at screen: [" + d.getTitle() + "]"); 
     // ... 
    } 

    // ... 
    Log.log("set current: [" + someDisplayable.getTitle() + "]"); 
    mydisplay.setCurrent(someDisplayable); 
    // ... 

    protected void keyPressed(int key) { 
     Log.log("key pressed: [" + getKeyName(key) + "]"); 
     // ... 
    }

來源

2012-05-18 05:59:16 gnat

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