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我一直在這裏關注本教程：Link to tutorial。我似乎無法讓應用程序正常顯示。當我運行應用程序，我希望看到像教程CalendarCanvas屏幕，但我得到這個：Java ME日曆不顯示
這裏是我的代碼，我使用的是標準MIDP類。
類CreateCalendar：
import java.util.Date;
import java.util.Calendar;
import javax.microedition.lcdui.*;
import javax.microedition.midlet.MIDlet;
public class CreateCalendar
{
/**
* Array of strings which holds data for the month and day
* for the calendar application.
*/
static final String[] month_labels = new String[]
{
"January", "Febuary", "March", "April", "May", "June", "July", "August", "Sepetember", "October", "November", "Decemeber"
};
static final String[] weekdays_labels = new String[]
{
"Mon", "Tue", "Wed", "Thur", "Fri", "Sat", "Sun"
};
public int startWeekday = 0;
public int padding = 1;
public int borderWidth = 4;
public int borderColor = 0x009900;
/**
* Weekday Labels
*/
public Font weekdayFont = Font.getDefaultFont();
public int weekdayBackgroundColor = 0x009900;
public int weekdayColor = 0xffffff;
/**
* Month/Year Labels
*/
public Font headerFont = Font.getDefaultFont();
public int headerBackgroundColor = 0x009900;
public int headerColor = 0xffffff;
/**
* Cells Labels
*/
public Font font = Font.getDefaultFont();
public int foreColor = 0xffffff;
public int backgroundColor = 0x009900;
public int selectedBackgroundColor = 0xCCFF00;
public int selectedForegroundColor = 0xffffff;
/**
* Size 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 CreateCalendar(Date date)
{
calendar = Calendar.getInstance();
setDate(date);
initialize();
}
public Date getSelectedDate()
{
return calendar.getTime();
}
public void setDate(Date d)
{
currentTimeStamp = d.getTime();
calendar.setTime(d);
this.weeks = (int)Math.ceil(((double)getStartWeekday() + getMonthDays())/7);
}
public void setDate(long timestamp)
{
setDate(new Date(timestamp));
}
public void initialize()
{
this.cellWidth = font.stringWidth("MM") + 2 * padding;
this.cellHeight = font.getHeight() + 2 * 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:
int year = calendar.get(Calendar.YEAR);
return (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0) ? 29 : 28;
default:
return 31;
}
}
int getStartWeekday()
{
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);
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 + 864000000 * delta);
if(calendar.get(Calendar.MONTH) != prevMonth)
{
initHeight();
}
}
public void paint(Graphics g)
{
g.setColor(backgroundColor);
g.fillRect(0, 0, width, height);
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);
g.translate(0, headerHeight);
g.setColor(weekdayBackgroundColor);
g.fillRect(0, 0, width, weekHeight);
g.setColor(weekdayColor);
g.setFont(weekdayFont);
for(int i = 0; i < 7; i++)
{
g.drawString(weekdays_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 + cellWidth) + padding;
if(i + 1 == currentDay)
{
g.setColor(selectedBackgroundColor);
g.fillRect(borderWidth + weekday * (cellWidth + borderWidth), borderWidth + row * (cellHeight + borderWidth), cellWidth, cellHeight);
g.setColor(selectedForegroundColor);
}
g.drawString("" + (i + 1), x, y, Graphics.TOP | Graphics.HCENTER);
if(i + 1 == currentDay)
{
g.setColor(foreColor);
}
}
g.translate(0, - headerHeight - weekHeight);
}
private Date getTime() {
throw new UnsupportedOperationException("Not yet implemented"); //TODO get current Time
}
類CalFrontEnd（擴展的MIDlet）：在類CreateCalendar
public class CalFrontEnd extends MIDlet
{
public CreateCalendar calendar;
protected Display display;
protected Form mainForm;
public CalFrontEnd()
{
}
public void startApp()
{
calendar = new CreateCalendar(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.weekdayBackgroundColor = 0xccccff;
calendar.weekdayColor = 0x0000ff;
calendar.headerColor = 0xffffff;
calendar.initialize();
display.getDisplay(this).setCurrent(
new intCalendar(this));
}
public void pauseApp()
{
}
public void destroyApp(boolean destroy)
{
notifyDestroyed();
}
}}
最可能出錯的第一件事是方法名稱'KeyPressed'。 Java是區分大小寫的，並且您參考的教程，它有'keyPressed'，以小寫'k'開始，這對於匹配Canvas API非常重要。另外，用你的[代碼片段]（http://www.sscce.org/「最好是Short，Self Contained，Correct（Compilable），Example」），不能說出'new intCalendar（this） ' - 這使得無法確定發生了什麼問題 – gnat 2012-04-28 18:51:50