我遵循本教程的教程1和2，以便使用自定义HorizontalListView类获得水平列表视图视图。下面是我的代码。一切正常，但问题是当应用程序启动时，它显示的日期是从 1 开始，而不是从当前日期开始。
我能做些什么？
这是我的快照
public class MyCalendarActivity extends Activity implements
OnClickListener {
private static final String tag = "MyCalendarActivity";
private TextView currentMonth;
private Button selectedDayMonthYearButton;
private ImageView prevMonth;
private ImageView nextMonth;
private HorizontalListView calendarView;
private GridCellAdapter adapter;
private Calendar _calendar;
@SuppressLint("NewApi")
private int month, year;
@SuppressWarnings("unused")
@SuppressLint({ "NewApi", "NewApi", "NewApi", "NewApi" })
private final DateFormat dateFormatter = new DateFormat();
private static final String dateTemplate = "MMMM yyyy";
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.my_calendar_view);
_calendar = Calendar.getInstance(Locale.getDefault());
month = _calendar.get(Calendar.MONTH) + 1;
year = _calendar.get(Calendar.YEAR);
Log.d(tag, "Calendar Instance:= " + "Month: " + month + " " + "Year: "
+ year);
selectedDayMonthYearButton = (Button) this
.findViewById(R.id.selectedDayMonthYear);
selectedDayMonthYearButton.setText("Selected: ");
prevMonth = (ImageView) this.findViewById(R.id.prevMonth);
prevMonth.setOnClickListener(this);
currentMonth = (TextView) this.findViewById(R.id.currentMonth);
currentMonth.setText(DateFormat.format(dateTemplate,
_calendar.getTime()));
nextMonth = (ImageView) this.findViewById(R.id.nextMonth);
nextMonth.setOnClickListener(this);
// HorizontalListView listview = (HorizontalListView)
findViewById(R.id.listview);
calendarView = (HorizontalListView) this.findViewById(R.id.calendar);
// Initialised
adapter = new GridCellAdapter(getApplicationContext(),
R.id.calendar_day_gridcell, month, year);
adapter.notifyDataSetChanged();
calendarView.setAdapter(adapter);
}
/**
*
* @param month
* @param year
*/
private void setGridCellAdapterToDate(int month, int year) {
adapter = new GridCellAdapter(getApplicationContext(),
R.id.calendar_day_gridcell, month, year);
_calendar.set(year, month - 1, _calendar.get(Calendar.DAY_OF_MONTH));
currentMonth.setText(DateFormat.format(dateTemplate,
_calendar.getTime()));
adapter.notifyDataSetChanged();
calendarView.setAdapter(adapter);
}
@Override
public void onClick(View v) {
if (v == prevMonth) {
if (month <= 1) {
month = 12;
year--;
} else {
month--;
}
Log.d(tag, "Setting Prev Month in GridCellAdapter: " + "Month: "
+ month + " Year: " + year);
setGridCellAdapterToDate(month, year);
}
if (v == nextMonth) {
if (month > 11) {
month = 1;
year++;
} else {
month++;
}
Log.d(tag, "Setting Next Month in GridCellAdapter: " + "Month: "
+ month + " Year: " + year);
setGridCellAdapterToDate(month, year);
}
}
@Override
public void onDestroy() {
Log.d(tag, "Destroying View ...");
super.onDestroy();
}
// Inner Class
public class GridCellAdapter extends BaseAdapter implements OnClickListener {
private static final String tag = "GridCellAdapter";
private final Context _context;
private final List<String> list;
private static final int DAY_OFFSET = 1;
private final String[] weekdays = new String[] { "Sun", "Mon", "Tue",
"Wed", "Thu", "Fri", "Sat" };
private final String[] months = { "January", "February", "March",
"April", "May", "June", "July", "August", "September",
"October", "November", "December" };
private final int[] daysOfMonth = { 31, 28, 31, 30, 31, 30, 31, 31, 30,
31, 30, 31 };
private int daysInMonth;
private int currentDayOfMonth;
private int currentWeekDay;
private Button gridcell;
private TextView num_events_per_day;
private final HashMap<String, Integer> eventsPerMonthMap;
private final SimpleDateFormat dateFormatter = new SimpleDateFormat(
"dd-MMM-yyyy");
// Days in Current Month
public GridCellAdapter(Context context, int textViewResourceId,
int month, int year) {
super();
this._context = context;
this.list = new ArrayList<String>();
Log.d(tag, "==> Passed in Date FOR Month: " + month + " "
+ "Year: " + year);
Calendar calendar = Calendar.getInstance();
setCurrentDayOfMonth(calendar.get(Calendar.DAY_OF_MONTH));
setCurrentWeekDay(calendar.get(Calendar.DAY_OF_WEEK));
Log.d(tag, "New Calendar:= " + calendar.getTime().toString());
Log.d(tag, "CurrentDayOfWeek :" + getCurrentWeekDay());
Log.d(tag, "CurrentDayOfMonth :" + getCurrentDayOfMonth());
// Print Month
printMonth(month, year);
// Find Number of Events
eventsPerMonthMap = findNumberOfEventsPerMonth(year, month);
}
private String getMonthAsString(int i) {
return months[i];
}
private String getWeekDayAsString(int i) {
return weekdays[i];
}
private int getNumberOfDaysOfMonth(int i) {
return daysOfMonth[i];
}
public String getItem(int position) {
return list.get(position);
}
@Override
public int getCount() {
return list.size();
}
/**
* Prints Month
*
* @param mm
* @param yy
*/
private void printMonth(int mm, int yy) {
Log.d(tag, "==> printMonth: mm: " + mm + " " + "yy: " + yy);
int trailingSpaces = 0;
int daysInPrevMonth = 0;
int prevMonth = 0;
int prevYear = 0;
int nextMonth = 0;
int nextYear = 0;
int currentMonth = mm - 1;
String currentMonthName = getMonthAsString(currentMonth);
daysInMonth = getNumberOfDaysOfMonth(currentMonth);
Log.d(tag, "Current Month: " + " " + currentMonthName + " having "
+ daysInMonth + " days.");
GregorianCalendar cal = new GregorianCalendar(yy, currentMonth, 1);
Log.d(tag, "Gregorian Calendar:= " + cal.getTime().toString());
if (currentMonth == 11) {
prevMonth = currentMonth - 1;
daysInPrevMonth = getNumberOfDaysOfMonth(prevMonth);
nextMonth = 0;
prevYear = yy;
nextYear = yy + 1;
Log.d(tag, "*->PrevYear: " + prevYear + " PrevMonth:"
+ prevMonth + " NextMonth: " + nextMonth
+ " NextYear: " + nextYear);
} else if (currentMonth == 0) {
prevMonth = 11;
prevYear = yy - 1;
nextYear = yy;
daysInPrevMonth = getNumberOfDaysOfMonth(prevMonth);
nextMonth = 1;
Log.d(tag, "**--> PrevYear: " + prevYear + " PrevMonth:"
+ prevMonth + " NextMonth: " + nextMonth
+ " NextYear: " + nextYear);
} else {
prevMonth = currentMonth - 1;
nextMonth = currentMonth + 1;
nextYear = yy;
prevYear = yy;
daysInPrevMonth = getNumberOfDaysOfMonth(prevMonth);
Log.d(tag, "***---> PrevYear: " + prevYear + " PrevMonth:"
+ prevMonth + " NextMonth: " + nextMonth
+ " NextYear: " + nextYear);
}
int currentWeekDay = cal.get(Calendar.DAY_OF_WEEK) - 1;
trailingSpaces = currentWeekDay;
Log.d(tag, "Week Day:" + currentWeekDay + " is "
+ getWeekDayAsString(currentWeekDay));
Log.d(tag, "No. Trailing space to Add: " + trailingSpaces);
Log.d(tag, "No. of Days in Previous Month: " + daysInPrevMonth);
if (cal.isLeapYear(cal.get(Calendar.YEAR)))
if (mm == 2)
++daysInMonth;
else if (mm == 3)
++daysInPrevMonth;
// Trailing Month days
for (int i = 0; i < trailingSpaces; i++) {
Log.d(tag,
"PREV MONTH:= "
+ prevMonth
+ " => "
+
getMonthAsString(prevMonth)
+ " "
+
String.valueOf((daysInPrevMonth
-
trailingSpaces + DAY_OFFSET)
+ i));
list.add(String
.valueOf((daysInPrevMonth - trailingSpaces
+ DAY_OFFSET)
+ i)
+ "-GREY"
+ "-"
+ getMonthAsString(prevMonth)
+ "-"
+ prevYear);
}
// Current Month Days
for (int i = 1; i <= daysInMonth; i++) {
Log.d(currentMonthName, String.valueOf(i) + " "
+ getMonthAsString(currentMonth) + " " +
yy);
if (i == getCurrentDayOfMonth()) {
list.add(String.valueOf(i) + "-BLUE" + "-"
+ getMonthAsString(currentMonth) +
"-" + yy);
} else {
list.add(String.valueOf(i) + "-WHITE" + "-"
+ getMonthAsString(currentMonth) +
"-" + yy);
}
}
// Leading Month days
for (int i = 0; i < list.size() % 7; i++) {
Log.d(tag, "NEXT MONTH:= " + getMonthAsString(nextMonth));
list.add(String.valueOf(i + 1) + "-GREY" + "-"
+ getMonthAsString(nextMonth) + "-" +
nextYear);
}
}
/**
* NOTE: YOU NEED TO IMPLEMENT THIS PART Given the YEAR, MONTH, retrieve
* ALL entries from a SQLite database for that month. Iterate over the
* List of All entries, and get the dateCreated, which is converted into
* day.
*
* @param year
* @param month
* @return
*/
private HashMap<String, Integer> findNumberOfEventsPerMonth(int year,
int month) {
HashMap<String, Integer> map = new HashMap<String, Integer>();
return map;
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View row = convertView;
if (row == null) {
LayoutInflater inflater = (LayoutInflater) _context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
row = inflater.inflate(R.layout.screen_gridcell, parent,
false);
}
// Get a reference to the Day gridcell
gridcell = (Button) row.findViewById(R.id.calendar_day_gridcell);
gridcell.setOnClickListener(this);
// ACCOUNT FOR SPACING
Log.d(tag, "Current Day: " + getCurrentDayOfMonth());
String[] day_color = list.get(position).split("-");
String theday = day_color[0];
String themonth = day_color[2];
String theyear = day_color[3];
if ((!eventsPerMonthMap.isEmpty()) && (eventsPerMonthMap !=
null)) {
if (eventsPerMonthMap.containsKey(theday)) {
num_events_per_day = (TextView) row
.findViewById(R.id.num_events_per_day);
Integer numEvents = (Integer)
eventsPerMonthMap.get(theday);
num_events_per_day.setText(numEvents.toString());
}
}
// Set the Day GridCell
gridcell.setText(theday);
gridcell.setTag(theday + "-" + themonth + "-" + theyear);
Log.d(tag, "Setting GridCell " + theday + "-" + themonth + "-"
+ theyear);
if (day_color[1].equals("GREY")) {
gridcell.setTextColor(getResources()
.getColor(R.color.lightgray));
}
if (day_color[1].equals("WHITE")) {
gridcell.setTextColor(getResources().getColor(
R.color.lightgray02));
}
if (day_color[1].equals("BLUE")) {
gridcell.setTextColor(getResources().getColor(R.color.orrange));
}
return row;
}
@Override
public void onClick(View view) {
String date_month_year = (String) view.getTag();
selectedDayMonthYearButton.setText("Selected: " + date_month_year);
Log.e("Selected date", date_month_year);
try {
Date parsedDate = dateFormatter.parse(date_month_year);
Log.d(tag, "Parsed Date: " + parsedDate.toString());
} catch (ParseException e) {
e.printStackTrace();
}
}
public int getCurrentDayOfMonth() {
return currentDayOfMonth;
}
private void setCurrentDayOfMonth(int currentDayOfMonth) {
this.currentDayOfMonth = currentDayOfMonth;
}
public void setCurrentWeekDay(int currentWeekDay) {
this.currentWeekDay = currentWeekDay;
}
public int getCurrentWeekDay() {
return currentWeekDay;
}
}
}
public class HorizontalListView extends AdapterView<ListAdapter> {
public boolean mAlwaysOverrideTouch = true;
protected ListAdapter mAdapter;
private int mLeftViewIndex = -1;
private int mRightViewIndex = 0;
protected int mCurrentX;
protected int mNextX;
private int mMaxX = Integer.MAX_VALUE;
private int mDisplayOffset = 0;
protected Scroller mScroller;
private GestureDetector mGesture;
private Queue<View> mRemovedViewQueue = new LinkedList<View>();
private OnItemSelectedListener mOnItemSelected;
private OnItemClickListener mOnItemClicked;
private OnItemLongClickListener mOnItemLongClicked;
private boolean mDataChanged = false;
public HorizontalListView(Context context, AttributeSet attrs) {
super(context, attrs);
initView();
}
private synchronized void initView() {
mLeftViewIndex = -1;
mRightViewIndex = 0;
mDisplayOffset = 0;
mCurrentX = 0;
mNextX = 0;
mMaxX = Integer.MAX_VALUE;
mScroller = new Scroller(getContext());
mGesture = new GestureDetector(getContext(), mOnGesture);
}
@Override
public void setOnItemSelectedListener(AdapterView.OnItemSelectedListener
listener) {
mOnItemSelected = listener;
}
@Override
public void setOnItemClickListener(AdapterView.OnItemClickListener listener){
mOnItemClicked = listener;
}
@Override
public void setOnItemLongClickListener(AdapterView.OnItemLongClickListener
listener) {
mOnItemLongClicked = listener;
}
private DataSetObserver mDataObserver = new DataSetObserver() {
@Override
public void onChanged() {
synchronized(HorizontalListView.this){
mDataChanged = true;
}
invalidate();
requestLayout();
}
@Override
public void onInvalidated() {
reset();
invalidate();
requestLayout();
}
};
@Override
public ListAdapter getAdapter() {
return mAdapter;
}
@Override
public View getSelectedView() {
//TODO: implement
return null;
}
@Override
public void setAdapter(ListAdapter adapter) {
if(mAdapter != null) {
mAdapter.unregisterDataSetObserver(mDataObserver);
}
mAdapter = adapter;
mAdapter.registerDataSetObserver(mDataObserver);
reset();
}
private synchronized void reset(){
initView();
removeAllViewsInLayout();
requestLayout();
}
@Override
public void setSelection(int position) {
//TODO: implement
}
private void addAndMeasureChild(final View child, int viewPos) {
LayoutParams params = child.getLayoutParams();
if(params == null) {
params = new LayoutParams(LayoutParams.FILL_PARENT,
LayoutParams.FILL_PARENT);
}
addViewInLayout(child, viewPos, params, true);
child.measure(MeasureSpec.makeMeasureSpec(getWidth(), MeasureSpec.AT_MOST),
MeasureSpec.makeMeasureSpec(getHeight(),
MeasureSpec.AT_MOST));
}
@Override
protected synchronized void onLayout(boolean changed, int left, int top, int
right, int bottom) {
super.onLayout(changed, left, top, right, bottom);
if(mAdapter == null){
return;
}
if(mDataChanged){
int oldCurrentX = mCurrentX;
initView();
removeAllViewsInLayout();
mNextX = oldCurrentX;
mDataChanged = false;
}
if(mScroller.computeScrollOffset()){
int scrollx = mScroller.getCurrX();
mNextX = scrollx;
}
if(mNextX <= 0){
mNextX = 0;
mScroller.forceFinished(true);
}
if(mNextX >= mMaxX) {
mNextX = mMaxX;
mScroller.forceFinished(true);
}
int dx = mCurrentX - mNextX;
removeNonVisibleItems(dx);
fillList(dx);
positionItems(dx);
mCurrentX = mNextX;
if(!mScroller.isFinished()){
post(new Runnable(){
@Override
public void run() {
requestLayout();
}
});
}
}
private void fillList(final int dx) {
int edge = 0;
View child = getChildAt(getChildCount()-1);
if(child != null) {
edge = child.getRight();
}
fillListRight(edge, dx);
edge = 0;
child = getChildAt(0);
if(child != null) {
edge = child.getLeft();
}
fillListLeft(edge, dx);
}
private void fillListRight(int rightEdge, final int dx) {
while(rightEdge + dx < getWidth() && mRightViewIndex <
mAdapter.getCount()) {
View child = mAdapter.getView(mRightViewIndex,
mRemovedViewQueue.poll(), this);
addAndMeasureChild(child, -1);
rightEdge += child.getMeasuredWidth();
if(mRightViewIndex == mAdapter.getCount()-1) {
mMaxX = mCurrentX + rightEdge - getWidth();
}
if (mMaxX < 0) {
mMaxX = 0;
}
mRightViewIndex++;
}
}
private void fillListLeft(int leftEdge, final int dx) {
while(leftEdge + dx > 0 && mLeftViewIndex >= 0) {
View child = mAdapter.getView(mLeftViewIndex,
mRemovedViewQueue.poll(), this);
addAndMeasureChild(child, 0);
leftEdge -= child.getMeasuredWidth();
mLeftViewIndex--;
mDisplayOffset -= child.getMeasuredWidth();
}
}
private void removeNonVisibleItems(final int dx) {
View child = getChildAt(0);
while(child != null && child.getRight() + dx <= 0) {
mDisplayOffset += child.getMeasuredWidth();
mRemovedViewQueue.offer(child);
removeViewInLayout(child);
mLeftViewIndex++;
child = getChildAt(0);
}
child = getChildAt(getChildCount()-1);
while(child != null && child.getLeft() + dx >= getWidth()) {
mRemovedViewQueue.offer(child);
removeViewInLayout(child);
mRightViewIndex--;
child = getChildAt(getChildCount()-1);
}
}
private void positionItems(final int dx) {
if(getChildCount() > 0){
mDisplayOffset += dx;
int left = mDisplayOffset;
for(int i=0;i<getChildCount();i++){
View child = getChildAt(i);
int childWidth = child.getMeasuredWidth();
child.layout(left, 0, left + childWidth,
child.getMeasuredHeight());
left += childWidth + child.getPaddingRight();
}
}
}
public synchronized void scrollTo(int x) {
mScroller.startScroll(mNextX, 0, x - mNextX, 0);
requestLayout();
}
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
boolean handled = super.dispatchTouchEvent(ev);
handled |= mGesture.onTouchEvent(ev);
return handled;
}
protected boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
float velocityY) {
synchronized(HorizontalListView.this){
mScroller.fling(mNextX, 0, (int)-velocityX, 0, 0, mMaxX, 0, 0);
}
requestLayout();
return true;
}
protected boolean onDown(MotionEvent e) {
mScroller.forceFinished(true);
return true;
}
private OnGestureListener mOnGesture = new
GestureDetector.SimpleOnGestureListener() {
@Override
public boolean onDown(MotionEvent e) {
return HorizontalListView.this.onDown(e);
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
float velocityY) {
return HorizontalListView.this.onFling(e1, e2, velocityX,
velocityY);
}
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2,
float distanceX, float distanceY) {
synchronized(HorizontalListView.this){
mNextX += (int)distanceX;
}
requestLayout();
return true;
}
@Override
public boolean onSingleTapConfirmed(MotionEvent e) {
for(int i=0;i<getChildCount();i++){
View child = getChildAt(i);
if (isEventWithinView(e, child)) {
if(mOnItemClicked != null){
mOnItemClicked.onItemClick(HorizontalListView.this, child, mLeftViewIndex + 1 + i,
mAdapter.getItemId( mLeftViewIndex + 1 + i ));
}
if(mOnItemSelected != null){
mOnItemSelected.onItemSelected(HorizontalListView.this, child, mLeftViewIndex + 1 +
i, mAdapter.getItemId( mLeftViewIndex + 1 + i ));
}
break;
}
}
return true;
}
@Override
public void onLongPress(MotionEvent e) {
int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
View child = getChildAt(i);
if (isEventWithinView(e, child)) {
if (mOnItemLongClicked != null) {
mOnItemLongClicked.onItemLongClick(HorizontalListView.this, child, mLeftViewIndex +
1 + i, mAdapter.getItemId(mLeftViewIndex + 1 + i));
}
break;
}
}
}
private boolean isEventWithinView(MotionEvent e, View child) {
Rect viewRect = new Rect();
int[] childPosition = new int[2];
child.getLocationOnScreen(childPosition);
int left = childPosition[0];
int right = left + child.getWidth();
int top = childPosition[1];
int bottom = top + child.getHeight();
viewRect.set(left, top, right, bottom);
return viewRect.contains((int) e.getRawX(), (int) e.getRawY());
}
};
}