我java.util.ConcurrentModificationException正在尝试动态加载元素，所以我想清除其中的所有元素。请指导我如何清除元素或如何以任何其他方式使用片段。谢谢..
String Scroll_series[] = new String[]{" "};
Cursor c = db.rawQuery("SELECT DISTINCT SERIES FROM CBCTABLE where YEAR=2012 AND MAKE='Audi' AND MODEL='A6'" , null);
if (c != null ) {
if (c.moveToFirst()) {
do {
String SERIES = c.getString(c.getColumnIndex("series"));
series_value.add(SERIES);
}while (c.moveToNext());
}
}
Scroll_series = series_value.toArray(new String[series_value.size()]);
这是我的完整代码。
public class Scroller extends Activity
{
private static final String TAG = "TAG";
// TODO: Externalize string-array
String value_year="";
String value_make="";
String value_model="";
String value_series="";
String value_style="";
String Scroll_year[] = new String[]{"2012", "2011", "2010", "2009", "2008", "2007","2006","2005","2004"};
String Scroll_make[] = new String[]{" "};
protected SQLiteDatabase db;
List<String> year_value = new ArrayList<String>();
List<String> model_value = new ArrayList<String>();
List<String> series_value = new ArrayList<String>();
List<String> style_value = new ArrayList<String>();
// Scroll scrolled flag
private boolean ScrollScrolled = false;
private TextView text;
private EditText text1;
private EditText text2;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.scroller);
SQLiteAdapter helper = new SQLiteAdapter(this);
db = helper.getWritableDatabase();
// drillyear();
// drillmake();
text1 = (EditText) this.findViewById(R.id.r1);
text2 = (EditText) this.findViewById(R.id.r2);
initScroll1(R.id.p1);
initScroll2(R.id.p2);
updateStatus();
}
// Scroll scrolled listener
OnScrollScrollListener scrolledListener = new OnScrollScrollListener()
{
public void onScrollStarts(ScrollView Scroll)
{
ScrollScrolled = true;
}
public void onScrollEnds(ScrollView Scroll)
{
ScrollScrolled = false;
updateStatus();
}
};
// Scroll changed listener
public OnScrollChangedListener changedListener = new OnScrollChangedListener()
{
public void onChanged(ScrollView Scroll, int oldValue, int newValue)
{
if (!ScrollScrolled)
{
updateStatus();
}
}
};
private void updateStatus()
{
text1.setText(Scroll_year[getWheel(R.id.p1).getCurrentItem()]);
text2.setText(Scroll_make[getWheel(R.id.p2).getCurrentItem()]);
value_year = Scroll_year[getWheel(R.id.p1).getCurrentItem()];
value_make = Scroll_make[getWheel(R.id.p2).getCurrentItem()];
initScroll1(R.id.p1);
}
private ScrollView getWheel(int id)
{
return (ScrollView) findViewById(id);
}
private int getWheelValue(int id)
{
return getWheel(id).getCurrentItem();
}
private void initScroll1(int id)
{
ScrollView Scroll = (ScrollView) findViewById(id);
Scroll.setAdapter(new ArrayScrollAdapter<String>(Scroll_year));
Scroll.setVisibleItems(4);
Scroll.setCurrentItem(0);
Scroll.addChangingListener(changedListener);
Scroll.addScrollingListener(scrolledListener);
drillmake();
}
private void initScroll2(int id)
{
ScrollView Scroll = (ScrollView) findViewById(id);
Scroll.setAdapter(new ArrayScrollAdapter<String>(Scroll_make));
Scroll.setVisibleItems(4);
Scroll.setCurrentItem(0);
Scroll.addChangingListener(changedListener);
Scroll.addScrollingListener(scrolledListener);
}
private ScrollView getScroll(int id)
{
return (ScrollView) findViewById(id);
}
private int getScrollValue(int id)
{
return getScroll(id).getCurrentItem();
}
public void drillyear()
{
Cursor c = db.rawQuery("SELECT DISTINCT YEAR FROM CBCTABLE " , null);
if (c != null ) {
if (c.moveToFirst()) {
do {
String YEAR = c.getString(c.getColumnIndex("year"));
Log.v(TAG,YEAR);
//int age = c.getInt(c.getColumnIndex("Age"));
year_value.add(YEAR);
}while (c.moveToNext());
}
}
Scroll_year = year_value.toArray(new String[year_value.size()]);
}
public void drillmake()
{
value_year = Scroll_year[getWheel(R.id.p1).getCurrentItem()];
Cursor c = db.rawQuery("SELECT DISTINCT MAKE FROM CBCTABLE where YEAR="+value_year , null);
List<String> make_value = new ArrayList<String>();
if (c != null ) {
if (c.moveToFirst()) {
do {
String MAKE = c.getString(c.getColumnIndex("make"));
Log.v(TAG,MAKE);
make_value.add(MAKE);
}while (c.moveToNext());
}
}
Scroll_make = make_value.toArray(new String[make_value.size()]);
}
}
我的代码的另一部分
public class ScrollView extends View
{
/** Current value & label text color */
private static final int VALUE_TEXT_COLOR = 0xE0000000;
/** Items text color */
private static final int ITEMS_TEXT_COLOR = 0xFF000000;
/** Top and bottom shadows colors */
private static final int[] SHADOWS_COLORS = new int[]{0xFF111111, 0x00AAAAAA, 0x00AAAAAA};
/** Additional items height (is added to standard text item height) */
private static final int ADDITIONAL_ITEM_HEIGHT = 20;
/** Text size */
private static final int TEXT_SIZE = 19;
/** Top and bottom items offset (to hide that) */
private static final int ITEM_OFFSET = TEXT_SIZE / 2;
/** Additional width for items layout */
private static final int ADDITIONAL_ITEMS_SPACE = 35;
/** Label offset */
private static final int LABEL_OFFSET = 13;
/** Left and right padding value */
private static final int PADDING = 15;
/** Default count of visible items */
private static final int DEF_VISIBLE_ITEMS = 15;
// Scroll Values
private ScrollAdapter adapter = null;
private int currentItem = 0;
// Widths
private int itemsWidth = 0;
private int labelWidth = 0;
// Count of visible items
private int visibleItems = DEF_VISIBLE_ITEMS;
// Text paints
private TextPaint itemsPaint;
private TextPaint valuePaint;
// Layouts
private StaticLayout itemsLayout;
private StaticLayout labelLayout;
private StaticLayout valueLayout;
// Label & background
private String label;
private Drawable centerDrawable;
// Shadows drawables
private GradientDrawable topShadow;
private GradientDrawable bottomShadow;
// Last touch Y position
private float lastYTouch;
// scrolling
private boolean isScrollingPerformed;
// listeners
private final List<OnScrollChangedListener> changingListeners = new LinkedList<OnScrollChangedListener>();
private final List<OnScrollScrollListener> scrollingListeners = new LinkedList<OnScrollScrollListener>();
/**
* Constructor
*/
public ScrollView(Context context, AttributeSet attrs, int defStyle)
{
super(context, attrs, defStyle);
}
/**
* Constructor
*/
public ScrollView(Context context, AttributeSet attrs)
{
super(context, attrs);
}
/**
* Constructor
*/
public ScrollView(Context context)
{
super(context);
}
/**
* Gets Scroll adapter
*
* @return the adapter
*/
public ScrollAdapter getAdapter()
{
return adapter;
}
/**
* Sets whell adapter
*
* @param adapter
* the new Scroll adapter
*/
public void setAdapter(ScrollAdapter adapter)
{
this.adapter = adapter;
invalidate();
}
/**
* Gets count of visible items
*
* @return the count of visible items
*/
public int getVisibleItems()
{
return visibleItems;
}
/**
* Sets count of visible items
*
* @param count
* the new count
*/
public void setVisibleItems(int count)
{
visibleItems = count;
invalidate();
}
/**
* Gets label
*
* @return the label
*/
public String getLabel()
{
return label;
}
/**
* Sets label
*
* @param newLabel
* the label to set
*/
public void setLabel(String newLabel)
{
if (label == null || !label.equals(newLabel))
{
label = newLabel;
labelLayout = null;
invalidate();
}
}
/**
* Adds Scroll changing listener
*
* @param listener
* the listener
*/
public void addChangingListener(OnScrollChangedListener listener)
{
changingListeners.add(listener);
}
/**
* Removes Scroll changing listener
*
* @param listener
* the listener
*/
public void removeChangingListener(OnScrollChangedListener listener)
{
changingListeners.remove(listener);
}
/**
* Notifies changing listeners
*
* @param oldValue
* the old Scroll value
* @param newValue
* the new Scroll value
*/
protected void notifyChangingListeners(int oldValue, int newValue)
{
for (OnScrollChangedListener listener : changingListeners)
{
listener.onChanged(this, oldValue, newValue);
}
}
/**
* Adds Scroll scrolling listener
*
* @param listener
* the listener
*/
public void addScrollingListener(OnScrollScrollListener listener)
{
scrollingListeners.add(listener);
}
/**
* Removes Scroll scrolling listener
*
* @param listener
* the listener
*/
public void removeScrollingListener(OnScrollScrollListener listener)
{
scrollingListeners.remove(listener);
}
/**
* Notifies listeners about starting scrolling
*/
protected void notifyScrollingListenersAboutStart()
{
for (OnScrollScrollListener listener : scrollingListeners)
{
listener.onScrollStarts(this);
}
}
/**
* Notifies listeners about ending scrolling
*/
protected void notifyScrollingListenersAboutEnd()
{
for (OnScrollScrollListener listener : scrollingListeners)
{
listener.onScrollEnds(this);
}
}
/**
* Gets current value
*
* @return the current value
*/
public int getCurrentItem()
{
return currentItem;
}
/**
* Sets the current item
*
* @param index
* the item index
*/
public void setCurrentItem(int index)
{
if (index != currentItem)
{
itemsLayout = null;
valueLayout = null;
int old = currentItem;
currentItem = index;
notifyChangingListeners(old, currentItem);
invalidate();
}
}
/**
* Initializes resources
*/
private void initResourcesIfNecessary()
{
if (itemsPaint == null)
{
itemsPaint = new TextPaint(Paint.ANTI_ALIAS_FLAG | Paint.FAKE_BOLD_TEXT_FLAG);
// itemsPaint.density = getResources().getDisplayMetrics().density;
itemsPaint.setTextSize(TEXT_SIZE);
}
if (valuePaint == null)
{
valuePaint = new TextPaint(Paint.ANTI_ALIAS_FLAG | Paint.FAKE_BOLD_TEXT_FLAG | Paint.DITHER_FLAG);
// valuePaint.density = getResources().getDisplayMetrics().density;
valuePaint.setTextSize(TEXT_SIZE);
valuePaint.setShadowLayer(0.5f, 0, 0.5f, 0xFFFFFFFF);
}
if (centerDrawable == null)
{
centerDrawable = getContext().getResources().getDrawable(R.drawable.wheel_val);
}
if (topShadow == null)
{
topShadow = new GradientDrawable(Orientation.TOP_BOTTOM, SHADOWS_COLORS);
}
if (bottomShadow == null)
{
bottomShadow = new GradientDrawable(Orientation.BOTTOM_TOP, SHADOWS_COLORS);
}
setBackgroundResource(R.drawable.wheel_bg);
}
/**
* Calculates desired height for layout
*
* @param layout
* the source layout
* @return the desired layout height
*/
private int getDesiredHeight(Layout layout)
{
if (layout == null) { return 0; }
int linecount = layout.getLineCount();
int desired = layout.getLineTop(linecount) - ITEM_OFFSET * 2 - ADDITIONAL_ITEM_HEIGHT;
// Check against our minimum height
desired = Math.max(desired, getSuggestedMinimumHeight());
return desired;
}
/**
* Builds text depending on current value
*
* @return the text
*/
private String buildText()
{
ScrollAdapter adapter = getAdapter();
StringBuilder itemsText = new StringBuilder();
int addItems = visibleItems / 2;
for (int i = currentItem - addItems; i < currentItem; i++)
{
if (i >= 0 && adapter != null)
{
String text = adapter.getItem(i);
if (text != null)
{
itemsText.append(text);
}
}
itemsText.append("\n");
}
itemsText.append("\n"); // here will be current value
for (int i = currentItem + 1; i <= currentItem + addItems; i++)
{
if (adapter != null && i < adapter.getItemsCount())
{
String text = adapter.getItem(i);
if (text != null)
{
itemsText.append(text);
}
}
if (i < currentItem + addItems)
{
itemsText.append("\n");
}
}
return itemsText.toString();
}
/**
* Returns the max item length that can be present
*
* @return the max length
*/
private int getMaxTextLength()
{
ScrollAdapter adapter = getAdapter();
if (adapter == null) { return 0; }
int adapterLength = adapter.getMaximumLength();
if (adapterLength > 0) { return adapterLength; }
String maxText = null;
int addItems = visibleItems / 2;
for (int i = Math.max(currentItem - addItems, 0); i < Math.min(currentItem + visibleItems, adapter.getItemsCount()); i++)
{
String text = adapter.getItem(i);
if (text != null && (maxText == null || maxText.length() < text.length()))
{
maxText = text;
}
}
return maxText != null ? maxText.length() : 0;
}
/**
* Calculates control width and creates text layouts
*
* @param widthSize
* the input layout width
* @param mode
* the layout mode
* @return the calculated control width
*/
private int calculateLayoutWidth(int widthSize, int mode)
{
initResourcesIfNecessary();
int width = widthSize;
int maxLength = getMaxTextLength();
if (maxLength > 0)
{
float textWidth = FloatMath.ceil(Layout.getDesiredWidth("0", itemsPaint));
itemsWidth = (int) (maxLength * textWidth);
}
else
{
itemsWidth = 0;
}
itemsWidth += ADDITIONAL_ITEMS_SPACE; // make it some more
labelWidth = 0;
if (label != null && label.length() > 0)
{
labelWidth = (int) FloatMath.ceil(Layout.getDesiredWidth(label, valuePaint));
}
boolean recalculate = false;
if (mode == MeasureSpec.EXACTLY)
{
width = widthSize;
recalculate = true;
}
else
{
width = itemsWidth + labelWidth + 2 * PADDING;
if (labelWidth > 0)
{
width += LABEL_OFFSET;
}
// Check against our minimum width
width = Math.max(width, getSuggestedMinimumWidth());
if (mode == MeasureSpec.AT_MOST && widthSize < width)
{
width = widthSize;
recalculate = true;
}
}
if (recalculate)
{
// recalculate width
int pureWidth = width - LABEL_OFFSET - 2 * PADDING;
if (pureWidth <= 0)
{
itemsWidth = labelWidth = 0;
}
if (labelWidth > 0)
{
double newWidthItems = (double) itemsWidth * pureWidth / (itemsWidth + labelWidth);
itemsWidth = (int) newWidthItems;
labelWidth = pureWidth - itemsWidth;
}
else
{
itemsWidth = pureWidth + LABEL_OFFSET; // no label
}
}
if (itemsWidth > 0)
{
createLayouts(itemsWidth, labelWidth);
}
return width;
}
/**
* Creates layouts
*
* @param widthItems
* width of items layout
* @param widthLabel
* width of label layout
*/
private void createLayouts(int widthItems, int widthLabel)
{
if (itemsLayout == null || itemsLayout.getWidth() > widthItems)
{
itemsLayout = new StaticLayout(buildText(), itemsPaint, widthItems, widthLabel > 0 ? Layout.Alignment.ALIGN_OPPOSITE : Layout.Alignment.ALIGN_CENTER, 1, ADDITIONAL_ITEM_HEIGHT, false);
}
else
{
itemsLayout.increaseWidthTo(widthItems);
}
if (valueLayout == null || valueLayout.getWidth() > widthItems)
{
String text = getAdapter() != null ? getAdapter().getItem(currentItem) : null;
valueLayout = new StaticLayout(text != null ? text : "", valuePaint, widthItems, widthLabel > 0 ? Layout.Alignment.ALIGN_OPPOSITE : Layout.Alignment.ALIGN_CENTER, 1, ADDITIONAL_ITEM_HEIGHT, false);
}
else
{
valueLayout.increaseWidthTo(widthItems);
}
if (widthLabel > 0)
{
if (labelLayout == null || labelLayout.getWidth() > widthLabel)
{
labelLayout = new StaticLayout(label, valuePaint, widthLabel, Layout.Alignment.ALIGN_NORMAL, 1, ADDITIONAL_ITEM_HEIGHT, false);
}
else
{
labelLayout.increaseWidthTo(widthLabel);
}
}
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
int widthMode = MeasureSpec.getMode(widthMeasureSpec);
int heightMode = MeasureSpec.getMode(heightMeasureSpec);
int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int heightSize = MeasureSpec.getSize(heightMeasureSpec);
int width = calculateLayoutWidth(widthSize, widthMode);
int height;
if (heightMode == MeasureSpec.EXACTLY)
{
height = heightSize;
}
else
{
height = getDesiredHeight(itemsLayout);
if (heightMode == MeasureSpec.AT_MOST)
{
height = Math.min(height, heightSize);
}
}
setMeasuredDimension(width, height);
}
@Override
protected void onDraw(Canvas canvas)
{
super.onDraw(canvas);
if (itemsLayout == null)
{
if (itemsWidth == 0)
{
calculateLayoutWidth(getWidth(), MeasureSpec.EXACTLY);
}
else
{
createLayouts(itemsWidth, labelWidth);
}
}
drawCenterRect(canvas);
if (itemsWidth > 0)
{
canvas.save();
// Skip padding space and hide a part of top and bottom items
canvas.translate(PADDING, -ITEM_OFFSET);
drawItems(canvas);
drawValue(canvas);
canvas.restore();
}
drawShadows(canvas);
}
/**
* Draws shadows on top and bottom of control
*
* @param canvas
* the canvas for drawing
*/
private void drawShadows(Canvas canvas)
{
topShadow.setBounds(0, 0, getWidth(), getHeight() / visibleItems);
topShadow.draw(canvas);
bottomShadow.setBounds(0, getHeight() - getHeight() / visibleItems, getWidth(), getHeight());
bottomShadow.draw(canvas);
}
/**
* Draws value and label layout
*
* @param canvas
* the canvas for drawing
*/
private void drawValue(Canvas canvas)
{
valuePaint.setColor(VALUE_TEXT_COLOR);
valuePaint.drawableState = getDrawableState();
Rect bounds = new Rect();
itemsLayout.getLineBounds(visibleItems / 2, bounds);
// draw label
if (labelLayout != null)
{
canvas.save();
canvas.translate(itemsLayout.getWidth() + LABEL_OFFSET, bounds.top);
labelLayout.draw(canvas);
canvas.restore();
}
// draw current value
canvas.save();
canvas.translate(0, bounds.top);
valueLayout.draw(canvas);
canvas.restore();
}
/**
* Draws items
*
* @param canvas
* the canvas for drawing
*/
private void drawItems(Canvas canvas)
{
itemsPaint.setColor(ITEMS_TEXT_COLOR);
itemsPaint.drawableState = getDrawableState();
itemsLayout.draw(canvas);
}
/**
* Draws rect for current value
*
* @param canvas
* the canvas for drawing
*/
private void drawCenterRect(Canvas canvas)
{
int center = getHeight() / 2;
int offset = getHeight() / visibleItems / 2;
centerDrawable.setBounds(0, center - offset, getWidth(), center + offset);
centerDrawable.draw(canvas);
}
@Override
public boolean onTouchEvent(MotionEvent event)
{
ScrollAdapter adapter = getAdapter();
if (adapter == null) { return true; }
switch (event.getAction())
{
case MotionEvent.ACTION_DOWN :
lastYTouch = event.getY();
break;
case MotionEvent.ACTION_MOVE :
if (!isScrollingPerformed)
{
isScrollingPerformed = true;
notifyScrollingListenersAboutStart();
}
float delta = event.getY() - lastYTouch;
int count = (int) (visibleItems * delta / getHeight());
int pos = currentItem - count;
pos = Math.max(pos, 0);
pos = Math.min(pos, adapter.getItemsCount() - 1);
if (pos != currentItem)
{
lastYTouch = event.getY();
setCurrentItem(pos);
}
break;
case MotionEvent.ACTION_UP :
if (isScrollingPerformed)
{
notifyScrollingListenersAboutEnd();
isScrollingPerformed = false;
}
break;
}
return true;
}
}
这是我的登录执行
12-21 10:43:26.174：E/AndroidRuntime(591)：致命异常：主要
12-21 10:43:26.174：E/AndroidRuntime(591)：java.util.ConcurrentModificationException
12-21 10:43:26.174: E/AndroidRuntime(591): at java.util.LinkedList$LinkIterator.next(LinkedList.java:124)
12-21 10:43:26.174: E/AndroidRuntime(591): at com.kk.scroll.ScrollView.notifyChangingListeners(ScrollView.java:220)
12-21 10:43:26.174: E/AndroidRuntime(591): at com.kk.scroll.ScrollView.setCurrentItem(ScrollView.java:296)
12-21 10:43:26.174: E/AndroidRuntime(591): at com.kk.SellMyCar.Scroller.initScroll1(Scroller.java:135)
12-21 10:43:26.174: E/AndroidRuntime(591): at com.kk.SellMyCar.Scroller.updateStatus(Scroller.java:117)
12-21 10:43:26.174: E/AndroidRuntime(591): at com.kk.SellMyCar.Scroller.access$1(Scroller.java:109)
12-21 10:43:26.174: E/AndroidRuntime(591): at com.kk.SellMyCar.Scroller$1.onScrollEnds(Scroller.java:91)
12-21 10:43:26.174: E/AndroidRuntime(591): at com.kk.scroll.ScrollView.notifyScrollingListenersAboutEnd(ScrollView.java:266)
12-21 10:43:26.174: E/AndroidRuntime(591): at com.kk.scroll.ScrollView.onTouchEvent(ScrollView.java:722)
12-21 10:43:26.174: E/AndroidRuntime(591): at android.view.View.dispatchTouchEvent(View.java:3766)
12-21 10:43:26.174: E/AndroidRuntime(591): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
12-21 10:43:26.174: E/AndroidRuntime(591): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
12-21 10:43:26.174: E/AndroidRuntime(591): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
12-21 10:43:26.174: E/AndroidRuntime(591): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
12-21 10:43:26.174: E/AndroidRuntime(591): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
12-21 10:43:26.174: E/AndroidRuntime(591): at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1671)
12-21 10:43:26.174: E/AndroidRuntime(591): at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1107)
12-21 10:43:26.174: E/AndroidRuntime(591): at android.app.Activity.dispatchTouchEvent(Activity.java:2086)
12-21 10:43:26.174: E/AndroidRuntime(591): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1655)
12-21 10:43:26.174: E/AndroidRuntime(591): at android.view.ViewRoot.handleMessage(ViewRoot.java:1785)
12-21 10:43:26.174: E/AndroidRuntime(591): at android.os.Handler.dispatchMessage(Handler.java:99)
12-21 10:43:26.174: E/AndroidRuntime(591): at android.os.Looper.loop(Looper.java:123)
12-21 10:43:26.174: E/AndroidRuntime(591): at android.app.ActivityThread.main(ActivityThread.java:4627)
12-21 10:43:26.174: E/AndroidRuntime(591): at java.lang.reflect.Method.invokeNative(Native Method)
12-21 10:43:26.174: E/AndroidRuntime(591): at java.lang.reflect.Method.invoke(Method.java:521)
12-21 10:43:26.174: E/AndroidRuntime(591): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
12-21 10:43:26.174: E/AndroidRuntime(591): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
12-21 10:43:26.174: E/AndroidRuntime(591): at dalvik.system.NativeStart.main(Native Method)