java中如何清除String数组中的所有元素？

Question

由于我尝试动态加载元素，因此我收到 java.util.ConcurrentModificationException ，因此我想清除其中的所有元素。请指导我如何清除元素或如何使用片段以任何其他方式进行操作。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: main
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)

Answer 1

严格回答您的问题：

java.lang.Arrays.fill() 

提供了几种允许您清除数组内容的方法。

这很可能不能解决您的实际问题。 ConcurrentModificationException 与“清除”数组无关。

Answer 2

ConcurrentModificationException 最可能的原因是，当您对 series_value 调用 toArray 时，您会对其进行迭代，同时通过添加来修改它元素。

您应该在每次执行此代码段时创建一个新的 series_value 实例，并且之后不要重复使用该实例。

String Scroll_series[] = new String[]{"     "};      
List<String> series_value = new ArrayList<String>(); // fresh instance
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()]);

Answer 3

堆栈跟踪的这一部分是导致 CME 的关键：

... java.util.ConcurrentModificationException 
... at java.util.LinkedList$LinkIterator.next(LinkedList.java:124)     
... at com.kk.scroll.ScrollView.notifyChangingListeners(ScrollView.java:220)
... at com.kk.scroll.ScrollView.setCurrentItem(ScrollView.java:296)
... at com.kk.SellMyCar.Scroller.initScroll1(Scroller.java:135)
... at com.kk.SellMyCar.Scroller.updateStatus(Scroller.java:117)
...
... at com.kk.scroll.ScrollView.notifyScrollingListenersAboutEnd(
       ScrollView.java:266)

如果您仔细研究ConcurrentModificationException 的 API 文档 您很可能会发现在 initScroll1/2 中添加侦听器是不安全的，因为它会干扰在其中执行的迭代notifyChangingListeners。

使用您提供的代码墙而不是 SSCCE ，很难说出如何解决这个问题，但据我所知可以看到，将 initScroll1/2 从 onCreate 移动到构造函数看起来值得尝试：

public class Scroller extends Activity {
    // ...
    // add constructor that inits scrolls
    public Scroller() {
            initScroll1(R.id.p1);
            initScroll2(R.id.p2);
        }
    // ...
    @Override
    // comment out code that inits scrolls
    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);
            // causes CME: initScroll1(R.id.p1);
            // causes CME: initScroll2(R.id.p2);
            updateStatus();
        }
    // ...