Android：三级城市联动控件

import android.content.Context;import android.content.Intent;import android.os.Bundle;import android.view.Display;import android.view.Gravity;import android.view.View;import android.view.View.OnClickListener;import android.view.ViewGroup;import android.view.WindowManager;import android.widget.Button;import android.widget.TextView;import com...Contants;import com...R;import com...domain.AdressInfo;import com...ui.activity.LotteryBaseActivity;import com...ui.widget.wheel.AbstractWheelTextAdapter;import com...ui.widget.wheel.OnWheelChangedListener;import com...ui.widget.wheel.WheelView;import java.util.ArrayList;/** * 归属地选择对话框 */public class AdressDialog extends LotteryBaseActivity implements OnClickListener {    private WheelView mProvinceWv, mCityWv, mCountyWv;    private ArrayWheelAdapter mProvinceAdapter, mCityAdapter, mCountyAdapter;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.adressdialog);        Button cancelBtn = (Button) findViewById(R.id.btn_adressdialog_cancel);        cancelBtn.setOnClickListener(this);        Button okBtn = (Button) findViewById(R.id.btn_adressdialog_ok);        okBtn.setOnClickListener(this);        WindowManager m = getWindowManager();        Display d = m.getDefaultDisplay();        android.view.WindowManager.LayoutParams p = getWindow().getAttributes();        p.y = 0;        p.width = d.getWidth();        p.gravity = Gravity.BOTTOM;        getWindow().setAttributes(p);        String fullname = getIntent().getStringExtra("fullname");        mProvinceWv = (WheelView) findViewById(R.id.wv_adressdialog_province);        mProvinceWv.setVisibleItems(5);        mProvinceWv.setShowLeftLine(true);        mProvinceAdapter = new ArrayWheelAdapter(this, mAdressDao.getProvinces());        mProvinceWv.setViewAdapter(mProvinceAdapter);        mProvinceWv.setCyclic(true);        mProvinceWv.addChangingListener(new OnWheelChangedListener() {            public void onChanged(WheelView wheel, int oldValue, int newValue) {                mCityAdapter = new ArrayWheelAdapter(AdressDialog.this, mAdressDao.getCitys(mProvinceAdapter.getId(mProvinceWv.getCurrentItem())));                mCityWv.setViewAdapter(mCityAdapter);                mCityWv.setCurrentItem(mCityAdapter.getItemsCount() / 2);            }        });        mCityWv = (WheelView) findViewById(R.id.wv_adressdialog_city);        mCityWv.setVisibleItems(5);        mCityWv.setShowLeftLine(false);        mCityAdapter = new ArrayWheelAdapter(this, mAdressDao.getCitys(mProvinceAdapter.getId(mProvinceWv.getCurrentItem())));        mCityWv.setViewAdapter(mCityAdapter);        mCityWv.setCyclic(true);        mCityWv.addChangingListener(new OnWheelChangedListener() {            public void onChanged(WheelView wheel, int oldValue, int newValue) {                mCountyAdapter = new ArrayWheelAdapter(AdressDialog.this, mAdressDao.getCountys(mCityAdapter.getId(mCityWv.getCurrentItem())));                mCountyWv.setViewAdapter(mCountyAdapter);                mCountyWv.setCurrentItem(mCountyAdapter.getItemsCount() / 2);            }        });        mCountyWv = (WheelView) findViewById(R.id.wv_adressdialog_county);        mCountyWv.setVisibleItems(5);        mCountyWv.setShowLeftLine(false);        mCountyAdapter = new ArrayWheelAdapter(this, mAdressDao.getCountys(mCityAdapter.getId(mCityWv.getCurrentItem())));        mCountyWv.setViewAdapter(mCountyAdapter);        mCountyWv.setCyclic(true);        mProvinceWv.setCurrentItem(mProvinceAdapter.getItemsCount() / 2);        mCityWv.setCurrentItem(mCityAdapter.getItemsCount() / 2);        mCountyWv.setCurrentItem(mCountyAdapter.getItemsCount() / 2);    }    @Override    public void onClick(View v) {        switch (v.getId()) {            case R.id.btn_adressdialog_cancel:                finish();                break;            case R.id.btn_adressdialog_ok:                String province = mProvinceAdapter.getItemText(mProvinceWv.getCurrentItem()).toString();                String city = mCityAdapter.getItemText(mCityWv.getCurrentItem()).toString();                String county = mCountyAdapter.getItemText(mCountyWv.getCurrentItem()).toString();                String countyFullname = mCountyAdapter.getItemFullname(mCountyWv.getCurrentItem()).toString();                Intent data = new Intent();                data.putExtra("adressName", province + "　" + city + "　" + county);                data.putExtra("fullname", countyFullname);                data.putExtra("adressId", mCountyAdapter.getCode(mCountyWv.getCurrentItem()));                setResult(Contants.ACTIVITY_CODE_ADRESS, data);                finish();                break;        }    }    /**     * 滑动内容adapter     */    private class ArrayWheelAdapter extends AbstractWheelTextAdapter {        private ArrayList<AdressInfo> infos = new ArrayList<AdressInfo>();        public int getPositionByName(String adress) {            int len = infos.size();            for (int i = 0; i < len; i++) {                if (adress.equals(infos.get(i).name)) {                    return i;                }            }            return 0;        }        protected ArrayWheelAdapter(Context context) {            super(context, R.layout.adressdialog_item, NO_RESOURCE);        }        public ArrayWheelAdapter(Context context, ArrayList<AdressInfo> infos) {            super(context, R.layout.adressdialog_item, NO_RESOURCE);            this.infos = infos;        }        @Override        public View getItem(int position, View cachedView, ViewGroup parent) {            View view = super.getItem(position, cachedView, parent);            TextView tv = (TextView) view.findViewById(R.id.tv_adressdialog_item);            tv.setText(infos.get(position).name);            return view;        }        @Override        public int getItemsCount() {            return infos.size();        }        @Override        protected CharSequence getItemText(int position) {            if (infos.size() > 0 && position < infos.size()) {                return infos.get(position).name;            }            return "";        }        public String getItemFullname(int position) {            if (infos.size() > 0 && position < infos.size()) {                return infos.get(position).fullname;            }            return "";        }        public long getId(int position) {            if (infos.size() > 0 && position < infos.size()) {                return infos.get(position).id;            }            return 0;        }        public long getCode(int position) {            if (infos.size() > 0 && position < infos.size()) {                return infos.get(position).code;            }            return 0;        }    }}

adressdialog.xml文件：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:background="#f0f0f0"    android:orientation="vertical" >    <RelativeLayout        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:paddingBottom="5dp"        android:paddingLeft="15dp"        android:paddingRight="15dp"        android:paddingTop="5dp" >        <Button            android:id="@+id/btn_adressdialog_cancel"            android:layout_width="60dp"            android:layout_height="40dp"            android:layout_alignParentLeft="true"            android:layout_centerVertical="true"            android:background="@drawable/edit_bg"            android:gravity="center"            android:text="取消"            android:textColor="#5f5f5f"            android:textSize="16dp" />        <Button            android:id="@+id/btn_adressdialog_ok"            android:layout_width="60dp"            android:layout_height="40dp"            android:layout_alignParentRight="true"            android:layout_centerVertical="true"            android:background="@drawable/btn_red_round_rectangle_selector"            android:gravity="center"            android:text="确定"            android:textColor="#fdffff"            android:textSize="16dp" />    </RelativeLayout>    <View        android:layout_width="match_parent"        android:layout_height="1dp"        android:background="#d7d9dc" />    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:orientation="horizontal"        android:weightSum="3" >        <com.dacai.main.ui.widget.wheel.WheelView            android:id="@+id/wv_adressdialog_province"            android:layout_width="0dp"            android:layout_height="wrap_content"            android:layout_weight="1" />        <View            android:layout_width="1dp"            android:layout_height="match_parent"            android:background="#d7d9dc" />        <com.dacai.main.ui.widget.wheel.WheelView            android:id="@+id/wv_adressdialog_city"            android:layout_width="0dp"            android:layout_height="wrap_content"            android:layout_weight="1" />        <View             android:layout_width="1dp"            android:layout_height="match_parent"            android:background="#d7d9dc" />        <com.dacai.main.ui.widget.wheel.WheelView            android:id="@+id/wv_adressdialog_county"            android:layout_width="0dp"            android:layout_height="wrap_content"            android:layout_weight="1" />    </LinearLayout></LinearLayout>

package com...ui.widget.wheel;import java.util.LinkedList;import java.util.List;import android.content.Context;import android.database.DataSetObserver;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.drawable.Drawable;import android.graphics.drawable.GradientDrawable;import android.graphics.drawable.GradientDrawable.Orientation;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.View;import android.view.ViewGroup.LayoutParams;import android.view.animation.Interpolator;import android.widget.LinearLayout;import com...R;import com...utils.CommonUtil;
/**此类在开源的基础上做了一些修改**/public class WheelView extends View {    private int[] SHADOWS_COLORS = new int[]{0xefE9E9E9, 0xcfE9E9E9, 0x3fE9E9E9};    private final int ITEM_OFFSET_PERCENT = 0;    private final int PADDING = 10;    private final int DEF_VISIBLE_ITEMS = 5;    private int currentItem = 0;    private int visibleItems = DEF_VISIBLE_ITEMS;    private int itemHeight = 0;    private Drawable centerDrawable;    private int wheelBackground = 0;    private int wheelForeground = R.drawable.adressdialog_select;    private GradientDrawable topShadow;    private GradientDrawable bottomShadow;    private boolean drawShadows = true;    private WheelScroller scroller;    private boolean isScrollingPerformed;    private int scrollingOffset;    boolean isCyclic = false;    private LinearLayout itemsLayout;    private int firstItem;    private WheelViewAdapter viewAdapter;    private WheelRecycle recycle = new WheelRecycle(this);    private List<OnWheelChangedListener> changingListeners = new LinkedList<OnWheelChangedListener>();    private List<OnWheelScrollListener> scrollingListeners = new LinkedList<OnWheelScrollListener>();    private boolean isShowLeftLine;    private Context context;    public WheelView(Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);        initData(context);    }    public WheelView(Context context, AttributeSet attrs) {        super(context, attrs);        initData(context);    }    public WheelView(Context context) {        super(context);        initData(context);    }    private void initData(Context context) {        this.context = context;        scroller = new WheelScroller(getContext(), scrollingListener);    }    public void setShowLeftLine(boolean isShowLeftLine) {        this.isShowLeftLine = isShowLeftLine;    }    WheelScroller.ScrollingListener scrollingListener = new WheelScroller.ScrollingListener() {        @Override        public void onStarted() {            isScrollingPerformed = true;            notifyScrollingListenersAboutStart();        }        @Override        public void onScroll(int distance) {            doScroll(distance);            int height = getHeight();            if (scrollingOffset > height) {                scrollingOffset = height;                scroller.stopScrolling();            } else if (scrollingOffset < -height) {                scrollingOffset = -height;                scroller.stopScrolling();            }        }        @Override        public void onFinished() {            if (isScrollingPerformed) {                notifyScrollingListenersAboutEnd();                isScrollingPerformed = false;            }            scrollingOffset = 0;            invalidate();        }        @Override        public void onJustify() {            if (Math.abs(scrollingOffset) > WheelScroller.MIN_DELTA_FOR_SCROLLING) {                scroller.scroll(scrollingOffset, 0);            }        }    };    public void setInterpolator(Interpolator interpolator) {        scroller.setInterpolator(interpolator);    }    public int getVisibleItems() {        return visibleItems;    }    public void setVisibleItems(int count) {        visibleItems = count;    }    public WheelViewAdapter getViewAdapter() {        return viewAdapter;    }    private DataSetObserver dataObserver = new DataSetObserver() {        @Override        public void onChanged() {            invalidateWheel(false);        }        @Override        public void onInvalidated() {            invalidateWheel(true);        }    };    public void setViewAdapter(WheelViewAdapter viewAdapter) {        if (this.viewAdapter != null) {            this.viewAdapter.unregisterDataSetObserver(dataObserver);        }        this.viewAdapter = viewAdapter;        if (this.viewAdapter != null) {            this.viewAdapter.registerDataSetObserver(dataObserver);        }        invalidateWheel(true);    }    public void addChangingListener(OnWheelChangedListener listener) {        changingListeners.add(listener);    }    public void removeChangingListener(OnWheelChangedListener listener) {        changingListeners.remove(listener);    }    protected void notifyChangingListeners(int oldValue, int newValue) {        for (OnWheelChangedListener listener : changingListeners) {            listener.onChanged(this, oldValue, newValue);        }    }    public void addScrollingListener(OnWheelScrollListener listener) {        scrollingListeners.add(listener);    }    public void removeScrollingListener(OnWheelScrollListener listener) {        scrollingListeners.remove(listener);    }    protected void notifyScrollingListenersAboutStart() {        for (OnWheelScrollListener listener : scrollingListeners) {            listener.onScrollingStarted(this);        }    }    protected void notifyScrollingListenersAboutEnd() {        for (OnWheelScrollListener listener : scrollingListeners) {            listener.onScrollingFinished(this);        }    }    public int getCurrentItem() {        return currentItem;    }    public void setCurrentItem(int index, boolean animated) {        if (viewAdapter == null || viewAdapter.getItemsCount() == 0) {            return;        }        int itemCount = viewAdapter.getItemsCount();        if (index < 0 || index >= itemCount) {            if (isCyclic) {                while (index < 0) {                    index += itemCount;                }                index %= itemCount;            } else {                return;            }        }        if (index != currentItem) {            if (animated) {                int itemsToScroll = index - currentItem;                if (isCyclic) {                    int scroll = itemCount + Math.min(index, currentItem) - Math.max(index, currentItem);                    if (scroll < Math.abs(itemsToScroll)) {                        itemsToScroll = itemsToScroll < 0 ? scroll : -scroll;                    }                }                scroll(itemsToScroll, 0);            } else {                scrollingOffset = 0;                int old = currentItem;                currentItem = index;                notifyChangingListeners(old, currentItem);                invalidate();            }        }    }    public void setCurrentItem(int index) {        setCurrentItem(index, false);    }    public boolean isCyclic() {        return isCyclic;    }    public void setCyclic(boolean isCyclic) {        this.isCyclic = isCyclic;        invalidateWheel(false);    }    public boolean drawShadows() {        return drawShadows;    }    public void setDrawShadows(boolean drawShadows) {        this.drawShadows = drawShadows;    }    public void setShadowColor(int start, int middle, int end) {        SHADOWS_COLORS = new int[]{start, middle, end};    }    public void setWheelBackground(int resource) {        wheelBackground = resource;        setBackgroundResource(wheelBackground);    }    public void setWheelForeground(int resource) {        wheelForeground = resource;        centerDrawable = getContext().getResources().getDrawable(wheelForeground);    }    public void invalidateWheel(boolean clearCaches) {        if (clearCaches) {            recycle.clearAll();            if (itemsLayout != null) {                itemsLayout.removeAllViews();            }            scrollingOffset = 0;        } else if (itemsLayout != null) {            recycle.recycleItems(itemsLayout, firstItem, new ItemsRange());        }        invalidate();    }    private void initResourcesIfNecessary() {        if (centerDrawable == null) {            centerDrawable = getContext().getResources().getDrawable(wheelForeground);        }        if (topShadow == null) {            topShadow = new GradientDrawable(Orientation.TOP_BOTTOM, SHADOWS_COLORS);        }        if (bottomShadow == null) {            bottomShadow = new GradientDrawable(Orientation.BOTTOM_TOP, SHADOWS_COLORS);        }        setBackgroundResource(wheelBackground);    }    private int getDesiredHeight(LinearLayout layout) {        if (layout != null && layout.getChildAt(0) != null) {            itemHeight = layout.getChildAt(0).getMeasuredHeight();        }        int desired = itemHeight * visibleItems - itemHeight * ITEM_OFFSET_PERCENT / 50;        return Math.max(desired, getSuggestedMinimumHeight());    }    private int getItemHeight() {        if (itemHeight != 0) {            return itemHeight;        }        if (itemsLayout != null && itemsLayout.getChildAt(0) != null) {            itemHeight = itemsLayout.getChildAt(0).getHeight();            return itemHeight;        }        return getHeight() / visibleItems;    }    private int calculateLayoutWidth(int widthSize, int mode) {        initResourcesIfNecessary();        itemsLayout.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));        itemsLayout.measure(MeasureSpec.makeMeasureSpec(widthSize, MeasureSpec.UNSPECIFIED), MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));        int width = itemsLayout.getMeasuredWidth();        if (mode == MeasureSpec.EXACTLY) {            width = widthSize;        } else {            width += 2 * PADDING;            width = Math.max(width, getSuggestedMinimumWidth());            if (mode == MeasureSpec.AT_MOST && widthSize < width) {                width = widthSize;            }        }        itemsLayout.measure(MeasureSpec.makeMeasureSpec(width - 2 * PADDING, MeasureSpec.EXACTLY), MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));        return width;    }    @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);        buildViewForMeasuring();        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 onLayout(boolean changed, int l, int t, int r, int b) {        layout(r - l, b - t);    }    private void layout(int width, int height) {        int itemsWidth = width - 2 * PADDING;        itemsLayout.layout(0, 0, itemsWidth, height);    }    @Override    protected void onDraw(Canvas canvas) {        super.onDraw(canvas);        if (viewAdapter != null && viewAdapter.getItemsCount() > 0) {            updateView();            drawItems(canvas);            drawCenterRect(canvas);        }        if (drawShadows) drawShadows(canvas);    }    private void drawShadows(Canvas canvas) {        int height = CommonUtil.convertDipOrPx(context, 26);        topShadow.setBounds(0, 0, getWidth(), height);        topShadow.draw(canvas);        bottomShadow.setBounds(0, getHeight() - height, getWidth(), getHeight());        bottomShadow.draw(canvas);    }    private void drawItems(Canvas canvas) {        canvas.save();        int top = (currentItem - firstItem) * getItemHeight() + (getItemHeight() - getHeight()) / 2;        canvas.translate(PADDING, -top + scrollingOffset);        itemsLayout.draw(canvas);        canvas.restore();    }    private void drawCenterRect(Canvas canvas) {        int center = getHeight() / 2;        int offset = (int) (getItemHeight() / 2 * 1.2);        Paint paint = new Paint();        paint.setColor(Color.parseColor("#d7d9dc"));        paint.setStrokeWidth((float) CommonUtil.convertDipOrPx(context, 1));        canvas.drawLine(0, center - offset, getWidth(), center - offset, paint);        canvas.drawLine(0, center + offset, getWidth(), center + offset, paint);        if(isShowLeftLine){            Paint leftPaint = new Paint();            leftPaint.setColor(context.getResources().getColor(R.color.theme_red));            canvas.drawRect(0, center - offset, CommonUtil.convertDipOrPx(context, 4), center + offset, leftPaint);        }    }    @Override    public boolean onTouchEvent(MotionEvent event) {        if (!isEnabled() || getViewAdapter() == null) {            return true;        }        switch (event.getAction()) {            case MotionEvent.ACTION_MOVE:                if (getParent() != null) {                    getParent().requestDisallowInterceptTouchEvent(true);                }                break;            case MotionEvent.ACTION_UP:                if (!isScrollingPerformed) {                    int distance = (int) event.getY() - getHeight() / 2;                    if (distance > 0) {                        distance += getItemHeight() / 2;                    } else {                        distance -= getItemHeight() / 2;                    }                    int items = distance / getItemHeight();                }                break;        }        return scroller.onTouchEvent(event);    }    private void doScroll(int delta) {        scrollingOffset += delta;        int itemHeight = getItemHeight();        int count = scrollingOffset / itemHeight;        int pos = currentItem - count;        int itemCount = viewAdapter.getItemsCount();        int fixPos = scrollingOffset % itemHeight;        if (Math.abs(fixPos) <= itemHeight / 2) {            fixPos = 0;        }        if (isCyclic && itemCount > 0) {            if (fixPos > 0) {                pos--;                count++;            } else if (fixPos < 0) {                pos++;                count--;            }            while (pos < 0) {                pos += itemCount;            }            pos %= itemCount;        } else {            if (pos < 0) {                count = currentItem;                pos = 0;            } else if (pos >= itemCount) {                count = currentItem - itemCount + 1;                pos = itemCount - 1;            } else if (pos > 0 && fixPos > 0) {                pos--;                count++;            } else if (pos < itemCount - 1 && fixPos < 0) {                pos++;                count--;            }        }        int offset = scrollingOffset;        if (pos != currentItem) {            if (pos > itemCount - 1) {                pos = itemCount - 1;            }            if (pos < 0) {                pos = 0;            }            setCurrentItem(pos, false);        } else {            invalidate();        }        scrollingOffset = offset - count * itemHeight;        if (scrollingOffset > getHeight()) {            scrollingOffset = scrollingOffset % getHeight() + getHeight();        }    }    public void scroll(int itemsToScroll, int time) {        int distance = itemsToScroll * getItemHeight() - scrollingOffset;        scroller.scroll(distance, time);    }    private ItemsRange getItemsRange() {        if (getItemHeight() == 0) {            return null;        }        int first = currentItem;        int count = 1;        while (count * getItemHeight() < getHeight()) {            first--;            count += 2;        }        if (scrollingOffset != 0) {            if (scrollingOffset > 0) {                first--;            }            count++;            int emptyItems = scrollingOffset / getItemHeight();            first -= emptyItems;            count += Math.asin(emptyItems);        }        return new ItemsRange(first, count);    }    private boolean rebuildItems() {        boolean updated = false;        ItemsRange range = getItemsRange();        if (itemsLayout != null) {            int first = recycle.recycleItems(itemsLayout, firstItem, range);            updated = firstItem != first;            firstItem = first;        } else {            createItemsLayout();            updated = true;        }        if (!updated) {            updated = firstItem != range.getFirst() || itemsLayout.getChildCount() != range.getCount();        }        if (firstItem > range.getFirst() && firstItem <= range.getLast()) {            for (int i = firstItem - 1; i >= range.getFirst(); i--) {                if (!addViewItem(i, true)) {                    break;                }                firstItem = i;            }        } else {            firstItem = range.getFirst();        }        int first = firstItem;        for (int i = itemsLayout.getChildCount(); i < range.getCount(); i++) {            if (!addViewItem(firstItem + i, false) && itemsLayout.getChildCount() == 0) {                first++;            }        }        firstItem = first;        return updated;    }    private void updateView() {        if (rebuildItems()) {            calculateLayoutWidth(getWidth(), MeasureSpec.EXACTLY);            layout(getWidth(), getHeight());        }    }    private void createItemsLayout() {        if (itemsLayout == null) {            itemsLayout = new LinearLayout(getContext());            itemsLayout.setOrientation(LinearLayout.VERTICAL);        }    }    private void buildViewForMeasuring() {        if (itemsLayout != null) {            recycle.recycleItems(itemsLayout, firstItem, new ItemsRange());        } else {            createItemsLayout();        }        int addItems = visibleItems / 2;        for (int i = currentItem + addItems; i >= currentItem - addItems; i--) {            if (addViewItem(i, true)) {                firstItem = i;            }        }    }    private boolean addViewItem(int index, boolean first) {        View view = getItemView(index);        if (view != null) {            if (first) {                itemsLayout.addView(view, 0);            } else {                itemsLayout.addView(view);            }            return true;        }        return false;    }    private boolean isValidItemIndex(int index) {        return viewAdapter != null && viewAdapter.getItemsCount() > 0 && (isCyclic || index >= 0 && index < viewAdapter.getItemsCount());    }    private View getItemView(int index) {        if (viewAdapter == null || viewAdapter.getItemsCount() == 0) {            return null;        }        int count = viewAdapter.getItemsCount();        if (!isValidItemIndex(index)) {            return viewAdapter.getEmptyItem(recycle.getEmptyItem(), itemsLayout);        } else {            while (index < 0) {                index = count + index;            }        }        index %= count;        return viewAdapter.getItem(index, recycle.getItem(), itemsLayout);    }    public void stopScrolling() {        scroller.stopScrolling();    }}
效果图：