仿Iphone时间选择滑动控件：

WheelView.java:

/** * @author Administrator *  * 时间滑动滚轮 */public class WheelView extends View{    /** 手势监听控件  **/    private GestureDetector gestureDetector;    /** 滑动管理类   **/    private Scroller scroller;    /** 适配器  **/    private WheelAdapter adapter;        private StaticLayout itemsLayout;    private StaticLayout labelLayout;    private StaticLayout valueLayout;        /** 滑动偏移量   **/    private int scrollingOffset;    /** 当前的Item **/    private int currentItem = 0;        /** 默认的可见的Item个数   **/    private static final int DEF_VISIBLE_ITEMS = 5;    private int visibleItems = DEF_VISIBLE_ITEMS;        /** 标签  **/    private String label;    /** 图片  **/    private Drawable centerDrawable;    /** 是否回收  **/    private boolean isCyclic = false;        private List
     
       changingListeners = new LinkedList
      
       ();    private List
       
         scrollingListeners = new LinkedList
        
         ();        /** 滑动的频率  **/    private static final int SCROLLING_DURATION = 400;    /** 文字大小  */    private static final int TEXT_SIZE = 24;        private TextPaint itemsPaint;    private TextPaint valuePaint;        private GradientDrawable topShadow;    private GradientDrawable bottomShadow;    private static final int[] SHADOWS_COLORS = new int[] { 0xFF111111,        0x00AAAAAA, 0x00AAAAAA };        private static final int ITEM_OFFSET = TEXT_SIZE / 5;    private static final int ADDITIONAL_ITEM_HEIGHT = 15;    private static final int LABEL_OFFSET = 8;    private static final int ADDITIONAL_ITEMS_SPACE = 10;    private static final int PADDING = 10;        private int itemHeight = 0;    private int itemsWidth = 0;    private int labelWidth = 0;        private int lastScrollY;        // Messages    private final int MESSAGE_SCROLL = 0;    private final int MESSAGE_JUSTIFY = 1;        private boolean isScrollingPerformed;     private static final int MIN_DELTA_FOR_SCROLLING = 1;        private static final int ITEMS_TEXT_COLOR = 0xFF000000;    private static final int VALUE_TEXT_COLOR = 0xF0000000;        public WheelView(Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);        // TODO Auto-generated constructor stub        init();    }    public WheelView(Context context, AttributeSet attrs) {        super(context, attrs);        // TODO Auto-generated constructor stub        init();    }    public WheelView(Context context) {        super(context);        // TODO Auto-generated constructor stub        init();    }        private void init() {        gestureDetector = new GestureDetector(getContext(), gestureListener);        gestureDetector.setIsLongpressEnabled(false);        scroller = new Scroller(getContext());    }        public WheelAdapter getAdapter() {        return adapter;    }        public void setAdapter(WheelAdapter adapter) {        this.adapter = adapter;        invalidateLayouts();        invalidate();    }        /**     * @param interpolator 动画插补器     */    public void setInterpolator(Interpolator interpolator){        // 立即停止滑动        scroller.forceFinished(true);        scroller = new Scroller(getContext(),interpolator);    }        /**     * 初始布局     */    private void invalidateLayouts() {        itemsLayout = null;        valueLayout = null;        scrollingOffset = 0;    }        public int getVisiableItems() {        return visibleItems;    }        public void setVisiableItems(int count) {        visibleItems = count;        invalidate();    }        public String getLabel() {        return label;    }        public void setLabel(String newLabel) {        if(label == null || !label.equals(newLabel)) {            label = newLabel;            labelLayout = null;            invalidate();         }    }        public void addChangingListener(OnWheelChangedListener listener){        changingListeners.add(listener);    }        public void removeChangingListener(OnWheelChangedListener listener) {        changingListeners.remove(listener);    }    /**     * 更新监听     *      * @param oldValue     * @param newValue     */    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);    }        /**     * 更新滑动监听     */    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;    }        /**     * 设置当前的Item      *      * @param index 下标     * @param animated 是否开启动画效果     */    public void setCurrentItem(int index,boolean animated) {        if(adapter == null || (adapter != null && adapter.getItemCount() == 0)) {            return;        }                if(index < 0 || index >= adapter.getItemCount()) {            if (isCyclic) {                while (index < 0) {                    index += adapter.getItemCount();                }                index %= adapter.getItemCount();            } else{                return;            }        }                 if (index != currentItem) {            if (animated) {                scroll(index - currentItem, SCROLLING_DURATION);            } else {                invalidateLayouts();                            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 isCyclis) {        this.isCyclic = isCyclis;        invalidateLayouts();            invalidate();    }        private void initResourcesIfNecessary() {        if(itemsPaint == null) {            /** 设置粗体  抗锯齿   **/            itemsPaint = new TextPaint(Paint.ANTI_ALIAS_FLAG | Paint.FAKE_BOLD_TEXT_FLAG);            itemsPaint.setTextSize(TEXT_SIZE);        }                if(valuePaint == null) {            /** 设置粗体 抗锯齿  递色   **/            valuePaint = new TextPaint(Paint.ANTI_ALIAS_FLAG                    | Paint.FAKE_BOLD_TEXT_FLAG | Paint.DITHER_FLAG);            valuePaint.setTextSize(TEXT_SIZE);            /** 绘制阴影   **/            valuePaint.setShadowLayer(0.1f, 0, 0.1f, 0xFFC0C0C0);                }                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);    }        /**     * 计算布局的高度     *      * @param layout     * @return     */    private int getDesiredHeight(Layout layout) {        if(layout == null) {            return 0;        }                int desired = getItemHeight() * visibleItems - ITEM_OFFSET * 2                - ADDITIONAL_ITEM_HEIGHT;        // Check against our minimum height        desired = Math.max(desired, getSuggestedMinimumHeight());        return desired;    }        /**     * 设置TextItem     *      * @param index     * @return     */    private String getTextItem(int index) {        if (adapter == null || adapter.getItemCount() == 0) {            return null;        }        int count = adapter.getItemCount();        if ((index < 0 || index >= count) && !isCyclic) {            return null;        } else {            while (index < 0) {                index = count + index;            }        }                index %= count;        return (String) adapter.getItem(index);    }    private String buildText(boolean useCurrentValue) {        StringBuilder itemsText = new StringBuilder();        int addItems = visibleItems / 2 + 1;        for (int i = currentItem - addItems; i <= currentItem + addItems; i++) {            if (useCurrentValue || i != currentItem) {                String text = getTextItem(i);                if (text != null) {                    itemsText.append(text);                }            }            if (i < currentItem + addItems) {                itemsText.append("\n");            }        }                return itemsText.toString();    }        private int getMaxTextLength() {        WheelAdapter adapter = getAdapter();        if (adapter == null) {            return 0;        }                int adapterLength = adapter.getMaxinumLength();        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.getItemCount()); i++) {            String text = (String) adapter.getItem(i);            if (text != null && (maxText == null || maxText.length() < text.length())) {                maxText = text;            }        }        return maxText != null ? maxText.length() : 0;    }        private int getItemHeight() {        if (itemHeight != 0) {            return itemHeight;        } else if (itemsLayout != null && itemsLayout.getLineCount() > 2) {            itemHeight = itemsLayout.getLineTop(2) - itemsLayout.getLineTop(1);            return itemHeight;        }                return getHeight() / visibleItems;    }        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;    }        private void createLayouts(int widthItems, int widthLabel) {        if (itemsLayout == null || itemsLayout.getWidth() > widthItems) {            itemsLayout = new StaticLayout(buildText(isScrollingPerformed), itemsPaint, widthItems,                    widthLabel > 0 ? Layout.Alignment.ALIGN_OPPOSITE : Layout.Alignment.ALIGN_CENTER,                    1, ADDITIONAL_ITEM_HEIGHT, false);        } else {            itemsLayout.increaseWidthTo(widthItems);        }        if (!isScrollingPerformed && (valueLayout == null || valueLayout.getWidth() > widthItems)) {            String text = (String) (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 if (isScrollingPerformed) {            valueLayout = null;        } 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);            }        }        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();        }        drawCenterRect(canvas);        drawShadows(canvas);    }        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);    }    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        if (valueLayout != null) {            canvas.save();            canvas.translate(0, bounds.top + scrollingOffset);            valueLayout.draw(canvas);            canvas.restore();        }    }        private void drawItems(Canvas canvas) {        canvas.save();                int top = itemsLayout.getLineTop(1);        canvas.translate(0, - top + scrollingOffset);                itemsPaint.setColor(ITEMS_TEXT_COLOR);        itemsPaint.drawableState = getDrawableState();        itemsLayout.draw(canvas);                canvas.restore();    }        private void drawCenterRect(Canvas canvas) {        int center = getHeight() / 2;        int offset = getItemHeight() / 2;        centerDrawable.setBounds(0, center - offset, getWidth(), center + offset);        centerDrawable.draw(canvas);    }        /**     * 拦截onTouchEvent     */    @Override    public boolean onTouchEvent(MotionEvent event) {        // TODO Auto-generated method stub        WheelAdapter adapter = getAdapter();        if (adapter == null) {            return true;        }                if (!gestureDetector.onTouchEvent(event)                 && event.getAction() == MotionEvent.ACTION_UP) {            justify();            }        return true;    }    /**     * 滑动     *      * @param delta     */    private void doScroll(int delta) {        scrollingOffset += delta;                int count = scrollingOffset / getItemHeight();        int pos = currentItem - count;        if (isCyclic && adapter.getItemCount() > 0) {            // fix position by rotating            while (pos < 0) {                pos += adapter.getItemCount();            }            pos %= adapter.getItemCount();        } else if (isScrollingPerformed) {            //             if (pos < 0) {                count = currentItem;                pos = 0;            } else if (pos >= adapter.getItemCount()) {                count = currentItem - adapter.getItemCount() + 1;                pos = adapter.getItemCount() - 1;            }        } else {            // fix position            pos = Math.max(pos, 0);            pos = Math.min(pos, adapter.getItemCount() - 1);        }                int offset = scrollingOffset;        if (pos != currentItem) {            setCurrentItem(pos, false);        } else {            invalidate();        }                // update offset        scrollingOffset = offset - count * getItemHeight();        if (scrollingOffset > getHeight()) {            scrollingOffset = scrollingOffset % getHeight() + getHeight();        }    }        /**     * 手势监听事件     */    private SimpleOnGestureListener gestureListener = new SimpleOnGestureListener(){        @Override        public boolean onScroll(MotionEvent e1, MotionEvent e2,                float distanceX, float distanceY) {            // TODO Auto-generated method stub            startScrolling();            doScroll((int)-distanceY);            return true;        }        @Override        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,                float velocityY) {            // TODO Auto-generated method stub            lastScrollY = currentItem * getItemHeight() + scrollingOffset;            int maxY = isCyclic ? 0x7FFFFFFF : adapter.getItemCount() * getItemHeight();            int minY = isCyclic ? -maxY : 0;            scroller.fling(0, lastScrollY, 0, (int) -velocityY / 2, 0, 0, minY, maxY);            setNextMessage(MESSAGE_SCROLL);            return true;        }        @Override        public boolean onDown(MotionEvent e) {            // TODO Auto-generated method stub            if (isScrollingPerformed) {                scroller.forceFinished(true);                clearMessages();                return true;            }            return false;        }    };        private void setNextMessage(int message) {        clearMessages();        animationHandler.sendEmptyMessage(message);    }        /**     * 清空Message     */    private void clearMessages() {        animationHandler.removeMessages(MESSAGE_SCROLL);        animationHandler.removeMessages(MESSAGE_JUSTIFY);    }        /**     * 动画Handler     */    private Handler animationHandler = new Handler() {        public void handleMessage(Message msg) {            scroller.computeScrollOffset();            int currY = scroller.getCurrY();            int delta = lastScrollY - currY;            lastScrollY = currY;            if (delta != 0) {                doScroll(delta);            }                        if (Math.abs(currY - scroller.getFinalY()) < MIN_DELTA_FOR_SCROLLING) {                currY = scroller.getFinalY();                scroller.forceFinished(true);            }            if (!scroller.isFinished()) {                animationHandler.sendEmptyMessage(msg.what);            } else if (msg.what == MESSAGE_SCROLL) {                justify();            } else {                finishScrolling();            }        }    };        private void justify() {        if (adapter == null) {            return;        }                lastScrollY = 0;        int offset = scrollingOffset;        int itemHeight = getItemHeight();        boolean needToIncrease = offset > 0 ? currentItem < adapter.getItemCount() : currentItem > 0;         if ((isCyclic || needToIncrease) && Math.abs((float) offset) > (float) itemHeight / 2) {            if (offset < 0)                offset += itemHeight + MIN_DELTA_FOR_SCROLLING;            else                offset -= itemHeight + MIN_DELTA_FOR_SCROLLING;        }        if (Math.abs(offset) > MIN_DELTA_FOR_SCROLLING) {            scroller.startScroll(0, 0, 0, offset, SCROLLING_DURATION);            setNextMessage(MESSAGE_JUSTIFY);        } else {            finishScrolling();        }    }        /**     * 开始滑动     */    private void startScrolling() {        if (!isScrollingPerformed) {            isScrollingPerformed = true;            notifyScrollingListenersAboutStart();        }    }        /**     * 结束滑动     */    void finishScrolling() {        if (isScrollingPerformed) {            notifyScrollingListenersAboutEnd();            isScrollingPerformed = false;        }        invalidateLayouts();        invalidate();    }        /**     * 滑动这滚轮     *      * @param itemsToScroll     * @param time     */    public void scroll(int itemsToScroll, int time) {        scroller.forceFinished(true);        lastScrollY = scrollingOffset;        int offset = itemsToScroll * getItemHeight();                scroller.startScroll(0, lastScrollY, 0, offset - lastScrollY, time);        setNextMessage(MESSAGE_SCROLL);                startScrolling();    }}
        
       
      
     

WheelAdapter.java:

public interface WheelAdapter {    /** 获取Size **/    public int getItemCount();    /** 获取Item对象  **/    public Object getItem(int index);    /** 获取每个Item的最大长度  用来设置画的时候的宽度  **/    public int getMaxinumLength();}

OnWheelScrollListener.java:

public interface OnWheelScrollListener {        void onScrollingStarted(WheelView wheel);        void onScrollingFinished(WheelView wheel);}

OnWheelChangedListener.java:

public interface OnWheelChangedListener {        void onChanged(WheelView wheel, int oldValue, int newValue);}

适配器NumberWheelAdapter.java:

public class NumberWheelAdapter implements WheelAdapter{    /** The default min value */    public static final int DEFAULT_MAX_VALUE = 9;    /** The default max value */    private static final int DEFAULT_MIN_VALUE = 0;            // Values    private int minValue;    private int maxValue;        // format    private String format;        public NumberWheelAdapter() {        this(DEFAULT_MIN_VALUE, DEFAULT_MAX_VALUE);    }        public NumberWheelAdapter(int minValue, int maxValue) {        this(minValue, maxValue, null);    }    public NumberWheelAdapter(int minValue, int maxValue, String format) {        this.minValue = minValue;        this.maxValue = maxValue;        this.format = format;    }            @Override    public int getItemCount() {        // TODO Auto-generated method stub        return maxValue - minValue + 1;    }    @Override    public Object getItem(int index) {        // TODO Auto-generated method stub        if (index >= 0 && index < getItemCount()) {            int value = minValue + index;            return format != null ? String.format(format, value) : Integer.toString(value);        }        return null;    }    @Override    public int getMaxinumLength() {        // TODO Auto-generated method stub        int max = Math.max(Math.abs(maxValue), Math.abs(minValue));        int maxLen = Integer.toString(max).length();        if (minValue < 0) {            maxLen++;        }        return maxLen;    }    }

activity调用:

mMonthWheel = (WheelView) findViewById(R.id.hour);        mDayWheel = (WheelView) findViewById(R.id.mins);                mMonthWheel.setAdapter(new NumberWheelAdapter(1, 12));        mMonthWheel.setLabel("月");                mDayWheel.setAdapter(new NumberWheelAdapter(1, 31));        mDayWheel.setLabel("日");        mDayWheel.setCyclic(true);