Android仿iPhone的時間輪的工具怎么用

本篇文章給大家分享的是有關Android仿iPhone的時間輪的工具怎么用，小編覺得挺實用的，因此分享給大家學習，希望大家閱讀完這篇文章后可以有所收獲，話不多說，跟著小編一起來看看吧。

相信大家一定都見過iPhone上面的時間滾動輪的效果，類似輪盤一樣的滾動來選擇數據，非常有意思，動畫效果也很生動，相比較安卓自帶的spinner，TimePicker等控件，用戶體驗要好很多。在android上面去實現這樣的效果，需要自定義view來實現，下面一個demo，進行了詳細的注釋，希望對您有所幫助，下面先放上改動之后的效果圖片：

由于代碼比較多，只貼上了自定義view的相關代碼：

package com.cogent.iPhonewheel.widget;  import java.util.LinkedList; import java.util.List;  import android.content.Context; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.Rect; import android.graphics.drawable.Drawable; import android.graphics.drawable.GradientDrawable; import android.graphics.drawable.GradientDrawable.Orientation; import android.os.Handler; import android.os.Message; import android.text.Layout; import android.text.StaticLayout; import android.text.TextPaint; import android.util.AttributeSet; import android.util.FloatMath; import android.view.GestureDetector; import android.view.MotionEvent; import android.view.View; import android.view.GestureDetector.SimpleOnGestureListener; import android.view.animation.Interpolator; import android.widget.Scroller;  import com.cogent.iPhonewheel.Interface.OnWheelChangedListener; import com.cogent.iPhonewheel.Interface.OnWheelScrollListener; import com.cogent.iPhonewheel.Interface.WheelAdapter; import com.cogent.iPhonewheel.UI.R;  /**  * 自定義的滾輪view  *   * @author Administrator  *   */ public class WheelView extends View {     /** 滾動持續的時間 */     private static final int SCROLLING_DURATION = 400;      /** 最少滾動的位置 */     private static final int MIN_DELTA_FOR_SCROLLING = 1;      /** 當前值和標簽的顏色 */     private static final int VALUE_TEXT_COLOR = 0xF0FF6347;      /** item文字的顏色 */     private static final int ITEMS_TEXT_COLOR = 0xFF000000;      /** 頂部和底部陰影的顏色 */     private static final int[] SHADOWS_COLORS = new int[] { 0xFF111111,             0x00AAAAAA, 0x00AAAAAA };      /** 附加的item的高度 */     private static final int ADDITIONAL_ITEM_HEIGHT = 15;      /** 字體大小 */     private static final int TEXT_SIZE = 30;      /** 頂部和底部item的偏移值 */     private static final int ITEM_OFFSET = TEXT_SIZE / 5;      /** item布局的附加寬度 */     private static final int ADDITIONAL_ITEMS_SPACE = 10;      /** 標簽偏移值 */     private static final int LABEL_OFFSET = 8;      /** 左右padding值 */     private static final int PADDING = 10;      /** 默認可見的item數目 */     private static final int DEF_VISIABLE_ITEMS = 5;      /** 初始化wheeladpater */     private WheelAdapter adapter = null;      /** 當前item位置 */     private int currentItem = 0;      /** item寬度 */     private int itemsWidth = 0;      /** 標簽寬度 */     private int labelWidth = 0;      /** 可見item數目 */     private int visibleItems = DEF_VISIABLE_ITEMS;      /** item高度 */     private int itemHeight = 0;      /** item的字符串屬性對象 */     private TextPaint itemsPaint;      /** value的字符串屬性對象 */     private TextPaint valuePaint;      // Layouts     private StaticLayout itemsLayout, labelLayout, valueLayout;      private String label;     private Drawable centerDrawable;      /** 頂部漸變drawable對象 */     private GradientDrawable topShadow;      /** 頂部漸變drawable對象 */     private GradientDrawable bottomShadow;      /** 滾動動作是否執行 */     private boolean isScrollingPerformed;      /** 滾動偏移量 */     private int scrollingOffset;      /** 手勢偵測對象 */     private GestureDetector gestureDetector;      private Scroller scroller;     private int lastScrollY;      /** 是否可循環 */     private boolean isCyclic = false;      /** 實例化OnWheelChangedListener */     private List changingListeners = new LinkedList();      /** 實例化OnWheelScrollListener */     private List scrollingListeners = new LinkedList();      /**      * 3個參數構造函數      */     public WheelView(Context context, AttributeSet attrs, int defStyle) {         super(context, attrs, defStyle);         initData(context);     }      /**      * 2個參數構造函數      */     public WheelView(Context context, AttributeSet attrs) {         super(context, attrs);         initData(context);     }      /**      * 1個參數構造函數      */     public WheelView(Context context) {         super(context);         initData(context);     }      private void initData(Context context) {         gestureDetector = new GestureDetector(context, gestureListener);         gestureDetector.setIsLongpressEnabled(false);// 設置手勢長按不起作用          scroller = new Scroller(context);     }      /**      * 獲取滾輪適配器      *       * @return      */     public WheelAdapter getAdapter() {         return adapter;     }      /**      * 設置滾輪適配器      *       * @param adapter      */     public void setAdapter(WheelAdapter adapter) {         this.adapter = adapter;         invalidateLayouts();         invalidate();// 是視圖無效      }      /**      * 設置指定的滾輪動畫變化率      *       * @param interpolator      */     public void setInterpolator(Interpolator interpolator) {         scroller.forceFinished(true);         scroller = new Scroller(getContext(), interpolator);     }      /**      * 得到可見item的數目      *       * @return the count of visible items      */     public int getVisibleItems() {         return visibleItems;     }      /**      * 設置可見item的數目      *       * @param count      *            the new count      */     public void setVisibleItems(int count) {         visibleItems = count;         invalidate();     }      /**      * 得到標簽      *       * @return      */     public String getLabel() {         return label;     }      /**      * 設置標簽      *       * @param newLabel      */     public void setLabel(String newLabel) {         if (label == null || !label.equals(newLabel)) {             label = newLabel;             labelLayout = null;             invalidate();         }     }      /**      * 增加滾輪變化監聽器      *       * @param listener      */     public void addChangingListener(OnWheelChangedListener listener) {         changingListeners.add(listener);     }      /**      * 移除滾輪變化監聽器      *       * @param listener      */     public void removeChangingListener(OnWheelChangedListener listener) {         changingListeners.remove(listener);     }      /**      * 通知改變的監聽器      *       * @param oldValue      * @param newValue      */     protected void notifyChangingListeners(int oldValue, int newValue) {         for (OnWheelChangedListener listener : changingListeners) {             listener.onChanged(this, oldValue, newValue);         }     }      /**      * 增加滾輪監聽器      *       * @param listener      *            the listener      */     public void addScrollingListener(OnWheelScrollListener listener) {         scrollingListeners.add(listener);     }      /**      * 移除滾輪監聽器      *       * @param listener      *            the listener      */     public void removeScrollingListener(OnWheelScrollListener listener) {         scrollingListeners.remove(listener);     }      /**      * 通知監聽器開始滾動      */     protected void notifyScrollingListenersAboutStart() {         for (OnWheelScrollListener listener : scrollingListeners) {             listener.onScrollingStarted(this);         }     }      /**      * 通知監聽器結束滾動      */     protected void notifyScrollingListenersAboutEnd() {         for (OnWheelScrollListener listener : scrollingListeners) {             listener.onScrollingFinished(this);         }     }      /**      * 取得當前item      *       * @return      */     public int getCurrentItem() {         return currentItem;     }      /**      * 設置當前item      * @param index      * @param animated      */     public void setCurrentItem(int index, boolean animated) {         if (adapter == null || adapter.getItemsCount() == 0) {             return;         }         if (index < 0 || index >= adapter.getItemsCount()) {             if (isCyclic) {                 while (index < 0) {                     index += adapter.getItemsCount();                 }                 index %= adapter.getItemsCount();             } else {                 return;             }         }         if (index != currentItem) {             if (animated) {                 scroll(index - currentItem, SCROLLING_DURATION);             } else {                 invalidateLayouts();                  int old = currentItem;                 currentItem = index;                  notifyChangingListeners(old, currentItem);                 invalidate();             }         }     }      /**      * 設置當前item w/o 動畫. 當index有誤是不做任何響應.      *       * @param index      *            the item index      */     public void setCurrentItem(int index) {         setCurrentItem(index, false);     }      /**      * 測試滾輪是否可循環.      *       * @return true if wheel is cyclic      */     public boolean isCyclic() {         return isCyclic;     }      /**      * 設置滾輪循環標志      *       * @param isCyclic      *            the flag to set      */     public void setCyclic(boolean isCyclic) {         this.isCyclic = isCyclic;          invalidate();         invalidateLayouts();     }      /**      * 使布局無效      */     private void invalidateLayouts() {         itemsLayout = null;         valueLayout = null;         scrollingOffset = 0;     }      /**      * 初始化資源信息      */     private void initResourceIfNecessary() {         if (itemsPaint == null) {             itemsPaint = new TextPaint(Paint.ANTI_ALIAS_FLAG                     | Paint.FAKE_BOLD_TEXT_FLAG);             itemsPaint.setTextSize(TEXT_SIZE);         }          if (valuePaint == null) {             valuePaint = new TextPaint(Paint.ANTI_ALIAS_FLAG                     | Paint.FAKE_BOLD_TEXT_FLAG | Paint.DITHER_FLAG);             valuePaint.setTextSize(TEXT_SIZE);             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);     }           /**      * 計算layout所需的高度      * @param layout      * @return      */     private int getDesiredHeight(Layout layout) {         if (layout == null) {             return 0;         }          int desired = getItemHeight() * visibleItems - ITEM_OFFSET * 2                 - ADDITIONAL_ITEM_HEIGHT;                  desired = Math.max(desired,getSuggestedMinimumHeight());         return desired;     }               /**      * 通過index得到text      * @param index      * @return      */     private String getTextItem(int index){         if(adapter == null || adapter.getItemsCount() == 0){             return null;         }         int count = adapter.getItemsCount();         if((index < 0 || index >= count) && !isCyclic){             return null;         }else{             while(index < 0){                 index += count;             }         }         index %= count;         return adapter.getItem(index);     }          /**      * 根據當前值構建text      *       * @param useCurrentValue      * @return the text      */     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();     }      /**      * 返回可以表示的item的***長度      * @return the max length      */     private int getMaxTextLength() {         WheelAdapter 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;     }      /**      * 返回滾輪item的高度      * @return the item height      */     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;     }      /**      * 計算控制寬度和創建text布局      * @param widthSize the input layout width      * @param mode the layout mode      * @return the calculated control width      */     private int calculateLayoutWidth(int widthSize, int mode) {         initResourceIfNecessary();          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;     }      /**      * 創建布局      * @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(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 = 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);     }      /**      * 在頂部和底部畫陰影的控制      * @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);     }      /**      * 畫value和標簽的布局      * @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         if (valueLayout != null) {             canvas.save();             canvas.translate(0, bounds.top + scrollingOffset);             valueLayout.draw(canvas);             canvas.restore();         }     }      /**      * 畫items      * @param canvas the canvas for drawing      */     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();     }      /**      * 畫當前值的矩形      * @param canvas the canvas for drawing      */     private void drawCenterRect(Canvas canvas) {         int center = getHeight() / 2;         int offset = getItemHeight() / 2;         centerDrawable.setBounds(0, center - offset, getWidth(), center + offset);         centerDrawable.draw(canvas);     }      @Override     public boolean onTouchEvent(MotionEvent event) {         WheelAdapter adapter = getAdapter();         if (adapter == null) {             return true;         }                      if (!gestureDetector.onTouchEvent(event) && event.getAction() == MotionEvent.ACTION_UP) {             justify();         }         return true;     }          /**      * 滾動滾輪      * @param delta the scrolling value      */     private void doScroll(int delta) {         scrollingOffset += delta;                  int count = scrollingOffset / getItemHeight();         int pos = currentItem - count;         if (isCyclic && adapter.getItemsCount() > 0) {             // fix position by rotating             while (pos < 0) {                 pos += adapter.getItemsCount();             }             pos %= adapter.getItemsCount();         } else if (isScrollingPerformed) {             //              if (pos < 0) {                 count = currentItem;                 pos = 0;             } else if (pos >= adapter.getItemsCount()) {                 count = currentItem - adapter.getItemsCount() + 1;                 pos = adapter.getItemsCount() - 1;             }         } else {             // fix position             pos = Math.max(pos, 0);             pos = Math.min(pos, adapter.getItemsCount() - 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();         }     }          // gesture listener     private SimpleOnGestureListener gestureListener = new SimpleOnGestureListener() {         public boolean onDown(MotionEvent e) {             if (isScrollingPerformed) {                 scroller.forceFinished(true);                 clearMessages();                 return true;             }             return false;         }                  public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {             startScrolling();             doScroll((int)-distanceY);             return true;         }                  public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {             lastScrollY = currentItem * getItemHeight() + scrollingOffset;             int maxY = isCyclic ? 0x7FFFFFFF : adapter.getItemsCount() * getItemHeight();             int minY = isCyclic ? -maxY : 0;             scroller.fling(0, lastScrollY, 0, (int) -velocityY / 2, 0, 0, minY, maxY);             setNextMessage(MESSAGE_SCROLL);             return true;         }     };       // Messages     private final int MESSAGE_SCROLL = 0;     private final int MESSAGE_JUSTIFY = 1;          /**      * Set next message to queue. Clears queue before.      *       * @param message the message to set      */     private void setNextMessage(int message) {         clearMessages();         animationHandler.sendEmptyMessage(message);     }      /**      * Clears messages from queue      */     private void clearMessages() {         animationHandler.removeMessages(MESSAGE_SCROLL);         animationHandler.removeMessages(MESSAGE_JUSTIFY);     }          // animation 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);             }                          // scrolling is not finished when it comes to final Y             // so, finish it manually              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();             }         }     };          /**      * Justifies wheel      */     private void justify() {         if (adapter == null) {             return;         }                  lastScrollY = 0;         int offset = scrollingOffset;         int itemHeight = getItemHeight();         boolean needToIncrease = offset > 0 ? currentItem < adapter.getItemsCount() : 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();         }     }          /**      * 開始滾動      */     private void startScrolling() {         if (!isScrollingPerformed) {             isScrollingPerformed = true;             notifyScrollingListenersAboutStart();         }     }      /**      * 停止滾動      */     void finishScrolling() {         if (isScrollingPerformed) {             notifyScrollingListenersAboutEnd();             isScrollingPerformed = false;         }         invalidateLayouts();         invalidate();     }      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();     }  }

以上就是Android仿iPhone的時間輪的工具怎么用，小編相信有部分知識點可能是我們日常工作會見到或用到的。希望你能通過這篇文章學到更多知識。更多詳情敬請關注億速云行業資訊頻道。