本文主要是介绍Android时间轴控件-WheelView,希望对大家解决编程问题提供一定的参考价值,需要的开发者们随着小编来一起学习吧!
在做时间轴或者某些类型的选择时,有时候设计师会给我们出类似下面的效果:
因此,我们就需要重新自定义scrollview,,也就是移动端常用的时间轴控件:WheelView
实现方式直接上代码:
public class WheelView extends ScrollView {public static final String TAG = WheelView.class.getSimpleName();public static class OnWheelViewListener {public void onSelected(int selectedIndex, String item) {}}private Context context;
// private ScrollView scrollView;private LinearLayout views;public WheelView(Context context) {super(context);init(context);}public WheelView(Context context, AttributeSet attrs) {super(context, attrs);init(context);}public WheelView(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);init(context);}// String[] items;List<String> items;private List<String> getItems() {return items;}public void setItems(List<String> list) {if (null == items) {items = new ArrayList<String>();}items.clear();items.addAll(list);// 前面和后面补全for (int i = 0; i < offset; i++) {items.add(0, "");items.add("");}initData();}// 每页显示的数量public static final int OFF_SET_DEFAULT = 1;int offset = OFF_SET_DEFAULT; // 偏移量(需要在最前面和最后面补全)int displayItemCount;int selectedIndex = 1; //int itemHeight = 0;//每个条目的高度int textSize = 20;//每个条目的字体大小public int getOffset() {return offset;}public void setOffset(int offset) {this.offset = offset;}public void setTextSize(int textSize) {this.textSize = textSize;}private void init(Context context) {this.context = context;// scrollView = ((ScrollView)this.getParent());
// Log.d(TAG, "scrollview: " + scrollView);Log.d(TAG, "parent: " + this.getParent());
// this.setOrientation(VERTICAL);this.setVerticalScrollBarEnabled(false);views = new LinearLayout(context);views.setOrientation(LinearLayout.VERTICAL);this.addView(views);scrollerTask = new Runnable() {public void run() {int newY = getScrollY();if (initialY - newY == 0) { // stoppedfinal int remainder = initialY % itemHeight;final int divided = initialY / itemHeight;
// Log.d(TAG, "initialY: " + initialY);
// Log.d(TAG, "remainder: " + remainder + ", divided: " + divided);if (remainder == 0) {selectedIndex = divided + offset;onSeletedCallBack();} else {if (remainder > itemHeight / 2) {WheelView.this.post(new Runnable() {@Overridepublic void run() {WheelView.this.smoothScrollTo(0, initialY - remainder + itemHeight);selectedIndex = divided + offset + 1;onSeletedCallBack();}});} else {WheelView.this.post(new Runnable() {@Overridepublic void run() {WheelView.this.smoothScrollTo(0, initialY - remainder);selectedIndex = divided + offset;onSeletedCallBack();}});}}} else {initialY = getScrollY();WheelView.this.postDelayed(scrollerTask, newCheck);}}};}int initialY;Runnable scrollerTask;int newCheck = 50;public void startScrollerTask() {initialY = getScrollY();this.postDelayed(scrollerTask, newCheck);}private void initData() {displayItemCount = offset * 2 + 1;for (String item : items) {views.addView(createView(item));}refreshItemView(0);}private TextView createView(String item) {TextView tv = new TextView(context);tv.setLayoutParams(new LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT));tv.setSingleLine(true);tv.setTextSize(TypedValue.COMPLEX_UNIT_SP, textSize);tv.setText(item);tv.setGravity(Gravity.CENTER);int padding = dip2px(15);tv.setPadding(padding, padding, padding, padding);if (0 == itemHeight) {itemHeight = getViewMeasuredHeight(tv);Log.d(TAG, "itemHeight: " + itemHeight);views.setLayoutParams(new LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, itemHeight * displayItemCount));LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) this.getLayoutParams();this.setLayoutParams(new LinearLayout.LayoutParams(lp.width, itemHeight * displayItemCount));}return tv;}@Overrideprotected void onScrollChanged(int l, int t, int oldl, int oldt) {super.onScrollChanged(l, t, oldl, oldt);// Log.d(TAG, "l: " + l + ", t: " + t + ", oldl: " + oldl + ", oldt: " + oldt);// try {
// Field field = ScrollView.class.getDeclaredField("mScroller");
// field.setAccessible(true);
// OverScroller mScroller = (OverScroller) field.get(this);
//
//
// if(mScroller.isFinished()){
// Log.d(TAG, "isFinished...");
// }
//
// } catch (Exception e) {
// e.printStackTrace();
// }refreshItemView(t);if (t > oldt) {
// Log.d(TAG, "向下滚动");scrollDirection = SCROLL_DIRECTION_DOWN;} else {
// Log.d(TAG, "向上滚动");scrollDirection = SCROLL_DIRECTION_UP;}}private void refreshItemView(int y) {int position = y / itemHeight + offset;int remainder = y % itemHeight;int divided = y / itemHeight;if (remainder == 0) {position = divided + offset;} else {if (remainder > itemHeight / 2) {position = divided + offset + 1;}// if(remainder > itemHeight / 2){
// if(scrollDirection == SCROLL_DIRECTION_DOWN){
// position = divided + offset;
// Log.d(TAG, ">down...position: " + position);
// }else if(scrollDirection == SCROLL_DIRECTION_UP){
// position = divided + offset + 1;
// Log.d(TAG, ">up...position: " + position);
// }
// }else{position = y / itemHeight + offset;
// if(scrollDirection == SCROLL_DIRECTION_DOWN){
// position = divided + offset;
// Log.d(TAG, "<down...position: " + position);
// }else if(scrollDirection == SCROLL_DIRECTION_UP){
// position = divided + offset + 1;
// Log.d(TAG, "<up...position: " + position);
// }
// }
// }// if(scrollDirection == SCROLL_DIRECTION_DOWN){
// position = divided + offset;
// }else if(scrollDirection == SCROLL_DIRECTION_UP){
// position = divided + offset + 1;}int childSize = views.getChildCount();for (int i = 0; i < childSize; i++) {TextView itemView = (TextView) views.getChildAt(i);if (null == itemView) {return;}if (position == i) {itemView.setTextColor(checkTextColor);} else {itemView.setTextColor(nocheckTextColor);}}}int checkTextColor = Color.parseColor("#0288ce");int nocheckTextColor = Color.parseColor("#bbbbbb");//设置选中的字体颜色public void setCheckTextColor(String checkTextColor) {this.checkTextColor = Color.parseColor(checkTextColor);}public void setCheckTextColor(int checkTextColor) {this.checkTextColor = checkTextColor;}//设置未选中的字体颜色public void setNocheckTextColor(String nocheckTextColor) {this.nocheckTextColor = Color.parseColor(nocheckTextColor);}public void setNocheckTextColor(int nocheckTextColor) {this.nocheckTextColor = nocheckTextColor;}/*** 获取选中区域的边界*/int[] selectedAreaBorder;private int[] obtainSelectedAreaBorder() {if (null == selectedAreaBorder) {selectedAreaBorder = new int[2];selectedAreaBorder[0] = itemHeight * offset;selectedAreaBorder[1] = itemHeight * (offset + 1);}return selectedAreaBorder;}private int scrollDirection = -1;private static final int SCROLL_DIRECTION_UP = 0;private static final int SCROLL_DIRECTION_DOWN = 1;Paint paint;int viewWidth;@Overridepublic void setBackgroundDrawable(Drawable background) {if (viewWidth == 0) {viewWidth = ((Activity) context).getWindowManager().getDefaultDisplay().getWidth();Log.d(TAG, "viewWidth: " + viewWidth);}if (null == paint) {paint = new Paint();paint.setColor(Color.parseColor("#83cde6"));paint.setStrokeWidth(dip2px(1f));}background = new Drawable() {@Overridepublic void draw(Canvas canvas) {canvas.drawLine(viewWidth * 1 / 6, obtainSelectedAreaBorder()[0], viewWidth * 5 / 6, obtainSelectedAreaBorder()[0], paint);canvas.drawLine(viewWidth * 1 / 6, obtainSelectedAreaBorder()[1], viewWidth * 5 / 6, obtainSelectedAreaBorder()[1], paint);}@Overridepublic void setAlpha(int alpha) {}@Overridepublic void setColorFilter(ColorFilter cf) {}@SuppressLint("WrongConstant")@Overridepublic int getOpacity() {return 0;}};super.setBackgroundDrawable(background);}@Overrideprotected void onSizeChanged(int w, int h, int oldw, int oldh) {super.onSizeChanged(w, h, oldw, oldh);Log.d(TAG, "w: " + w + ", h: " + h + ", oldw: " + oldw + ", oldh: " + oldh);viewWidth = w;setBackgroundDrawable(null);}/*** 选中回调*/private void onSeletedCallBack() {if (null != onWheelViewListener) {onWheelViewListener.onSelected(selectedIndex, items.get(selectedIndex));}}public void setSeletion(int position) {final int p = position;selectedIndex = p + offset;this.post(new Runnable() {@Overridepublic void run() {WheelView.this.smoothScrollTo(0, p * itemHeight);}});}public String getSeletedItem() {return items.get(selectedIndex);}public int getSeletedIndex() {return selectedIndex - offset;}@Overridepublic void fling(int velocityY) {super.fling(velocityY / 3);}@Overridepublic boolean onTouchEvent(MotionEvent ev) {if (ev.getAction() == MotionEvent.ACTION_UP) {startScrollerTask();}return super.onTouchEvent(ev);}private OnWheelViewListener onWheelViewListener;public OnWheelViewListener getOnWheelViewListener() {return onWheelViewListener;}public void setOnWheelViewListener(OnWheelViewListener onWheelViewListener) {this.onWheelViewListener = onWheelViewListener;}private int dip2px(float dpValue) {final float scale = context.getResources().getDisplayMetrics().density;return (int) (dpValue * scale + 0.5f);}private int getViewMeasuredHeight(View view) {int width = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);int expandSpec = View.MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2, View.MeasureSpec.AT_MOST);view.measure(width, expandSpec);return view.getMeasuredHeight();}}
外面设置属性和传数据的使用方式如下:
val layout_wheelview = findViewById<WheelView>(R.id.layout_wheelview).apply {//设置选中的字体颜色setCheckTextColor(Color.BLACK)//设置条目字体大小setTextSize(18)//设置列表数据setItems(listContent)//添加滑动监听onWheelViewListener = object : WheelView.OnWheelViewListener() {override fun onSelected(selectedIndex: Int, item: String) {}}}
外面获取当前选中的条目:
layout_wheelview.seletedIndex
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