Android自定义WheelView

功能

滚轮式选择View,类似于TimePicker、DataPicker,可以设置有无边界（首尾是否相接）

效果图

说明

继承于View，以OverScroller协助完成滚动效果，使用最低API版本为9。如果有需要，可以使用Scroller代替，不影响效果。

尚未添加xml自定义属性，样式设置当前只能使用代码设置。\

部分方法说明

public void addData(String show,Object backData);   //增加数据
public void addData(String data);                   //增加数据
public void setCircle(boolean isCircle);            //设置是否首尾相接
public void setRate(int rate);                      //设置滑动速度变化率
public void notifyDataSetChanged();                 //刷新数据及设置
public void setCenterItem(int position);            //设置被选中的位置(必须在数据添加后调用)
public void setCenterItem(String showData);         //设置被选中的数据(必须在数据添加后调用)
public Object getCenterItem();                      //获取当前被选中的数据
public void setLineColor(int lineColor);            //设置中间线条的颜色
public void setTextColor(int textColor);            //设置文字的颜色
public void setTextSize(float textSize);            //设置文字大小```

使用示例

View wh= LayoutInflater.from(this).inflate(R.layout.common_window_wheel,null);

final WheelView picker= (WheelView) wh.findViewById(R.id.wheel);

picker.addData(“详情”);

picker.addData(“概要”);

picker.addData(“病历”);

picker.addData(“医嘱”);

picker.addData(“检验”);

picker.addData(“检查”);

picker.addData(“体征”);

picker.setCenterItem(4);

WPopupWindow popupWindow=new WPopupWindow(wh);

popupWindow.showAtLocation(getContentView(), Gravity.BOTTOM, 0, 0);

wh.findViewById(R.id.right).setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

LogUtils.e(“nowData->”+picker.getCenterItem());

}

});

**xml代码**

**源码**

package com.newbjgoodwill.mobilecwr.view;

import android.content.Context;

import android.graphics.Canvas;

import android.graphics.LinearGradient;

import android.graphics.Paint;

import android.graphics.Shader;

import android.util.AttributeSet;

import android.view.MotionEvent;

import android.view.View;

import android.widget.OverScroller;

import java.util.ArrayList;

/**

* Created by zhangjianmin on 2017/12/1.

*/

public class WheelView extends View{

private float scrollY=0;

private int scrollX=0;

private int showSize=5;             //展示Item的个数
private float textSize=16;          //文字的大小
private boolean isCircle=false;     //是否为环形
private int rate=120;               //惯性滑动比率，rate越大，速率越快
private int textColor=0xFF000000;   //文字颜色
private int lineColor=0xFF888888;   //线条的颜色

private int cacheNowItem=-1;        //预设当前item的位置，负数表示不设定

private int currentItem=-1;         //当前item位置

private int width;                  //view的宽度
private int height;                 //view的高度
private int itemHeight;             //item的高度
private int itemX;                  //item的X位置
private float centerItemTop;        //中心Item的上边距位置
private float centerItemBottom;     //中心Item的下边距位置
private float centerItemHeight;     //中心Item的高度

private int realHeight;             //内容的实际高度
private int minScrollY;             //最小滚动高度
private int maxScrollY;             //最大滚动高度

private ArrayList<HashBean> data;   //数据集合
private int dataSize=0;
private Paint paint;
private Paint coverPaint;           //遮罩paint
private Shader shader;              //遮罩渐变

private float lastY,downY;          //上次操作的坐标以及按下时候的坐标
private long downTime;              //按下时的时间

private OverScroller mScroller;

public boolean isStart=true;

public WheelView(Context context) {
this(context, null);
}

public WheelView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}

public WheelView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}

private void init(){
mScroller=new OverScroller(getContext());
data=new ArrayList<>();
paint=new Paint();
paint.setAntiAlias(true);
paint.setTextSize(DensityUtils.dp2px(getContext(),textSize));
paint.setTextAlign(Paint.Align.CENTER);
coverPaint=new Paint();
if(showSize%2==0){
showSize+=1;
}
}

/**
* 增加数据
* @param show  显示数据
* @param backData  选中时的返回数据
*/
public void addData(String show,Object backData){
data.add(new HashBean(show, backData));
dataSize++;
}

/**
* 增加数据
* @param data 显示数据和选中时的返回数据
*/
public void addDatas(String data,Object showPage){
addData(data, showPage);
}

public void clearData(){
data.clear();
}

public void setCircle(boolean isCircle){
this.isCircle=isCircle;
}

public void setTextColor(int textColor){
this.textColor=textColor;
invalidate();
}

public void setLineColor(int lineColor){
this.lineColor=lineColor;
invalidate();
}

public void setTextSize(float textSize){
this.textSize=textSize;
paint.setTextSize(DensityUtils.dp2px(getContext(),textSize));
invalidate();
}

public void setRate(int rate){
this.rate=rate;
}

public void notifyDataSetChanged(){
isStart=true;
invalidate();
}

private void measureData(){
if(isStart){
width=getWidth();
itemX=width/2;
height=getHeight();
itemHeight=(height-getPaddingTop()-getPaddingBottom())/showSize;
realHeight=dataSize*itemHeight;
minScrollY=-(getRealHeight()-(showSize+1)/2*itemHeight);
maxScrollY=(showSize-1)/2*itemHeight;
centerItemHeight=itemHeight;
centerItemTop=(height-getPaddingTop()-getPaddingBottom())/2+getPaddingTop()-centerItemHeight/2;
centerItemBottom=(height-getPaddingTop()-getPaddingBottom())/2+getPaddingTop()+centerItemHeight/2;
shader=new LinearGradient(0,0,0,height,new int[]{
0xFFFFFFFF,0xAAFFFFFF,0x00FFFFFF,0x00FFFFFF,0xAAFFFFFF,0xFFFFFFFF
},new float[]{
0.0f,centerItemTop/height,centerItemTop/height,centerItemBottom/height,centerItemBottom/height,1.0f
}, Shader.TileMode.REPEAT);
coverPaint.setShader(shader);
isStart=false;
}
}

@Override
public void computeScroll() {
//scroller的滚动是否完成
if(mScroller.computeScrollOffset()){
scrollY=mScroller.getCurrY();
invalidate();
}
super.computeScroll();
}

@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
measureData();
//如果设置了当前选中
if(cacheNowItem>=0){
scrollY=-(cacheNowItem-(showSize-1)/2)*itemHeight;
cacheNowItem=-1;
}
int startItemPos=(int)-scrollY/itemHeight;      //绘制的数据的起始位置
paint.setColor(textColor);
for(int i=startItemPos,j=0;i<startItemPos+showSize+2;j++,i++){
float topY=j*itemHeight+scrollY%itemHeight;
if(i>=0&&i<dataSize){
canvas.drawText(data.get(i).showStr,itemX,
getBaseLine(paint,topY,itemHeight),paint);
}else{
if(isCircle){
int pos=i%dataSize;
canvas.drawText(data.get(pos<0?pos+dataSize:pos).showStr,itemX,
getBaseLine(paint,topY,itemHeight),paint);
}
}
}

//绘制中间的线条和遮罩层
paint.setColor(lineColor);
canvas.drawLine(getPaddingLeft(), centerItemTop, width-getPaddingRight(),centerItemTop,paint);
canvas.drawLine(getPaddingLeft(), centerItemBottom, width-getPaddingRight(), centerItemBottom, paint);
coverPaint.setShader(shader);
canvas.drawRect(0, 0, width, height, coverPaint);
}

/**
* 获取数据集合的大小
* @param isRefresh 是否重新计算数据集合大小
* @return
*/
public int getDataSize(boolean isRefresh){
if(isRefresh){
dataSize=data.size();
}
return data.size();
}

/**
* 设置当前Item的位置
* @param position
*/
public void setCenterItem(int position){
if(position>=0&&position<dataSize){
cacheNowItem=position;
}
invalidate();
}

/**
* 设置选中内容
* @param showData
*/
public void setCenterItem(String showData){
int size=data.size();
for(int i=0;i<size;i++){
if(showData.equals(data.get(i).showStr)){
cacheNowItem=i;
invalidate();
return;
}
}
}

/**
* 获取选中内容的数据
*
* @return
*/
public Object getCenterItem(){
if(cacheNowItem>=0){
return data.get(cacheNowItem).backData;
}else{
int dy=(int)scrollY%itemHeight;         //不足一个Item高度的部分
if(Math.abs(dy)>itemHeight/2){          //如果偏移大于item的一半，
if(scrollY<0){
scrollY= scrollY-itemHeight-dy;
}else{
scrollY=scrollY+itemHeight-dy;
}
}else{
scrollY=scrollY-dy;
}
mScroller.forceFinished(true);
invalidate();
int nowChecked;
if(!isCircle){
if(scrollY<minScrollY){
nowChecked=dataSize-1;
}else if(scrollY>maxScrollY){
nowChecked=0;
}else{
nowChecked= (int) (-scrollY/itemHeight+(showSize-1)/2);
}
}else{
//滚轮时，重置scrollY位置，使它出现在限定范围的等效位置
//以minScroll为相对0点，进行调整
if(scrollY<minScrollY||scrollY>=maxScrollY){
int mid= (int) ((scrollY-minScrollY)%realHeight);
if(mid<0){
mid+=realHeight;
}
scrollY=mid+minScrollY;
}
nowChecked= (int) (-scrollY/itemHeight+(showSize-1)/2);
}
return dataSize>0?data.get(nowChecked).backData:null;
}
}
/**
* 获取选中的内容
*
* @return
*/
public Object getCenterData(){
if(cacheNowItem>=0){
return data.get(cacheNowItem).showStr;
}else{
int dy=(int)scrollY%itemHeight;         //不足一个Item高度的部分
if(Math.abs(dy)>itemHeight/2){          //如果偏移大于item的一半，
if(scrollY<0){
scrollY= scrollY-itemHeight-dy;
}else{
scrollY=scrollY+itemHeight-dy;
}
}else{
scrollY=scrollY-dy;
}
mScroller.forceFinished(true);
invalidate();
int nowChecked;
if(!isCircle){
if(scrollY<minScrollY){
nowChecked=dataSize-1;
}else if(scrollY>maxScrollY){
nowChecked=0;
}else{
nowChecked= (int) (-scrollY/itemHeight+(showSize-1)/2);
}
}else{
//滚轮时，重置scrollY位置，使它出现在限定范围的等效位置
//以minScroll为相对0点，进行调整
if(scrollY<minScrollY||scrollY>=maxScrollY){
int mid= (int) ((scrollY-minScrollY)%realHeight);
if(mid<0){
mid+=realHeight;
}
scrollY=mid+minScrollY;
}
nowChecked= (int) (-scrollY/itemHeight+(showSize-1)/2);
}
return dataSize>0?data.get(nowChecked).showStr:null;
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()){
case MotionEvent.ACTION_DOWN:
downTime=System.currentTimeMillis();
downY=event.getRawY();
lastY=downY;
break;
case MotionEvent.ACTION_MOVE:
float y=event.getRawY();
float dy=y-lastY;
pretendScrollY(dy);
lastY=y;
break;
case MotionEvent.ACTION_UP:
checkStateAndPosition();
invalidate();
break;
}
return true;
}

private int getRealHeight(){
if(realHeight==0){
realHeight=dataSize*itemHeight;
}
return realHeight;
}

private void checkStateAndPosition(){
//上拉超出
if(!isCircle&&scrollY<-(getRealHeight()-(showSize+1)/2*itemHeight)){
mScroller.startScroll(0, (int)scrollY, 0, (showSize+1)/2*itemHeight-getRealHeight() - (int)scrollY,400);

// mScroller.springBack(0,(int)scrollY,0,0,minScrollY,maxScrollY);

}else if(!isCircle&&scrollY>(showSize-1)/2*itemHeight){ //下拉超出

mScroller.startScroll(0, (int) scrollY, 0, (showSize - 1) / 2 * itemHeight - (int) scrollY, 400);

// mScroller.springBack(0,(int)scrollY,0,0,minScrollY,maxScrollY);

}else{

long endTime=System.currentTimeMillis();

//超出滑动时间或者不足滑动距离

if(endTime-downTime>250||Math.abs(lastY-downY)

**WPopupWindow的源码**

package com.newbjgoodwill.mobilecwr.view;

import android.annotation.TargetApi;

import android.app.Activity;

import android.content.Context;

import android.graphics.drawable.BitmapDrawable;

import android.os.Build;

import android.util.AttributeSet;

import android.view.Gravity;

import android.view.MotionEvent;

import android.view.View;

import android.view.ViewGroup;

import android.view.WindowManager;

import android.widget.PopupWindow;

/**

* Created by zhangjianmin on 2017/12/1.

*/

public class WPopupWindow extends PopupWindow {

private Context context;

private boolean isBgAlpha=true;

private float alpha=0.5f;

public WPopupWindow(View contentView) {
this(contentView, ViewGroup.LayoutParams.MATCH_PARENT , ViewGroup.LayoutParams.WRAP_CONTENT);
}

public WPopupWindow(Context context) {
this(context,null);
}

public WPopupWindow(int width, int height) {
this(null,width, height);
}

public WPopupWindow(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public WPopupWindow(View contentView, int width, int height) {
this(contentView, width, height, false);
}
public WPopupWindow(Context context, AttributeSet attrs, int defStyleAttr) {
this(context, attrs, defStyleAttr, 0);
}

@TargetApi(Build.VERSION_CODES.HONEYCOMB)
public WPopupWindow(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
this.context=context;
init();
}

public WPopupWindow(View contentView, int width, int height, boolean focusable) {
super(contentView, width, height, focusable);
this.context=contentView.getContext();
init();
}

public void setBgAlpha(boolean isAlpha,float alpha){
this.isBgAlpha=isAlpha;
this.alpha=alpha;
}

@Override
public void showAsDropDown(View anchor) {
this.showAsDropDown(anchor,0,0);
}

@Override
public void showAsDropDown(View anchor, int xoff, int yoff) {
this.showAsDropDown(anchor, xoff, yoff, Gravity.TOP | Gravity.START);
}

@Override
public void showAsDropDown(View anchor, int xoff, int yoff, int gravity) {
setWindowFilter(isBgAlpha, alpha);
super.showAsDropDown(anchor, xoff, yoff, gravity);
}

@Override
public void showAtLocation(View parent, int gravity, int x, int y) {
setWindowFilter(isBgAlpha, alpha);
super.showAtLocation(parent, gravity, x, y);
}

public void init(){
setOnDismissListener(new OnDismissListener() {
@Override
public void onDismiss() {
setWindowFilter(isBgAlpha, 1f);
}
});
setFocusable(true);
setTouchable(true);
setOutsideTouchable(true);
setOutTouchCancel(false);
}

/**
* @param isCancel  点击对话框外时，是否取消对话框
*/
public void setOutTouchCancel(boolean isCancel){
if(isCancel){
setBackgroundDrawable(new BitmapDrawable());
setTouchInterceptor(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
if (MotionEvent.ACTION_OUTSIDE == event.getAction()) {
dismiss();
return true;
}
return false;
}
});
}else{
setBackgroundDrawable(null);
setTouchInterceptor(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
return false;
}
});
}
}

public void setWindowFilter(boolean isBgAlpha,float alpha) {
if (isBgAlpha) {
WindowManager.LayoutParams lp = ((Activity) context).getWindow().getAttributes();
lp.alpha = alpha;
//保证华为honor颜色变暗
lp.dimAmount=alpha;
((Activity) context).getWindow().setFlags(WindowManager.LayoutParams.FLAG_BLUR_BEHIND,
WindowManager.LayoutParams.FLAG_BLUR_BEHIND);
((Activity) context).getWindow().addFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND);
////////////////////////////////////////////////////
((Activity) context).getWindow().setAttributes(lp);
}
}

}

**DensityUtils 源码**

package com.newbjgoodwill.mobilecwr.view;

import android.content.Context;

import android.util.TypedValue;

/**

* Created by zhangjianmin on 2017/12/1.

*/

public class DensityUtils {

private DensityUtils() {

/* cannot be instantiated */

throw new UnsupportedOperationException(“cannot be instantiated”);

}

/**
* dp转px
*
* @param context
* @param val
* @return
*/
public static float dp2px(Context context, float dpVal) {
return (float) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
dpVal, context.getResources().getDisplayMetrics());
}

/**
* sp转px
*
* @param context
* @param val
* @return
*/
public static int sp2px(Context context, float spVal) {
return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP,
spVal, context.getResources().getDisplayMetrics());
}

/**
* px转dp
*
* @param context
* @param pxVal
* @return
*/
public static float px2dp(Context context, float pxVal) {
final float scale = context.getResources().getDisplayMetrics().density;
return (pxVal / scale);
}

/**
* px转sp
*
* @param fontScale
* @param pxVal
* @return
*/
public static float px2sp(Context context, float pxVal) {
return (pxVal / context.getResources().getDisplayMetrics().scaledDensity);
}

}

“`