自定义
//创建一个类
@SuppressLint({"HandlerLeak","ClickableViewAccessibility" })
public class PickerScrollView extends View {
public static final StringTAG ="PickerView";
/**
* text之间间距和minTextSize之比
*/
public static final float MARGIN_ALPHA =2.8f;
/**
* 自动回滚到中间的速度
*/
public static final float SPEED =2;
private ListmDataList;
/**
* 选中的位置，这个位置是mDataList的中心位置，一直不变
*/
private int mCurrentSelected;
private PaintmPaint;
private float mMaxTextSize =20;
private float mMinTextSize =10;
private float mMaxTextAlpha =255;
private float mMinTextAlpha =120;
private int mColorText =0x333333;
private int mViewHeight;
private int mViewWidth;
private float mLastDownY;
/**
* 滑动的距离
*/
private float mMoveLen =0;
private boolean isInit =false;
private onSelectListenermSelectListener;
private Timertimer;
private MyTimerTaskmTask;
HandlerupdateHandler =new Handler() {
@Override
public void handleMessage(Message msg) {
if (Math.abs(mMoveLen)
mMoveLen =0;
if (mTask !=null) {
mTask.cancel();
mTask =null;
performSelect();
}
}else
// 这里mMoveLen / Math.abs(mMoveLen)是为了保有mMoveLen的正负号，以实现上滚或下滚
mMoveLen =mMoveLen -mMoveLen / Math.abs(mMoveLen) *SPEED;
invalidate();
}
};
public PickerScrollView(Context context) {
super(context);
init();
}
public PickerScrollView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public void setOnSelectListener(onSelectListener listener) {
mSelectListener = listener;
}
private void performSelect() {
if (mSelectListener !=null)
mSelectListener.onSelect(mDataList.get(mCurrentSelected));
}
public void setData(List datas) {
mDataList = datas;
mCurrentSelected = datas.size() /2;
invalidate();
}
/**
* 选择选中的item的index
*
* @param selected
*/
public void setSelected(int selected) {
mCurrentSelected = selected;
int distance =mDataList.size() /2 -mCurrentSelected;
if (distance <0)
for (int i =0; i < -distance; i++) {
moveHeadToTail();
mCurrentSelected--;
}
else if (distance >0)
for (int i =0; i < distance; i++) {
moveTailToHead();
mCurrentSelected++;
}
invalidate();
}
/**
* 选择选中的内容
*
* @param mSelectItem
*/
public void setSelected(String mSelectItem) {
for (int i =0; i
if (mDataList.get(i).equals(mSelectItem)) {
setSelected(i);
break;
}
}
private void moveHeadToTail() {
Pickers head =mDataList.get(0);
mDataList.remove(0);
mDataList.add(head);
}
private void moveTailToHead() {
Pickers tail =mDataList.get(mDataList.size() -1);
mDataList.remove(mDataList.size() -1);
mDataList.add(0, tail);
}
@Override
protected void onMeasure(int widthMeasureSpec,int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
mViewHeight = getMeasuredHeight();
mViewWidth = getMeasuredWidth();
// 按照View的高度计算字体大小
mMaxTextSize =mViewHeight /8.0f;
mMinTextSize =mMaxTextSize /2f;
isInit =true;
invalidate();
}
private void init() {
timer =new Timer();
mDataList =new ArrayList();
mPaint =new Paint(Paint.ANTI_ALIAS_FLAG);
mPaint.setStyle(Paint.Style.FILL);
mPaint.setTextAlign(Paint.Align.CENTER);
mPaint.setColor(mColorText);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
// 根据index绘制view
if (isInit)
drawData(canvas);
}
private void drawData(Canvas canvas) {
// 先绘制选中的text再往上往下绘制其余的text
float scale = parabola(mViewHeight /4.0f,mMoveLen);
float size = (mMaxTextSize -mMinTextSize) * scale +mMinTextSize;
mPaint.setTextSize(size);
mPaint.setAlpha((int) ((mMaxTextAlpha -mMinTextAlpha) * scale +mMinTextAlpha));
// text居中绘制，注意baseline的计算才能达到居中，y值是text中心坐标
float x = (float) (mViewWidth /2.0);
float y = (float) (mViewHeight /2.0 +mMoveLen);
Paint.FontMetricsInt fmi =mPaint.getFontMetricsInt();
float baseline = (float) (y - (fmi.bottom /2.0 + fmi.top /2.0));
int indexs =mCurrentSelected;
String textData =mDataList.get(indexs).getShowConetnt();
canvas.drawText(textData, x, baseline,mPaint);
// 绘制上方data
for (int i =1; (mCurrentSelected - i) >=0; i++) {
drawOtherText(canvas, i, -1);
}
// 绘制下方data
for (int i =1; (mCurrentSelected + i)
drawOtherText(canvas, i,1);
}
}
/**
* @param canvas
* @param position
* 距离mCurrentSelected的差值
* @param type
* 1表示向下绘制，-1表示向上绘制
*/
private void drawOtherText(Canvas canvas,int position,int type) {
float d = (float) (MARGIN_ALPHA *mMinTextSize * position + type
*mMoveLen);
float scale = parabola(mViewHeight /4.0f, d);
float size = (mMaxTextSize -mMinTextSize) * scale +mMinTextSize;
mPaint.setTextSize(size);
mPaint.setAlpha((int) ((mMaxTextAlpha -mMinTextAlpha) * scale +mMinTextAlpha));
float y = (float) (mViewHeight /2.0 + type * d);
Paint.FontMetricsInt fmi =mPaint.getFontMetricsInt();
float baseline = (float) (y - (fmi.bottom /2.0 + fmi.top /2.0));
int indexs =mCurrentSelected + type * position;
String textData =mDataList.get(indexs).getShowConetnt();
canvas.drawText(textData, (float) (mViewWidth /2.0), baseline,mPaint);
}
/**
* 抛物线
*
* @param zero
* 零点坐标
* @param x
* 偏移量
* @return scale
*/
private float parabola(float zero,float x) {
float f = (float) (1 - Math.pow(x / zero,2));
return f <0 ?0 : f;
}
@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getActionMasked()) {
case MotionEvent.ACTION_DOWN:
doDown(event);
break;
case MotionEvent.ACTION_MOVE:
doMove(event);
break;
case MotionEvent.ACTION_UP:
doUp(event);
break;
}
return true;
}
private void doDown(MotionEvent event) {
if (mTask !=null) {
mTask.cancel();
mTask =null;
}
mLastDownY = event.getY();
}
private void doMove(MotionEvent event) {
mMoveLen += (event.getY() -mLastDownY);
if (mMoveLen >MARGIN_ALPHA *mMinTextSize /2) {
// 往下滑超过离开距离
moveTailToHead();
mMoveLen =mMoveLen -MARGIN_ALPHA *mMinTextSize;
}else if (mMoveLen < -MARGIN_ALPHA *mMinTextSize /2) {
// 往上滑超过离开距离
moveHeadToTail();
mMoveLen =mMoveLen +MARGIN_ALPHA *mMinTextSize;
}
mLastDownY = event.getY();
invalidate();
}
private void doUp(MotionEvent event) {
// 抬起手后mCurrentSelected的位置由当前位置move到中间选中位置
if (Math.abs(mMoveLen) <0.0001) {
mMoveLen =0;
return;
}
if (mTask !=null) {
mTask.cancel();
mTask =null;
}
mTask =new MyTimerTask(updateHandler);
timer.schedule(mTask,0,10);
}
class MyTimerTaskextends TimerTask {
Handlerhandler;
public MyTimerTask(Handler handler) {
this.handler = handler;
}
@Override
public void run() {
handler.sendMessage(handler.obtainMessage());
}
}
public interface onSelectListener {
void onSelect(Pickers pickers);
}
}
//xml布局控件使用
android:layout_marginTop="20dp"
android:id="@+id/pic"
android:layout_width="match_parent"
android:layout_height="200dp" />
private Listlist;// 滚动选择器数据
private String[]id;
private String[]name;
//初始化数据
private void initData() {
list =new ArrayList();
id =new String[]{"1","2","3","4","5","6","7","8","9"};
name =new String[]{"北京市","安阳市","丽江市","天津市","长春市","昆明市","哈尔滨市","葫芦岛","Your Heart"};
for (int i =0; i
list.add(new Pickers(name[i],id[i]));
}
// 设置数据，默认选择第一条
pic.setData(list);
pic.setSelected(0);
}
public class Pickers implements Serializable {
private static final long serialVersionUID =1L;
private StringshowConetnt;
private StringshowId;
public String getShowConetnt() {
return showConetnt;
}
public String getShowId() {
return showId;
}
public Pickers(String showConetnt, String showId) {
super();
this.showConetnt = showConetnt;
this.showId = showId;
}
public Pickers() {
super();
}
}
// 滚动选择器选中事件
PickerScrollView.onSelectListenerpickerListener =new PickerScrollView.onSelectListener() {
@Override
public void onSelect(Pickers pickers) {
String showConetnt = pickers.getShowConetnt();
Log.e("+++++","选择：" + pickers.getShowId() +"--银行："
+ pickers.getShowConetnt());
often.setText(showConetnt);
}
};
