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2020
10-08

Android自定义RecyclerView实现不固定刻度的刻度尺

本文实例为大家分享了自定义RecyclerView实现不固定刻度的刻度尺的具体代码，供大家参考，具体内容如下

##不均匀刻度效果图

##等比例刻度效果图

实现功能目前

1、实现类似日期/分类等大小不固定的水平刻度尺效果
2、实现标准刻度尺效果
3、监听RecyclerView滑动时居中条目
4、去掉边缘阴影

定义RecyclerView

public class CenterRecyclerView extends RecyclerView {

//设置RecyclerView的速度
 private static final int MAXIMUM_FLING_VELOCITY = 3000;
//画中轴线
 private Paint mCenterLinePaint;
 private Context context;
 private CenterLayoutManager mLayoutManager;
 private Paint mTextPaint;
 private String text = "";
 private String textUnit = "";
 private Paint mTextUnitPaint;
 private int mWidth;
 private int mHeight;
 private int mLineStartY;
 private int mLineEndY;
 private int mTextStartY;

 public CenterRecyclerView(@NonNull Context context) {
  this(context, null);
 }

 public CenterRecyclerView(@NonNull Context context, @Nullable AttributeSet attrs) {
  this(context, attrs, -1);
 }

 public CenterRecyclerView(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
  super(context, attrs, defStyleAttr);
  init(context, attrs);
 }

 private void init(Context context, AttributeSet attrs) {
  this.context = context;
  initPaint();
 }

 public void setTypeface(Typeface typeface) {
  mTextPaint.setTypeface(typeface);
  mTextUnitPaint.setTypeface(typeface);
 }

 private void initPaint() {
  mCenterLinePaint = new Paint();
  mCenterLinePaint.setAntiAlias(true);
  mCenterLinePaint.setStrokeWidth(ScreenUtil.dip2px(context, 4));
  mCenterLinePaint.setTextAlign(Paint.Align.CENTER);
  mCenterLinePaint.setColor(0xff6e9fff);

  mTextUnitPaint = new Paint();
  mTextUnitPaint.setStyle(Paint.Style.FILL);
  mTextUnitPaint.setStrokeWidth(ScreenUtil.dip2px(context, 4));
  mTextUnitPaint.setTextSize(ScreenUtil.dip2px(context, 15));
  mTextUnitPaint.setColor(Color.parseColor("#DD5F00"));

  mTextPaint = new Paint();
  mTextPaint.setStyle(Paint.Style.FILL);
  mTextPaint.setStrokeWidth(ScreenUtil.dip2px(context, 4));
  mTextPaint.setTextSize(ScreenUtil.dip2px(context, 60));
  mTextPaint.setColor(Color.parseColor("#DD5F00"));
  mTextPaint.setTextAlign(Paint.Align.CENTER);
 }

 @Override
 public void addOnScrollListener(@NonNull OnScrollListener listener) {
  super.addOnScrollListener(listener);
  postInvalidate();
 }

 @Override
 protected void onMeasure(int widthSpec, int heightSpec) {
  super.onMeasure(widthSpec, heightSpec);

 }

//获取相关参数
 @Override
 protected void onLayout(boolean changed, int l, int t, int r, int b) {
  super.onLayout(changed, l, t, r, b);
  mWidth = getWidth();
  mHeight = getHeight();
  int lineHeight = ScreenUtil.dip2px(context, 58);
  mLineStartY = mHeight / 2 - lineHeight / 2;
  mLineEndY = mHeight / 2 + lineHeight / 2;
  mTextStartY = mHeight / 2 - ScreenUtil.dip2px(context, 55);
 }

 @Override
 public void draw(Canvas c) {
  super.draw(c);
  Log.d("szjjyh", "draw: " + getWidth());
  drawCenterLine(c);
  drawText(c);
 }

//画线
 private void drawCenterLine(Canvas canvas) {
  canvas.drawLine(mWidth / 2, mLineStartY, mWidth / 2, mLineEndY, mCenterLinePaint);
 }

//画字/画单位
 private void drawText(Canvas c) {
  c.drawText(text, mWidth / 2, mTextStartY, mTextPaint);
  if (textUnit != null && textUnit.length() != 0) {
   float textWidth = mTextPaint.measureText(text);
   c.drawText(textUnit, (mWidth + textWidth) / 2, mTextStartY, mTextUnitPaint);
  }
 }

 public String getText() {
  return text;
 }

 public void setText(String text) {
  if (text == null) {
   return;
  }
  this.text = text;
 }

 public String getTextUnit() {
  return textUnit;
 }

 public void setTextUnit(String textUnit) {
  if (textUnit == null) {
   return;
  }
  this.textUnit = textUnit;
 }

 @Override
 public void setAdapter(@Nullable Adapter adapter) {
  super.setAdapter(adapter);
 }

 @Override
 public void setLayoutManager(@Nullable LayoutManager layout) {
  super.setLayoutManager(layout);
  mLayoutManager = (CenterLayoutManager) layout;
 }

 @Override
 public boolean fling(int velocityX, int velocityY) {
  velocityX = solveVelocity(velocityX);
  velocityY = solveVelocity(velocityY);
  return super.fling(velocityX, velocityY);
 }

 private int solveVelocity(int velocity) {
  if (velocity > 0) {
   return Math.min(velocity, MAXIMUM_FLING_VELOCITY);
  } else {
   return Math.max(velocity, -MAXIMUM_FLING_VELOCITY);
  }
 }

// @Override
// protected float getLeftFadingEdgeStrength() {
//  return 0;
// }
}

定义LinearLayoutManager

public class CenterLayoutManager extends LinearLayoutManager {
 public CenterLayoutManager(Context context) {
  super(context);
 }

 public CenterLayoutManager(Context context, int orientation, boolean reverseLayout) {
  super(context, orientation, reverseLayout);
 }

 public CenterLayoutManager(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
  super(context, attrs, defStyleAttr, defStyleRes);
 }
//计算偏移量自己适配
 @Override
 public void scrollToPosition(int position) {
  scrollToPositionWithOffset(position,-15);
 }

 @Override
 public void scrollToPositionWithOffset(int position, int offset) {
  super.scrollToPositionWithOffset(position, offset);
 }
 @Override
 public void smoothScrollToPosition(RecyclerView recyclerView, RecyclerView.State state, int position) {
  RecyclerView.SmoothScroller smoothScroller = new CenterSmoothScroller(recyclerView.getContext());
  smoothScroller.setTargetPosition(position);
  startSmoothScroll(smoothScroller);
 }

 public void smoothScrollToPosition(RecyclerView recyclerView, int position) {
  RecyclerView.SmoothScroller smoothScroller = new CenterSmoothScroller(recyclerView.getContext());
  smoothScroller.setTargetPosition(position);
  startSmoothScroll(smoothScroller);
 }


 private static class CenterSmoothScroller extends LinearSmoothScroller {

  CenterSmoothScroller(Context context) {
   super(context);
  }

//滑动到中间位置
  @Override
  public int calculateDtToFit(int viewStart, int viewEnd, int boxStart, int boxEnd, int snapPreference) {
   return (boxStart + (boxEnd - boxStart) / 2) - (viewStart + (viewEnd - viewStart) / 2);
  }
//滚动速度设置
  @Override
  protected float calculateSpeedPerPixel(DisplayMetrics displayMetrics) {
   return 4;
  }

  @Override
  protected int getVerticalSnapPreference() {
   return super.getVerticalSnapPreference();
  }
 }
 
}

滑动事件监听

public class CenterScrollListener extends RecyclerView.OnScrollListener {

 private CenterLayoutManager mLayoutManager;
 RecyclerView recyclerView;
 private int mPosition;
 private double intScrollState;
 private int mFirstItemPosition1;
 private int mLastItemPosition1;
 private boolean is_Stop;
 private String TAG = "CenterScrollListener";
 private double is_playSound;

 public CenterScrollListener(OnItemCenterScrollistner onItemCenterScrollistner) {
  this.onItemCenterScrollistner = onItemCenterScrollistner;
 }

 public void onScrollStateChanged(@NonNull RecyclerView recyclerView, int newState) {
  init(recyclerView);
  intScrollState = newState;
  is_Stop = false;

  if (intScrollState == RecyclerView.SCROLL_STATE_IDLE) {
   Log.e(TAG, "onScrollStateChanged: 11111:"+mPosition);
   CeterScroll(0, mPosition);
  }
 }

 public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
  init(recyclerView);
  int x = Math.abs(dx);
  if (!is_Stop && x <= 1) {
   is_Stop = true;
   if (dx >= 0) {
    mPosition = (mFirstItemPosition1 + mLastItemPosition1) / 2;
    View childAt = mLayoutManager.findViewByPosition(mPosition);
    if (childAt.getLeft() < ScreenUtil.getScreenWidth(recyclerView.getContext()) / 2) {
     mPosition = mPosition + 1;
    }
    Log.e(TAG, "111111: w:" + childAt.getWidth() + " :l:" +
      childAt.getLeft() + " :r:" + childAt.getRight());
   } else {
    mPosition = (mFirstItemPosition1 + mLastItemPosition1) / 2;
    View childAt = mLayoutManager.findViewByPosition(mPosition);
    if (childAt.getLeft() > ScreenUtil.getScreenWidth(recyclerView.getContext()) / 2) {
     mPosition = mPosition - 1;
    }
   }
  }
  CeterScroll(x, mPosition);
 }

//事件监听
 private void init(@NonNull RecyclerView recyclerView) {
  this.recyclerView = recyclerView;
  if (mLayoutManager == null) {
   mLayoutManager = (CenterLayoutManager) recyclerView.getLayoutManager();
  }
  int firstItemPosition = mLayoutManager.findFirstVisibleItemPosition();
  int lastItemPosition = mLayoutManager.findLastVisibleItemPosition();
  mFirstItemPosition1 = mLayoutManager.findFirstCompletelyVisibleItemPosition();
  mLastItemPosition1 = mLayoutManager.findLastCompletelyVisibleItemPosition();
  mPosition = (mFirstItemPosition1 + mLastItemPosition1) / 2;

  if (is_playSound != mPosition) {
   is_playSound = mPosition;
   int count = mLayoutManager.getItemCount();
//     soundpool.play(soundmap.get(1), 1, 1, 0, 0, 1);
   if (onItemCenterScrollistner != null) {
//中间条目事件监听
    onItemCenterScrollistner.onItemCenterScrollistner(mLastItemPosition1, mPosition,count);
   }
  }

//目前由于要实现灰色条目当条目间距为10dp,屏幕宽度360时不能继续滑动
  if (mPosition <= 18) {
   CeterScroll(0, 18);
  }
 }

//速度变小时自动滚动到中间位置
 private void CeterScroll(int dx, int position) {
  if ((intScrollState == RecyclerView.SCROLL_STATE_SETTLING || intScrollState
    == RecyclerView.SCROLL_STATE_IDLE) && Math.abs(dx) <= 1) {
   mLayoutManager.smoothScrollToPosition(recyclerView, position);
  }
 }

 OnItemCenterScrollistner onItemCenterScrollistner;

 public void setOnItemCenterScrollistner(OnItemCenterScrollistner onItemCenterScrollistner) {
  this.onItemCenterScrollistner = onItemCenterScrollistner;
 }

 public interface OnItemCenterScrollistner {
  void onItemCenterScrollistner(int lastItemPosition1, int position, int count);
 }

adpater实现

public class DateAdapter extends BaseRecyclerAdapter<CalendarDateBean> {

 private static final int layoutId = R.layout.view_item_date;

 public DateAdapter(Context context, List<CalendarDateBean> datas) {
  super(context, datas, layoutId);
 }

 @Override
 protected void bindData(BaseViewHolder holder, CalendarDateBean data, int position) {
  if (data.getDay() == 1) {
//R.id.tv_1为线需要居中否则和中轴线不会完全对称 R.id.tv_2为大刻度文字
   holder.getView(R.id.tv_1).setScaleX(2F);
   holder.setText(R.id.tv_2, data.getMonth() + "月");
   holder.getView(R.id.tv_2).setVisibility(View.VISIBLE);
   holder.getView(R.id.tv_1).setBackgroundColor(Color.parseColor("#ffffff"));
  } else if (data.getDay() ==-1){
   holder.getView(R.id.tv_1).setScaleX(1F);
   holder.getView(R.id.tv_2).setVisibility(View.GONE);
   holder.getView(R.id.tv_1).setBackgroundColor(Color.parseColor("#222222"));
  }else {
   holder.getView(R.id.tv_1).setScaleX(1F);
   holder.getView(R.id.tv_2).setVisibility(View.GONE);
   holder.getView(R.id.tv_1).setBackgroundColor(Color.parseColor("#ffffff"));
  }
 }
 
}

activity 加载view展示

private void initRecyclerView() {
//此处试配时注意item10dp 宽度360 计算发放 360/10/2得到记得适配
  for (int i = 0; i < 18; i++) {
   TimeBean timeBean = new TimeBean();
   mList.add(timeBean);
  }
  for (int i = 0; i < 1440; i++) {
   int minute = i % 60;
   int hour = i / 60;
   if (CalendarUtil.getHourTime()==hour&&CalendarUtil.getMinuteTime()==minute){
    mPostion = i;
   }
   TimeBean timeBean = new TimeBean();
   timeBean.setHour(hour);
   timeBean.setMinute(minute);
   timeBean.setTimeDate(CalendarUtil.getHourToMinute(hour,minute));
   mList.add(timeBean);
  }
  for (int i = 0; i < 18; i++) {
   TimeBean timeBean = new TimeBean();
//   timeBean.setMinute(-1);
   mList.add(timeBean);
  }

  rv_data = findViewById(R.id.rv_data);
  mAdapter = new TimeAdapter(this, mList);
  rv_data.setAdapter(mAdapter);
//设置字体
  rv_data.setTypeface(Typeface.createFromAsset(getAssets(), "fonts/dincond_boldalternate.ttf"));
  CenterLayoutManager layoutManager = new CenterLayoutManager(this);
  layoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);
  rv_data.setLayoutManager(layoutManager);

  rv_data.scrollToPosition(mPostion);
  rv_data.addOnScrollListener(new CenterScrollListener((lastItemPosition, position,count) -> {
//更新文本和单位
   rv_data.setText(mList.get(position).getTimeDate());
   if (mList.get(position).getHour()>12){
    rv_data.setTextUnit("PM");
   }else {
    rv_data.setTextUnit("AM");
   }
  }));

 }

实现了基本代码全部写了。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持自学编程网。

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