public class DividerItemDecoration extends RecyclerView.ItemDecoration{ // 寫右邊字的畫筆(具體信息) private Paint mPaint; // 寫左邊日期字的畫筆( 時間 + 日期) private Paint mPaint1; private Paint mPaint2; private Paint mPaint3; // 左 上偏移長度 private int itemView_leftinterval; private int itemView_topinterval; // 軸點半徑 private int circle_radius; // 圖標 private Bitmap mIcon; //月份合集(使用時需要設置) private List<String> monthList= new ArrayList<>(); //年份合集(使用時需要設置) private List<String> yearList= new ArrayList<>(); public void setMonthList(List<String> monthList) {  this.monthList = monthList; } public void setYearList(List<String> yearList) {  this.yearList = yearList; } // 在構造函數(shù)里進行繪制的初始化，如畫筆屬性設置等 public DividerItemDecoration(Context context) {  // 軸點畫筆(紅色)  mPaint = new Paint();  mPaint.setColor(Color.rgb(58, 154, 239));  mPaint.setStyle(Paint.Style.STROKE);  mPaint.setStrokeWidth(3);  // 左邊時間文本畫筆(藍色)  // 此處設置了兩只分別設置 時分 & 年月  mPaint1 = new Paint();  mPaint1.setColor(Color.BLACK);  mPaint1.setTextSize(30);  mPaint2 = new Paint();  mPaint2.setColor(context.getResources().getColor(R.color.divider));  mPaint2.setTextSize(26);  mPaint3 = new Paint();  mPaint3.setColor(Color.rgb(58, 154, 239));  mPaint3.setTextSize(20);  // 賦值ItemView的左偏移長  itemView_leftinterval = 150;  // 賦值ItemView的上偏移長度  itemView_topinterval = 30;  // 賦值軸點圓的半徑為10  circle_radius = 8; } // 重寫getItemOffsets（）方法 // 作用：設置ItemView 左 & 上偏移長度 @Override public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {  super.getItemOffsets(outRect, view, parent, state);  // 設置ItemView的左 & 上偏移長度分別為150 px & 30px,即此為onDraw()可繪制的區(qū)域  outRect.set(itemView_leftinterval, itemView_topinterval, 0, 0); } // 重寫onDraw（） // 作用:在間隔區(qū)域里繪制時光軸線 & 時間文本 @Override public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {  super.onDraw(c, parent, state);  // 獲取RecyclerView的Child view的個數(shù)  int childCount = parent.getChildCount();  // 遍歷每個Item，分別獲取它們的位置信息，然后再繪制對應的分割線  for (int i = 0; i < childCount; i++) {   // 獲取每個Item對象   View child = parent.getChildAt(i);   View lastChild = null;   if (i > 0) {    lastChild = parent.getChildAt(i - 1);   }   /**    * 繪制軸點    */   // 軸點 = 圓 = 圓心(x,y) 位置可以根據(jù)需求來調節(jié)   float centerx = child.getLeft() - itemView_leftinterval / 4;   float centery = child.getTop() + itemView_topinterval +10;   // 繪制軸點圓   c.drawCircle(centerx, centery, circle_radius, mPaint);   /**    * 繪制上半軸線(x軸是保持不變的)    */   // 上端點坐標(x,y)   float upLine_up_x = centerx;   float upLine_up_y = 0;   if (i>0){     upLine_up_y = lastChild.getBottom();   }else {     upLine_up_y = centery - itemView_topinterval;   }   // 下端點坐標(x,y)   float upLine_bottom_x = centerx;   float upLine_bottom_y = centery - circle_radius;   //繪制上半部軸線   c.drawLine(upLine_up_x, upLine_up_y, upLine_bottom_x, upLine_bottom_y, mPaint);   /**    * 繪制下半軸線,最后一個不畫下半軸    */   if (i <childCount-1){    // 上端點坐標(x,y)    float bottomLine_up_x = centerx;    float bottom_up_y = centery + circle_radius;    // 下端點坐標(x,y)    float bottomLine_bottom_x = centerx;    float bottomLine_bottom_y = child.getBottom();    //繪制下半部軸線    c.drawLine(bottomLine_up_x, bottom_up_y, bottomLine_bottom_x, bottomLine_bottom_y, mPaint);   }   /**    * 繪制左邊時間文本    */   // 獲取每個Item的位置   int index = parent.getChildAdapterPosition(child);   // 設置文本起始坐標   float Text_x = child.getLeft() - itemView_leftinterval * 5 / 6;   float Text_y = upLine_bottom_y;   // 根據(jù)Item位置設置時間文本   switch (index) {    case (0):     // 設置日期繪制位置     c.drawText(monthList.get(0), Text_x, Text_y, mPaint1);     c.drawText(yearList.get(0), Text_x + 8, Text_y + 28, mPaint2);     break;    case (1):     // 設置日期繪制位置     c.drawText(monthList.get(1), Text_x, Text_y, mPaint1);     c.drawText(yearList.get(1), Text_x + 8, Text_y + 28, mPaint2);     break;    case (2):     // 設置日期繪制位置     if (TextUtils.isEmpty(yearList.get(2))){      c.drawText(monthList.get(2), Text_x, Text_y, mPaint3);     }else {      c.drawText(monthList.get(2), Text_x, Text_y, mPaint1);      c.drawText(yearList.get(2), Text_x + 8, Text_y + 28, mPaint2);     }     break;    case (3):     // 設置日期繪制位置     c.drawText(monthList.get(3), Text_x, Text_y, mPaint1);     c.drawText(yearList.get(3), Text_x + 8, Text_y + 28, mPaint2);     break;    case (4):     // 設置日期繪制位置     c.drawText(monthList.get(4), Text_x, Text_y, mPaint1);     c.drawText(yearList.get(4), Text_x + 8, Text_y + 28, mPaint2);     break;    default:c.drawText("結束", Text_x, Text_y, mPaint1);   }  } }}

DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(this);  dividerItemDecoration.setMonthList(monthList);  dividerItemDecoration.setYearList(yearList);  mRecyclerView.addItemDecoration(dividerItemDecoration);