GridLayoutManager manager = new GridLayoutManager(this, 1); 
 recyclerView.setLayoutManager(manager);

public class NameBean { 
 String name; 
 public String getName() { 
 return name; 
 } 
 public void setName(String name) { 
 this.name = name; 
 } 
}

public class SectionDecoration extends RecyclerView.ItemDecoration { 
 private static final String TAG = "SectionDecoration"; 
 private List<NameBean> dataList; 
 private DecorationCallback callback; 
 private TextPaint textPaint; 
 private Paint paint; 
 private int topGap; 
 private int alignBottom; 
 private Paint.FontMetrics fontMetrics; 
 public SectionDecoration(List<NameBean> dataList, Context context, DecorationCallback decorationCallback) { 
 Resources res = context.getResources(); 
 this.dataList = dataList; 
 this.callback = decorationCallback; 
 //設(shè)置懸浮欄的畫筆---paint 
 paint = new Paint(); 
 paint.setColor(res.getColor(R.color.colorGray)); 
 //設(shè)置懸浮欄中文本的畫筆 
 textPaint = new TextPaint(); 
 textPaint.setAntiAlias(true); 
 textPaint.setTextSize(DensityUtil.dip2px(context, 14)); 
 textPaint.setColor(Color.DKGRAY); 
 textPaint.setTextAlign(Paint.Align.LEFT); 
 fontMetrics = new Paint.FontMetrics(); 
 //決定懸浮欄的高度等 
 topGap = res.getDimensionPixelSize(R.dimen.sectioned_top); 
 //決定文本的顯示位置等 
 alignBottom = res.getDimensionPixelSize(R.dimen.sectioned_alignBottom); 
 } 
 @Override 
 public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) { 
 super.getItemOffsets(outRect, view, parent, state); 
 int pos = parent.getChildAdapterPosition(view); 
 Log.i(TAG, "getItemOffsets：" + pos); 
 String groupId = callback.getGroupId(pos); 
 if (groupId.equals("-1")) return; 
 //只有是同一組的第一個(gè)才顯示懸浮欄 
 if (pos == 0 || isFirstInGroup(pos)) { 
 outRect.top = topGap; 
 if (dataList.get(pos).getName() == "") { 
 outRect.top = 0; 
 } 
 } else { 
 outRect.top = 0; 
 } 
 } 
 @Override 
 public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) { 
 super.onDraw(c, parent, state); 
 int left = parent.getPaddingLeft(); 
 int right = parent.getWidth() - parent.getPaddingRight(); 
 int childCount = parent.getChildCount(); 
 for (int i = 0; i < childCount; i++) { 
 View view = parent.getChildAt(i); 
 int position = parent.getChildAdapterPosition(view); 
 String groupId = callback.getGroupId(position); 
 if (groupId.equals("-1")) return; 
 String textLine = callback.getGroupFirstLine(position).toUpperCase(); 
 if (textLine == "") { 
 float top = view.getTop(); 
 float bottom = view.getTop(); 
 c.drawRect(left, top, right, bottom, paint); 
 return; 
 } else { 
 if (position == 0 || isFirstInGroup(position)) { 
  float top = view.getTop() - topGap; 
  float bottom = view.getTop(); 
  //繪制懸浮欄 
  c.drawRect(left, top - topGap, right, bottom, paint); 
  //繪制文本 
  c.drawText(textLine, left, bottom, textPaint); 
 } 
 } 
 } 
 } 
 @Override 
 public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) { 
 super.onDrawOver(c, parent, state); 
 int itemCount = state.getItemCount(); 
 int childCount = parent.getChildCount(); 
 int left = parent.getPaddingLeft(); 
 int right = parent.getWidth() - parent.getPaddingRight(); 
 float lineHeight = textPaint.getTextSize() + fontMetrics.descent; 
 String preGroupId = ""; 
 String groupId = "-1"; 
 for (int i = 0; i < childCount; i++) { 
 View view = parent.getChildAt(i); 
 int position = parent.getChildAdapterPosition(view); 
 preGroupId = groupId; 
 groupId = callback.getGroupId(position); 
 if (groupId.equals("-1") || groupId.equals(preGroupId)) continue; 
 String textLine = callback.getGroupFirstLine(position).toUpperCase(); 
 if (TextUtils.isEmpty(textLine)) continue; 
 int viewBottom = view.getBottom(); 
 float textY = Math.max(topGap, view.getTop()); 
 //下一個(gè)和當(dāng)前不一樣移動(dòng)當(dāng)前 
 if (position + 1 < itemCount) { 
 String nextGroupId = callback.getGroupId(position + 1); 
 //組內(nèi)最后一個(gè)view進(jìn)入了header 
 if (nextGroupId != groupId && viewBottom < textY) { 
  textY = viewBottom; 
 } 
 } 
 //textY - topGap決定了懸浮欄繪制的高度和位置 
 c.drawRect(left, textY - topGap, right, textY, paint); 
 //left+2*alignBottom 決定了文本往左偏移的多少（加-->向左移） 
 //textY-alignBottom 決定了文本往右偏移的多少 (減-->向上移) 
 c.drawText(textLine, left + 2 * alignBottom, textY - alignBottom, textPaint); 
 } 
 } 
 /**
 * 判斷是不是組中的第一個(gè)位置
 *
 * @param pos
 * @return
 */ 
 private boolean isFirstInGroup(int pos) { 
 if (pos == 0) { 
 return true; 
 } else { 
 // 因?yàn)槭歉鶕?jù) 字符串內(nèi)容的相同與否 來(lái)判斷是不是同意組的，所以此處的標(biāo)記id 要是String類型 
 // 如果你只是做聯(lián)系人列表，懸浮框里顯示的只是一個(gè)字母，則標(biāo)記id直接用 int 類型就行了 
 String prevGroupId = callback.getGroupId(pos - 1); 
 String groupId = callback.getGroupId(pos); 
 //判斷前一個(gè)字符串 與 當(dāng)前字符串 是否相同 
 if (prevGroupId.equals(groupId)) { 
 return false; 
 } else { 
 return true; 
 } 
 } 
 } 
 //定義一個(gè)借口方便外界的調(diào)用 
 interface DecorationCallback { 
 String getGroupId(int position); 
 String getGroupFirstLine(int position); 
 } 
}

private void setPullAction(List<WaitMVBean.DataBean.ComingBean> comingslist) { 
 dataList = new ArrayList<>(); 
 for (int i = 0; i < comingslist.size(); i++) { 
 NameBean nameBean = new NameBean(); 
 String name0 = comingslist.get(i).getComingTitle(); 
 nameBean.setName(name0); 
 dataList.add(nameBean); 
 } 
 }

recyclerView.addItemDecoration(new SectionDecoration(dataList,mContext, new SectionDecoration.DecorationCallback() { 
 //返回標(biāo)記id (即每一項(xiàng)對(duì)應(yīng)的標(biāo)志性的字符串) 
 @Override 
 public String getGroupId(int position) { 
  if(dataList.get(position).getName()!=null) { 
  return dataList.get(position).getName(); 
  } 
  return "-1"; 
 } 
  //獲取同組中的第一個(gè)內(nèi)容 
 @Override 
 public String getGroupFirstLine(int position) { 
  if(dataList.get(position).getName()!=null) { 
  return dataList.get(position).getName(); 
  } 
  return ""; 
 } 
 }));