mRecyclerView.addItemDecoration(new RecyclerViewDivider(mContext, LinearLayoutManager.VERTICAL));

 mRecyclerView.addItemDecoration(new RecyclerViewDivider(

     mContext, LinearLayoutManager.VERTICAL, R.drawable.divider_mileage));

 mRecyclerView.addItemDecoration(new RecyclerViewDivider(

     mContext, LinearLayoutManager.VERTICAL, 10, ContextCompat.getColor(mContext, R.color.divide_gray_color)));

 package utils;

 import android.content.Context;

 import android.content.res.TypedArray;

 import android.graphics.Canvas;

 import android.graphics.Paint;

 import android.graphics.Rect;

 import android.graphics.drawable.Drawable;

 import android.support.v4.content.ContextCompat;

 import android.support.v7.widget.LinearLayoutManager;

 import android.support.v7.widget.RecyclerView;

 import android.view.View;

 /**

  * Created by ${火龙裸先生} on 2016/10/29.

  * 邮箱：791335000@qq.com

  */

 public class RecyclerViewDivider extends RecyclerView.ItemDecoration {

     private Paint mPaint;

     private Drawable mDivider;

     private int mDividerHeight = 2;//分割线高度，默认为1px

     private int mOrientation;//列表的方向：LinearLayoutManager.VERTICAL或LinearLayoutManager.HORIZONTAL

     private static final int[] ATTRS = new int[]{android.R.attr.listDivider};

     /**

      * 默认分割线：高度为2px，颜色为灰色

      *

      * @param context

      * @param orientation 列表方向

      */

     public RecyclerViewDivider(Context context, int orientation) {

         if (orientation != LinearLayoutManager.VERTICAL && orientation != LinearLayoutManager.HORIZONTAL) {

             throw new IllegalArgumentException("请输入正确的参数！");

         }

         mOrientation = orientation;

         final TypedArray a = context.obtainStyledAttributes(ATTRS);

         mDivider = a.getDrawable(0);

         a.recycle();

     }

     /**

      * 自定义分割线

      *

      * @param context

      * @param orientation 列表方向

      * @param drawableId  分割线图片

      */

     public RecyclerViewDivider(Context context, int orientation, int drawableId) {

         this(context, orientation);

         mDivider = ContextCompat.getDrawable(context, drawableId);

         mDividerHeight = mDivider.getIntrinsicHeight();

     }

     /**

      * 自定义分割线

      *

      * @param context

      * @param orientation   列表方向

      * @param dividerHeight 分割线高度

      * @param dividerColor  分割线颜色

      */

     public RecyclerViewDivider(Context context, int orientation, int dividerHeight, int dividerColor) {

         this(context, orientation);

         mDividerHeight = dividerHeight;

         mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);

         mPaint.setColor(dividerColor);

         mPaint.setStyle(Paint.Style.FILL);

     }

     //获取分割线尺寸

     @Override

     public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {

         super.getItemOffsets(outRect, view, parent, state);

         outRect.set(0, 0, 0, mDividerHeight);

     }

     //绘制分割线

     @Override

     public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {

         super.onDraw(c, parent, state);

         if (mOrientation == LinearLayoutManager.VERTICAL) {

             drawVertical(c, parent);

         } else {

             drawHorizontal(c, parent);

         }

     }

     //绘制横向 item 分割线

     private void drawHorizontal(Canvas canvas, RecyclerView parent) {

         final int left = parent.getPaddingLeft();

         final int right = parent.getMeasuredWidth() - parent.getPaddingRight();

         final int childSize = parent.getChildCount();

         for (int i = 0; i < childSize; i++) {

             final View child = parent.getChildAt(i);

             RecyclerView.LayoutParams layoutParams = (RecyclerView.LayoutParams) child.getLayoutParams();

             final int top = child.getBottom() + layoutParams.bottomMargin;

             final int bottom = top + mDividerHeight;

             if (mDivider != null) {

                 mDivider.setBounds(left, top, right, bottom);

                 mDivider.draw(canvas);

             }

             if (mPaint != null) {

                 canvas.drawRect(left, top, right, bottom, mPaint);

             }

         }

     }

     //绘制纵向 item 分割线

     private void drawVertical(Canvas canvas, RecyclerView parent) {

         final int top = parent.getPaddingTop();

         final int bottom = parent.getMeasuredHeight() - parent.getPaddingBottom();

         final int childSize = parent.getChildCount();

         for (int i = 0; i < childSize; i++) {

             final View child = parent.getChildAt(i);

             RecyclerView.LayoutParams layoutParams = (RecyclerView.LayoutParams) child.getLayoutParams();

             final int left = child.getRight() + layoutParams.rightMargin;

             final int right = left + mDividerHeight;

             if (mDivider != null) {

                 mDivider.setBounds(left, top, right, bottom);

                 mDivider.draw(canvas);

             }

             if (mPaint != null) {

                 canvas.drawRect(left, top, right, bottom, mPaint);

             }

         }

     }

 }