content: package com.wm.remusic.widget;
  
  import android.content.Context;
  import android.content.res.TypedArray;
  import android.graphics.Canvas;
  import android.graphics.Rect;
  import android.graphics.drawable.Drawable;
  import android.support.v7.widget.LinearLayoutManager;
  import android.support.v7.widget.RecyclerView;
  import android.view.View;
  
  /**
   * Created by wm on 2016/1/22.
   */
  public class DividerItemDecoration extends RecyclerView.ItemDecoration {
  
      public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;
      public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;
      private static final int[] ATTRS = new int[]{
              android.R.attr.listDivider
      };
      private Drawable mDivider;
  
      private int mOrientation;
  
      public DividerItemDecoration(Context context, int orientation) {
          final TypedArray a = context.obtainStyledAttributes(ATTRS);
          mDivider = a.getDrawable(0);
          a.recycle();
          setOrientation(orientation);
      }
  
      public void setOrientation(int orientation) {
          if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST) {
              throw new IllegalArgumentException("invalid orientation");
          }
          mOrientation = orientation;
      }
  
      @Override
      public void onDraw(Canvas c, RecyclerView parent) {
  
          if (mOrientation == VERTICAL_LIST) {
              drawVertical(c, parent);
          } else {
              drawHorizontal(c, parent);
          }
  
      }
  
  
      public void drawVertical(Canvas c, RecyclerView parent) {
          final int left = parent.getPaddingLeft();
          final int right = parent.getWidth() - parent.getPaddingRight();
  
          final int childCount = parent.getChildCount();
          for (int i = 0; i < childCount; i++) {
              final View child = parent.getChildAt(i);
              android.support.v7.widget.RecyclerView v = new android.support.v7.widget.RecyclerView(parent.getContext());
              final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
                      .getLayoutParams();
              final int top = child.getBottom() + params.bottomMargin;
              final int bottom = top + mDivider.getIntrinsicHeight();
              mDivider.setBounds(left, top, right, bottom);
              mDivider.draw(c);
          }
      }
  
      public void drawHorizontal(Canvas c, RecyclerView parent) {
          final int top = parent.getPaddingTop();
          final int bottom = parent.getHeight() - parent.getPaddingBottom();
  
          final int childCount = parent.getChildCount();
          for (int i = 0; i < childCount; i++) {
              final View child = parent.getChildAt(i);
              final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
                      .getLayoutParams();
              final int left = child.getRight() + params.rightMargin;
              final int right = left + mDivider.getIntrinsicHeight();
              mDivider.setBounds(left, top, right, bottom);
              mDivider.draw(c);
          }
      }
  
      @Override
      public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent) {
          if (mOrientation == VERTICAL_LIST) {
              outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
          } else {
              outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
          }
      }
  }
  