给Recyclerview添加自定义分割线

用mRecyclerView.addItemDecoration()来加入分割线，谷歌没有提供默认的分割线需要我们继承RecyclerView.ItemDecoration来自定义分割线：

public class DividerItemDecoration extends RecyclerView.ItemDecoration {

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

public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;

public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;

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 if (mOrientation == HORIZONTAL_LIST){
        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

}

使用方式：

rlView.addItemDecoration(new DividerItemDecoration(this,DividerItemDecoration.VERTICAL_LIST));

style里加入：

@drawable/line_drawable

line_deawable.xml代码如下：