垂直方向：CommItemDecoration.createVertical( Color.YELLOW,30)
水平方向：CommItemDecoration.createHorizontal( Color.YELLOW,30)
```
public class CommItemDecorationextends RecyclerView.ItemDecoration {
private static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;
private static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;
private int mSpace =1;
private RectmRect =new Rect(0,0,0,0);
private PaintmPaint =new Paint();
private int mOrientation;
private CommItemDecoration(int orientation, @ColorInt int color, int space) {
mOrientation = orientation;
if(space>0){
mSpace = space;
}
mPaint.setColor(color);
}
@Override
public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
super.onDraw(c, parent, state);
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);
final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
.getLayoutParams();
final int top = child.getBottom() + params.bottomMargin;
final int bottom = top +mSpace;
mRect.set(left,top,right,bottom);
c.drawRect(mRect,mPaint);
}
}
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 +mSpace;
mRect.set(left, top, right, bottom);
c.drawRect(mRect,mPaint);
}
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
super.getItemOffsets(outRect, view, parent, state);
if (mOrientation ==VERTICAL_LIST) {
outRect.set(0, 0, 0,mSpace);
}else {
outRect.set(0, 0, mSpace, 0);
}
}
public static CommItemDecorationcreateVertical(@ColorInt int color, int height){
return new CommItemDecoration(VERTICAL_LIST,color,height);
}
public static CommItemDecorationcreateHorizontal(@ColorInt int color, int width){
return new CommItemDecoration(HORIZONTAL_LIST,color,width);
}
}
```