Android RecyclerView 设置分割线(item头部也绘制)
public class DividerGridItemDecoration extends RecyclerView.ItemDecoration {
private static final int[] ATTRS = new int[]{};
private Drawable mDivider;
public DividerGridItemDecoration(Context context) {
final TypedArray a = (ATTRS);
mDivider = (0);
();
}
@Override
public void onDraw(Canvas c, RecyclerView parent, state) {
drawHorizontal(c, parent);
drawVertical(c, parent);
}
private int getSpanCount(RecyclerView parent) {
// 列数
int spanCount = -1;
layoutManager = ();
if (layoutManager instanceof GridLayoutManager) {
spanCount = ((GridLayoutManager) layoutManager).getSpanCount();
} else if (layoutManager instanceof StaggeredGridLayoutManager) {
spanCount = ((StaggeredGridLayoutManager) layoutManager)
.getSpanCount();
}
return spanCount;
}
public void drawHorizontal(Canvas c, RecyclerView parent) {
int childCount = ();
int column_num = getSpanCount(parent);
for (int i = 0; i < childCount; i++) {
final View child = (i);
final params = () child
.getLayoutParams();
final int left = () - ;
final int right = () +
+ ();
// final int top = () + ;
// final int bottom = top + ();
// (left, top, right, bottom);
// (c);
int top = 0;
int bottom = 0;
if ((i / column_num) == 0) {
//画item最上面的分割线
top = 0;
bottom = top + ();
(left, top, right, bottom);
(c);
//画item下面的分割线
top = () + ;
bottom = top + ();
(left, top, right, bottom);
(c);
} else {
//画item下面的分割线
top = () + ;
bottom = top + ();
(left, top, right, bottom);
(c);
}
}
}
public void drawVertical(Canvas c, RecyclerView parent) {
final int childCount = ();
int column_num = getSpanCount(parent);
for (int i = 0; i < childCount; i++) {
final View child = (i);
final params = () child
.getLayoutParams();
final int top = () - ;
final int bottom = () + ;
// final int left = () + ;
// final int right = left + ();
// (left, top, right, bottom);
// (c);
int left = 0;
int right = 0;
if ((i % column_num) == 0) {
//item左边分割线
left = 0;
right = left + ();
(left, top, right, bottom);
(c);
//item右边分割线
left = () + ;
right = left + ();
} else {
left = () + ;
right = left + ();
}
(left, top, right, bottom);
(c);
}
}
private boolean isLastColum(RecyclerView parent, int pos, int spanCount, int childCount) {
layoutManager = ();
if (layoutManager instanceof GridLayoutManager) {
// // 如果是最后一列，则不需要绘制右边
// if ((pos + 1) % spanCount == 0) {
// return true;
// }
} else if (layoutManager instanceof StaggeredGridLayoutManager) {
int orientation = ((StaggeredGridLayoutManager) layoutManager)
.getOrientation();
if (orientation == ) {
// 如果是最后一列，则不需要绘制右边
if ((pos + 1) % spanCount == 0) {
return true;
}
} else {
childCount = childCount - childCount % spanCount;
if (pos >= childCount)// 如果是最后一列，则不需要绘制右边
return true;
}
}
return false;
}
private boolean isLastRaw(RecyclerView parent, int pos, int spanCount, int childCount) {
layoutManager = ();
if (layoutManager instanceof GridLayoutManager) {
// childCount = childCount - childCount % spanCount;
// if (pos >= childCount)// 如果是最后一行，则不需要绘制底部
// return true;
} else if (layoutManager instanceof StaggeredGridLayoutManager) {
int orientation = ((StaggeredGridLayoutManager) layoutManager)
.getOrientation();
// StaggeredGridLayoutManager 且纵向滚动
if (orientation == ) {
childCount = childCount - childCount % spanCount;
if (pos >= childCount)// 如果是最后一行，则不需要绘制底部
return true;
// StaggeredGridLayoutManager 且横向滚动
} else {
// 如果是最后一行，则不需要绘制底部
if ((pos + 1) % spanCount == 0) {
return true;
}
}
}
return false;
}
@Override
public void getItemOffsets(Rect outRect, int itemPosition,
RecyclerView parent) {
int spanCount = getSpanCount(parent);
int childCount = ().getItemCount();
// 如果是最后一行，则不需要绘制底部
if (isLastRaw(parent, itemPosition, spanCount, childCount)) {
(0, 0, (), 0);
// 如果是最后一列，则不需要绘制右边
} else if (isLastColum(parent, itemPosition, spanCount, childCount)) {
(0, 0, 0, ());
} else {
(0, 0, (),
());
}
}
}