RecyclerView 实现网格布局 item四周有分割线 展示分类信息
效果如下:
每一个item核心代码:
public class HistoryItemView extends LinearLayout {
private ScrollViewWithRecyclerView historyRv;
private Context context;
private List data;
private String title;
private RecyclerView.Adapter adapter;
private TextView brandTv;
private TextView collapseTv;
private HistoryData historyData;
public HistoryItemView(Context context) {
this(context, null);
}
public HistoryItemView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public HistoryItemView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
this.context = context;
initView();
}
private void initView() {
setOrientation(VERTICAL);
View view = inflate(getContext(), R.layout.layout_item_history, this);
brandTv = (TextView)view.findViewById(R.id.brand);
collapseTv = (TextView)view.findViewById(R.id.collapse);
historyRv = view.findViewById(R.id.historyRv);
initAdapter();
GridLayoutManager gridLayoutManager = new GridLayoutManager(context, 3);
historyRv.setLayoutManager(gridLayoutManager);
GridItemDivider gridLayoutDivider = new GridItemDivider( 2, Color.parseColor("#CCCCCC"));
historyRv.addItemDecoration(gridLayoutDivider);
historyRv.setAdapter(adapter);
collapseTv.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
boolean isOpen = historyData.isOpen();
String text = isOpen ? "展开" : "收起";
collapseTv.setText(text);
historyData.setOpen(!isOpen);
adapter.notifyDataSetChanged();
}
});
}
private void initAdapter() {
final LayoutInflater mInflater = LayoutInflater.from(context);
adapter = new RecyclerView.Adapter() {
@NonNull
@Override
public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int i) {
View itemView = mInflater.inflate(R.layout.table_row_item, parent, false);
return new HistoryViewHolder(itemView);
}
@Override
public void onBindViewHolder(@NonNull RecyclerView.ViewHolder viewHolder, int i) {
HistoryViewHolder holder = (HistoryViewHolder) viewHolder;
holder.bindData(i);
}
@Override
public int getItemCount() {
if( data.size() >= 6 && !historyData.isOpen()){
return 6;
}
return data.size();
}
};
}
public void bindData(HistoryData historyData) {
this.historyData = historyData;
data = historyData.getContentList();
title = historyData.getTitile();
brandTv.setText(title);
adapter.notifyDataSetChanged();
}
private class HistoryViewHolder extends RecyclerView.ViewHolder {
TextView historyTv;
public HistoryViewHolder(View itemView) {
super(itemView);
historyTv = itemView.findViewById(R.id.history);
}
public void bindData(int pos) {
String content = data.get(pos);
historyTv.setText(content);
}
}
} 布局文件:
每一个item的分割线:
public class GridItemDivider extends RecyclerView.ItemDecoration {
private String TAG = getClass().getSimpleName();
private static final int[] ATTRS = new int[]{android.R.attr.listDivider};
private Drawable divider;
public GridItemDivider(Context context) {
final TypedArray a = context.obtainStyledAttributes(ATTRS);
divider = a.getDrawable(0);
a.recycle();
}
public GridItemDivider(Drawable drawable) {
divider = drawable;
}
public GridItemDivider(int height, int color) {
GradientDrawable shapeDrawable = new GradientDrawable();
shapeDrawable.setColor(color);
shapeDrawable.setShape(GradientDrawable.RECTANGLE);
shapeDrawable.setSize(height, height);
divider = shapeDrawable;
}
@Override
public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
drawHorizontal(c, parent);
drawVertical(c, parent);
}
private int getSpanCount(RecyclerView parent) {
// 列数
int spanCount = -1;
RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
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 = parent.getChildCount(); //获取可见item的数量
int spanCount = getSpanCount(parent);
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.getLeft() - params.leftMargin;
final int right = child.getRight() + params.rightMargin
+ divider.getIntrinsicWidth();
final int top = child.getBottom() + params.bottomMargin;
final int bottom = top + divider.getIntrinsicHeight();
divider.setBounds(left, top, right, bottom);
divider.draw(c);
if (i < spanCount) { //画第一行顶部的分割线
drawHorizontalForFirstRow(c, child);
}
}
}
private void drawHorizontalForFirstRow(Canvas c, View child) {
final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
.getLayoutParams();
int left = child.getLeft() - params.leftMargin - divider.getIntrinsicWidth();
int top = child.getTop() - params.topMargin - divider.getIntrinsicHeight();
int right = child.getRight() + params.rightMargin + divider.getIntrinsicWidth();
int bottom = top + divider.getIntrinsicHeight();
divider.setBounds(left, top, right, bottom);
divider.draw(c);
}
private void drawVerticalForFirstColum(Canvas c, View child) {
final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
.getLayoutParams();
int left = child.getLeft() - params.leftMargin - divider.getIntrinsicWidth();
int top = child.getTop() - params.topMargin;
int right = child.getLeft() - params.leftMargin;
int bottom = top + child.getHeight() + divider.getIntrinsicHeight();
divider.setBounds(left, top, right, bottom);
divider.draw(c);
}
public void drawVertical(Canvas c, RecyclerView parent) {
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.getTop() - params.topMargin;
final int bottom = child.getBottom() + params.bottomMargin;
final int left = child.getRight() + params.rightMargin;
final int right = left + divider.getIntrinsicWidth();
divider.setBounds(left, top, right, bottom);
divider.draw(c);
if (isFirstColum(parent, i, getSpanCount(parent))) { //画第一列左边分割线
drawVerticalForFirstColum(c, child);
}
}
}
private boolean isLastColum(RecyclerView parent, int pos, int spanCount,
int childCount) {
RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
if (layoutManager instanceof GridLayoutManager) {
if ((pos + 1) % spanCount == 0)// 如果是最后一列，则不需要绘制右边
{
return true;
}
} else if (layoutManager instanceof StaggeredGridLayoutManager) {
int orientation = ((StaggeredGridLayoutManager) layoutManager)
.getOrientation();
if (orientation == StaggeredGridLayoutManager.VERTICAL) {
if ((pos + 1) % spanCount == 0)// 如果是最后一列，则不需要绘制右边
{
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) {
RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
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();
if (orientation == StaggeredGridLayoutManager.VERTICAL) {
childCount = childCount - childCount % spanCount;
// 如果是最后一行，则不需要绘制底部
if (pos >= childCount)
return true;
} 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;
}
//是否为第一列
private boolean isFirstColum(RecyclerView parent, int pos, int spanCount) {
RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
if (layoutManager instanceof GridLayoutManager) { //网格布局
if ((pos + 1) % spanCount == 1) {
return true;
}
}
return false;
}
//是否为第一行
private boolean isFirstRaw(int pos, int spanCount) {
if (pos < spanCount) {
return true;
}
return false;
}
@Override
public void getItemOffsets(Rect outRect, int itemPosition,
RecyclerView parent) {
int spanCount = getSpanCount(parent); //列数
if (itemPosition == 0) { //第一行第一个，四边都画
outRect.set(divider.getIntrinsicWidth(), divider.getIntrinsicHeight(),
divider.getIntrinsicWidth(), divider.getIntrinsicHeight());
} else if (isFirstRaw(itemPosition, spanCount)) { //第一行，画上下右三边
outRect.set(0, divider.getIntrinsicHeight(), divider.getIntrinsicWidth(), divider.getIntrinsicHeight());
} else if (isFirstColum(parent, itemPosition, spanCount)) { //第一列，画左右下三边
outRect.set(divider.getIntrinsicWidth(), 0, divider.getIntrinsicWidth(), divider.getIntrinsicHeight());
} else { //其他，画右下两边
outRect.set(0, 0, divider.getIntrinsicWidth(), divider.getIntrinsicHeight());
}
}
}
demo下载地址