簡述
相信在開發(fā)的過程中，有不少人需要實(shí)現(xiàn)二級(jí)列表的需求，這次依然是站在大佬的肩膀上，給其他小伙伴們提供借鑒思路，老規(guī)矩先上圖。
視頻錄制效果圖.gif
參考的博客出處
RecyclerView 二級(jí)列表實(shí)現(xiàn)
RecyclerView實(shí)現(xiàn)側(cè)滑刪除
測滑菜單的實(shí)現(xiàn)
先來看看側(cè)滑的實(shí)現(xiàn)，這邊繼承了RecyclerView，直接在onInterceptTouchEvent方法中進(jìn)行觸摸判斷是否是滾動(dòng)或側(cè)滑
SlideRecyclerView自定義控件代碼如下：
public class SlideRecyclerView extends RecyclerView {
private static final String TAG = "SlideRecyclerView";
private static final int INVALID_POSITION = -1; // 觸摸到的點(diǎn)不在子View范圍內(nèi)
private static final int INVALID_CHILD_WIDTH = -1; // 子ItemView不含兩個(gè)子View
private static final int SNAP_VELOCITY = 600; // 最小滑動(dòng)速度
private VelocityTracker mVelocityTracker; // 速度追蹤器
private int mTouchSlop; // 認(rèn)為是滑動(dòng)的最小距離（一般由系統(tǒng)提供）
private Rect mTouchFrame; // 子View所在的矩形范圍
private Scroller mScroller;
private float mLastX; // 滑動(dòng)過程中記錄上次觸碰點(diǎn)X
private float mFirstX, mFirstY; // 首次觸碰范圍
private boolean mIsSlide; // 是否滑動(dòng)子View
private ViewGroup mFlingView; // 觸碰的子View
private int mPosition; // 觸碰的view的位置
private int mMenuViewWidth; // 菜單按鈕寬度
public SlideRecyclerView(Context context) {
this(context, null);
}
public SlideRecyclerView(Context context, @Nullable AttributeSet attrs) {
this(context, attrs, 0);
}
public SlideRecyclerView(Context context, @Nullable AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
mScroller = new Scroller(context);
}
@Override
public boolean onInterceptTouchEvent(MotionEvent e) {
int x = (int) e.getX();
int y = (int) e.getY();
obtainVelocity(e);
switch (e.getAction()) {
case MotionEvent.ACTION_DOWN:
if (!mScroller.isFinished()) { // 如果動(dòng)畫還沒停止，則立即終止動(dòng)畫
mScroller.abortAnimation();
}
mFirstX = mLastX = x;
mFirstY = y;
mPosition = pointToPosition(x, y); // 獲取觸碰點(diǎn)所在的position
if (mPosition != INVALID_POSITION) {
View view = mFlingView;
// 獲取觸碰點(diǎn)所在的view
mFlingView = (ViewGroup) getChildAt(mPosition - ((LinearLayoutManager) getLayoutManager()).findFirstVisibleItemPosition());
// 這里判斷一下如果之前觸碰的view已經(jīng)打開，而當(dāng)前碰到的view不是那個(gè)view則立即關(guān)閉之前的view，此處并不需要擔(dān)動(dòng)畫沒完成沖突，因?yàn)橹耙呀?jīng)abortAnimation
if (view != null && mFlingView != view && view.getScrollX() != 0) {
view.scrollTo(0, 0);
}
// 這里進(jìn)行了強(qiáng)制的要求，RecyclerView的子ViewGroup必須要有2個(gè)子view,這樣菜單按鈕才會(huì)有值，
// 需要注意的是:如果不定制RecyclerView的子View，則要求子View必須要有固定的width。
// 比如使用LinearLayout作為根布局，而content部分width已經(jīng)是match_parent，此時(shí)如果菜單view用的是wrap_content，menu的寬度就會(huì)為0。
if (mFlingView.getChildCount() == 2) {
mMenuViewWidth = mFlingView.getChildAt(1).getWidth();
} else {
mMenuViewWidth = INVALID_CHILD_WIDTH;
}
}
break;
case MotionEvent.ACTION_MOVE:
mVelocityTracker.computeCurrentVelocity(1000);
// 此處有倆判斷，滿足其一則認(rèn)為是側(cè)滑：
// 1.如果x方向速度大于y方向速度，且大于最小速度限制；
// 2.如果x方向的側(cè)滑距離大于y方向滑動(dòng)距離，且x方向達(dá)到最小滑動(dòng)距離；
float xVelocity = mVelocityTracker.getXVelocity();
float yVelocity = mVelocityTracker.getYVelocity();
if (Math.abs(xVelocity) > SNAP_VELOCITY && Math.abs(xVelocity) > Math.abs(yVelocity)
|| Math.abs(x - mFirstX) >= mTouchSlop
&& Math.abs(x - mFirstX) > Math.abs(y - mFirstY)) {
mIsSlide = true;
return true;
}
break;
case MotionEvent.ACTION_UP:
releaseVelocity();
break;
}
return super.onInterceptTouchEvent(e);
}
@Override
public boolean onTouchEvent(MotionEvent e) {
if (mIsSlide && mPosition != INVALID_POSITION) {
float x = e.getX();
obtainVelocity(e);
switch (e.getAction()) {
case MotionEvent.ACTION_DOWN: // 因?yàn)闆]有攔截，所以不會(huì)被調(diào)用到
break;
case MotionEvent.ACTION_MOVE:
// 隨手指滑動(dòng)
if (mMenuViewWidth != INVALID_CHILD_WIDTH) {
float dx = mLastX - x;
if (mFlingView.getScrollX() + dx <= mMenuViewWidth
&& mFlingView.getScrollX() + dx > 0) {
mFlingView.scrollBy((int) dx, 0);
}
mLastX = x;
}
break;
case MotionEvent.ACTION_UP:
if (mMenuViewWidth != INVALID_CHILD_WIDTH) {
int scrollX = mFlingView.getScrollX();
mVelocityTracker.computeCurrentVelocity(1000);
// 此處有兩個(gè)原因決定是否打開菜單：
// 1.菜單被拉出寬度大于菜單寬度一半；
// 2.橫向滑動(dòng)速度大于最小滑動(dòng)速度；
// 注意：之所以要小于負(fù)值，是因?yàn)橄蜃蠡瑒t速度為負(fù)值
if (mVelocityTracker.getXVelocity() < -SNAP_VELOCITY) { // 向左側(cè)滑達(dá)到側(cè)滑最低速度，則打開
mScroller.startScroll(scrollX, 0, mMenuViewWidth - scrollX, 0, Math.abs(mMenuViewWidth - scrollX));
} else if (mVelocityTracker.getXVelocity() >= SNAP_VELOCITY) { // 向右側(cè)滑達(dá)到側(cè)滑最低速度，則關(guān)閉
mScroller.startScroll(scrollX, 0, -scrollX, 0, Math.abs(scrollX));
} else if (scrollX >= mMenuViewWidth / 2) { // 如果超過刪除按鈕一半，則打開
mScroller.startScroll(scrollX, 0, mMenuViewWidth - scrollX, 0, Math.abs(mMenuViewWidth - scrollX));
} else { // 其他情況則關(guān)閉
mScroller.startScroll(scrollX, 0, -scrollX, 0, Math.abs(scrollX));
}
invalidate();
}
mMenuViewWidth = INVALID_CHILD_WIDTH;
mIsSlide = false;
mPosition = INVALID_POSITION;
releaseVelocity(); // 這里之所以會(huì)調(diào)用，是因?yàn)槿绻懊鏀r截了，就不會(huì)執(zhí)行ACTION_UP,需要在這里釋放追蹤
break;
}
return true;
} else {
// 此處防止RecyclerView正常滑動(dòng)時(shí)，還有菜單未關(guān)閉
closeMenu();
// Velocity，這里的釋放是防止RecyclerView正常攔截了，但是在onTouchEvent中卻沒有被釋放；
// 有三種情況：1.onInterceptTouchEvent并未攔截，在onInterceptTouchEvent方法中，DOWN和UP一對(duì)獲取和釋放；
// 2.onInterceptTouchEvent攔截，DOWN獲取，但事件不是被側(cè)滑處理，需要在這里進(jìn)行釋放；
// 3.onInterceptTouchEvent攔截，DOWN獲取，事件被側(cè)滑處理，則在onTouchEvent的UP中釋放。
releaseVelocity();
}
return super.onTouchEvent(e);
}
private void releaseVelocity() {
if (mVelocityTracker != null) {
mVelocityTracker.clear();
mVelocityTracker.recycle();
mVelocityTracker = null;
}
}
private void obtainVelocity(MotionEvent event) {
if (mVelocityTracker == null) {
mVelocityTracker = VelocityTracker.obtain();
}
mVelocityTracker.addMovement(event);
}
public int pointToPosition(int x, int y) {
int firstPosition = ((LinearLayoutManager) getLayoutManager()).findFirstVisibleItemPosition();
Rect frame = mTouchFrame;
if (frame == null) {
mTouchFrame = new Rect();
frame = mTouchFrame;
}
final int count = getChildCount();
for (int i = count - 1; i >= 0; i--) {
final View child = getChildAt(i);
if (child.getVisibility() == View.VISIBLE) {
child.getHitRect(frame);
if (frame.contains(x, y)) {
return firstPosition + i;
}
}
}
return INVALID_POSITION;
}
@Override
public void computeScroll() {
if (mScroller.computeScrollOffset()) {
mFlingView.scrollTo(mScroller.getCurrX(), mScroller.getCurrY());
invalidate();
}
}
/**
* 將顯示子菜單的子view關(guān)閉
* 這里本身是要自己來實(shí)現(xiàn)的，但是由于不定制item，因此不好監(jiān)聽器點(diǎn)擊事件，因此需要調(diào)用者手動(dòng)的關(guān)閉
*/
public void closeMenu() {
if (mFlingView != null && mFlingView.getScrollX() != 0) {
mFlingView.scrollTo(0, 0);
}
}
}
關(guān)于側(cè)滑item的添加，則在適配器的編寫中，設(shè)置在每個(gè)item的布局上，注意這里的側(cè)滑菜單按鈕的寬度不能設(shè)置為wrap_content，不然側(cè)滑按鈕的寬度就會(huì)為0,需要給固定寬度，這里先給上布局截圖
item布局.png
為了看看效果，這邊寫了個(gè)簡單的適配器，實(shí)現(xiàn)item中兩個(gè)控件的點(diǎn)擊監(jiān)聽，側(cè)滑出刪除菜單后點(diǎn)擊刪除數(shù)據(jù)并且提示并關(guān)閉，適配器代碼如下：
public class TestAdapter extends RecyclerView.Adapter<TestAdapter.ViewHolder> {
private List<String> list;
private onAdapterItemClickListener itemClickListener;
public TestAdapter(List<String> list) {
this.list = list;
}
@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view= LayoutInflater.from(parent.getContext()).
inflate(R.layout.item_text,parent,false);
return new ViewHolder(view);
}
@Override
public void onBindViewHolder(@NonNull ViewHolder holder, final int position) {
holder.tv_content.setText(list.get(position));
holder.tv_content.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
itemClickListener.onItemClick(view,position);
}
});
holder.tv_delete.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
itemClickListener.onItemClick(view,position);
}
});
}
@Override
public int getItemCount() {
return list.size();
}
static class ViewHolder extends RecyclerView.ViewHolder{
TextView tv_content,tv_delete;
public ViewHolder(@NonNull View itemView) {
super(itemView);
tv_content=itemView.findViewById(R.id.tv_content);
tv_delete=itemView.findViewById(R.id.tv_delete);
}
}
public void reFreshData(List<String> list){
this.list=list;
notifyDataSetChanged();
}
public interface onAdapterItemClickListener{
void onItemClick(View view,int selectPosition);
}
public void setItemClickListener(onAdapterItemClickListener itemClickListener) {
this.itemClickListener = itemClickListener;
}
}
在主界面綁定控件后實(shí)現(xiàn)適配器初始化，initAdapter()代碼如下：
private void initAdapter() {
final List<String> data=new ArrayList<>();
for(int i=0; i<10;i++){
data.add("i:"+i);
}
final TestAdapter testAdapter=new TestAdapter(data);
ry.setLayoutManager(new LinearLayoutManager(this));
ry.setAdapter(testAdapter);
testAdapter.setItemClickListener(new TestAdapter.onAdapterItemClickListener() {
@Override
public void onItemClick(View view, int selectPosition) {
switch (view.getId()){
case R.id.tv_content:
Toast.makeText(MainActivity.this, "點(diǎn)擊了：" + data.get(selectPosition), Toast.LENGTH_SHORT).show();
break;
case R.id.tv_delete:
ry.closeMenu();
Toast.makeText(MainActivity.this, "刪除第：" +(selectPosition+1) +"個(gè)", Toast.LENGTH_SHORT).show();
data.remove(selectPosition);
testAdapter.reFreshData(data);
break;
}
}
});
}
效果圖如下：
測滑簡單效果圖.gif
到這里為止實(shí)現(xiàn)了簡單側(cè)滑，若是覺得可擴(kuò)展功能太少，github上有更為成熟的自定義控件，各位可以看看這位大佬的開源庫： com.yanzhenjie.recyclerview
二級(jí)列表適配器的實(shí)現(xiàn)
接著來說說二級(jí)列表的實(shí)現(xiàn)，其實(shí)就是實(shí)現(xiàn)多樣式布局的編寫，根據(jù)item類型來綁定我們自定義創(chuàng)建的holder,然后在各自的item實(shí)現(xiàn)控件不同樣式布局編寫,這里我在原來大佬的基礎(chǔ)上實(shí)現(xiàn)打開某個(gè)父列表下的子item。
先編寫用來封裝數(shù)據(jù)類型的類DataTree
import java.util.List;
/**
* 二級(jí)列表數(shù)據(jù)格式
*/
public class DataTree<K, V> {
private K groupItem;//第一級(jí)
private List<V> subItems;//第二級(jí)
public DataTree(K groupItem, List<V> subItems) {
this.groupItem = groupItem;
this.subItems = subItems;
}
public K getGroupItem() {
return groupItem;
}
public void setGroupItem(K groupItem) {
this.groupItem = groupItem;
}
public List<V> getSubItems() {
return subItems;
}
public void setSubItems(List<V> subItems) {
this.subItems = subItems;
}
}
接著再編寫用于判斷每個(gè)item的視圖類型，用來區(qū)分ViewType 的類型與記錄索引位置的類 ItemStatus
public class ItemStatus {
public static final int VIEW_TYPE_GROUPITEM = 0;
public static final int VIEW_TYPE_SUBITEM = 1;
private int viewType;
private int groupItemIndex = 0;
private int subItemIndex = -1;
public ItemStatus() {
}
public int getViewType() {
return viewType;
}
public void setViewType(int viewType) {
this.viewType = viewType;
}
public int getGroupItemIndex() {
return groupItemIndex;
}
public void setGroupItemIndex(int groupItemIndex) {
this.groupItemIndex = groupItemIndex;
}
public int getSubItemIndex() {
return subItemIndex;
}
public void setSubItemIndex(int subItemIndex) {
this.subItemIndex = subItemIndex;
}
}
接著來實(shí)現(xiàn)我們的抽象類SecondListAdapter
public abstract class SecondListAdapter<GVH, SVH extends RecyclerView.ViewHolder> extends RecyclerView
.Adapter<RecyclerView.ViewHolder> {
private List<Boolean> groupItemStatus = new ArrayList<>();
private List<DataTree> dataTrees = new ArrayList<>();
/**
* 用來通知刷新某個(gè)父view是否展開其子列表
*/
public void openParentItem(int index) {
expandOneItem(index);
}
private void expandOneItem(int index) {
if (index > dataTrees.size() - 1) return;//超過下標(biāo)默認(rèn)不打
groupItemStatus.clear();
for (int i = 0; i < dataTrees.size(); i++) {
if (index == i) {
groupItemStatus.add(true);
} else {
groupItemStatus.add(false);
}
}
}
/**
* 用于刷新數(shù)據(jù)
*/
public void notifyNewData(List dataTrees) {
setDataTrees(dataTrees);
}
private void setDataTrees(List dataTrees) {
this.dataTrees = dataTrees;
initGroupItemStatus(groupItemStatus);
notifyDataSetChanged();
}
/**
* 刷新數(shù)據(jù)，初始化 ，將所有列表的狀態(tài)都重置為False,不展開列表
*/
private void initGroupItemStatus(List<Boolean> groupItemStatus) {
for (int i = 0; i < dataTrees.size(); i++) {
groupItemStatus.add(false);
}
}
/**
* 二級(jí)列表的父holder
*/
public abstract RecyclerView.ViewHolder groupItemViewHolder(ViewGroup parent);
/**
* 二級(jí)列表的子holder
*/
public abstract RecyclerView.ViewHolder subItemViewHolder(ViewGroup viewGroup);
/**
* 根據(jù)viewType 選擇實(shí)現(xiàn)不同的項(xiàng)目布局
*/
@Override
public final RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
RecyclerView.ViewHolder viewHolder = null;
if (viewType == ItemStatus.VIEW_TYPE_GROUPITEM) {
viewHolder = groupItemViewHolder(parent);
} else if (viewType == ItemStatus.VIEW_TYPE_SUBITEM) {
viewHolder = subItemViewHolder(parent);
}
return viewHolder;
}
/**
* 抽象方法 設(shè)置綁定父類Holder 與獲取其下標(biāo)位置
*/
public abstract void onGroupItemBindViewHolder(RecyclerView.ViewHolder holder, int
groupItemIndex, boolean ifExpand);
/**
* 抽象方法 設(shè)置綁定子類Holder 與獲取其下標(biāo)位置
*/
public abstract void onSubItemBindViewHolder(RecyclerView.ViewHolder holder, int
groupItemIndex, int subItemIndex);
/**
* 抽象方法 實(shí)現(xiàn)二級(jí)列表父item是否點(diǎn)擊
*/
public abstract void onGroupItemClick(Boolean isExpand, GVH holder, int groupItemIndex);
/**
* 抽象方法 實(shí)現(xiàn)二級(jí)列表子item的點(diǎn)擊
*/
public abstract void onSubItemClick(SVH holder, int groupItemIndex, int subItemIndex);
@Override
public void onBindViewHolder(final RecyclerView.ViewHolder holder, int position) {
final ItemStatus itemStatus = getItemStatusByPosition(position);
final DataTree dt = dataTrees.get(itemStatus.getGroupItemIndex());
if (itemStatus.getViewType() == ItemStatus.VIEW_TYPE_GROUPITEM) {
final int groupItemIndex = itemStatus.getGroupItemIndex();
onGroupItemBindViewHolder(holder, itemStatus.getGroupItemIndex(), groupItemStatus.get(groupItemIndex));
holder.itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (!groupItemStatus.get(groupItemIndex)) {
onGroupItemClick(false, (GVH) holder, groupItemIndex);
groupItemStatus.set(groupItemIndex, true);
notifyItemRangeInserted(holder.getAdapterPosition() + 1, dt.getSubItems
().size());
} else {
onGroupItemClick(true, (GVH) holder, groupItemIndex);
groupItemStatus.set(groupItemIndex, false);
notifyItemRangeRemoved(holder.getAdapterPosition() + 1, dt.getSubItems
().size());
}
}
});
} else if (itemStatus.getViewType() == ItemStatus.VIEW_TYPE_SUBITEM) {
onSubItemBindViewHolder(holder, itemStatus.getGroupItemIndex(), itemStatus
.getSubItemIndex());
holder.itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
onSubItemClick((SVH) holder, itemStatus.getGroupItemIndex(), itemStatus.getSubItemIndex());
}
});
}
}
/**
* 每行該顯示哪種item
*/
@Override
public int getItemViewType(int position) {
return getItemStatusByPosition(position).getViewType();
}
/***
* 統(tǒng)計(jì)所有的item數(shù)量
* */
@Override
public final int getItemCount() {
int itemCount = 0;
if (groupItemStatus.size() == 0) {
return 0;
}
for (int i = 0; i < dataTrees.size(); i++) {
if (groupItemStatus.get(i)) {
itemCount += dataTrees.get(i).getSubItems().size() + 1;
} else {
itemCount++;
}
}
return itemCount;
}
/**
* 根據(jù)當(dāng)前索引 判斷是一級(jí)還是二級(jí)的item
*/
private ItemStatus getItemStatusByPosition(int position) {
ItemStatus itemStatus = new ItemStatus();
int count = 0;
int i = 0;
for (i = 0; i < groupItemStatus.size(); i++) {
if (count == position) {
itemStatus.setViewType(ItemStatus.VIEW_TYPE_GROUPITEM);
itemStatus.setGroupItemIndex(i);
break;
} else if (count > position) {
itemStatus.setViewType(ItemStatus.VIEW_TYPE_SUBITEM);
itemStatus.setGroupItemIndex(i - 1);
itemStatus.setSubItemIndex(position - (count - dataTrees.get(i - 1).getSubItems
().size()));
break;
}
count++;
if (groupItemStatus.get(i)) {
count += dataTrees.get(i).getSubItems().size();
}
}
if (i >= groupItemStatus.size()) {
itemStatus.setGroupItemIndex(i - 1);
itemStatus.setViewType(ItemStatus.VIEW_TYPE_SUBITEM);
itemStatus.setSubItemIndex(position - (count - dataTrees.get(i - 1).getSubItems().size
()));
}
return itemStatus;
}
}
讓我們自己創(chuàng)建的適配器RecyclerAdapter 繼承抽象類 SecondListAdapter，實(shí)現(xiàn)其中的方法
public class RecyclerAdapter extends SecondListAdapter<RecyclerAdapter.GroupItemViewHolder, RecyclerAdapter.SubItemViewHolder> {
private Context context;
private List<DataTree<String, String>> dts;
private OnParentItemClickListener parentItemClickListener;
private OnSubItemClickListener subItemClickListener;
private int expandIndex = -1;//打開某個(gè)父級(jí)item的子列表的下標(biāo)，默認(rèn)不打開
public RecyclerAdapter(Context context, OnParentItemClickListener parentItemClickListener, OnSubItemClickListener subItemClickListener) {
this.context = context;
this.parentItemClickListener = parentItemClickListener;
this.subItemClickListener = subItemClickListener;
}
@Override
public RecyclerView.ViewHolder groupItemViewHolder(ViewGroup parent) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_first_level, parent, false);
return new GroupItemViewHolder(view);
}
@Override
public RecyclerView.ViewHolder subItemViewHolder(ViewGroup viewGroup) {
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.item_second_level, viewGroup, false);
return new SubItemViewHolder(view);
}
@Override
public void onGroupItemBindViewHolder(RecyclerView.ViewHolder holder, final int groupItemIndex, boolean ifExpand) {
((GroupItemViewHolder) holder).tv_group.setText("第" + (groupItemIndex + 1) + "個(gè)" + dts.get(groupItemIndex).getGroupItem());
((GroupItemViewHolder) holder).tv_delete.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
parentItemClickListener.onParentClick(v, groupItemIndex);
}
});
if (groupItemIndex == expandIndex)
((GroupItemViewHolder) holder).img_right.setRotation(ifExpand ? 90 : 0);
}
@Override
public void onSubItemBindViewHolder(RecyclerView.ViewHolder holder, int groupItemIndex, int subItemIndex) {
((SubItemViewHolder) holder).tv_name.setText(dts.get(groupItemIndex).getSubItems().get(subItemIndex));
}
@Override
public void onGroupItemClick(Boolean isExpand, GroupItemViewHolder holder, int groupItemIndex) {
//isExpand:false 展開 true：收起來
holder.img_right.setRotation(isExpand ? 0 : 90);
}
@Override
public void onSubItemClick(SubItemViewHolder holder, int groupItemIndex, int subItemIndex) {
subItemClickListener.onChildClick(groupItemIndex, subItemIndex);
}
public static class GroupItemViewHolder extends RecyclerView.ViewHolder {
TextView tv_group, tv_delete;
ImageView img_right;
LinearLayout ly_parent;
public GroupItemViewHolder(View itemView) {
super(itemView);
tv_group = itemView.findViewById(R.id.tv_group);
img_right = itemView.findViewById(R.id.img_right);
tv_delete = itemView.findViewById(R.id.tv_delete);
ly_parent = itemView.findViewById(R.id.ly_parent);
}
}
public static class SubItemViewHolder extends RecyclerView.ViewHolder {
TextView tv_name;
public SubItemViewHolder(View itemView) {
super(itemView);
tv_name = itemView.findViewById(R.id.tv_name);
}
}
public void setData(List data) {
dts = data;
notifyNewData(dts);
}
public void expand(int position) {
expandIndex = position;
openParentItem(position);
notifyNewData(dts);
}
/**
* 父列表控件點(diǎn)擊監(jiān)聽
*/
public interface OnParentItemClickListener {
void onParentClick(View view, int groupItemIndex);
}
/**
* 二級(jí)列表整個(gè)item點(diǎn)擊監(jiān)聽
*/
public interface OnSubItemClickListener {
void onChildClick(int groupItemIndex, int subItemIndex);
}
}
這里附上我兩個(gè)不同的holder的布局編寫樣式
item_first_level.png
item_second_level.png
接下來在在主界面實(shí)現(xiàn)數(shù)據(jù)填充和初始化，綁定控件啥的就不寫，直接上適配器初始化的代碼 initAdapter()：
private void initAdapter() {
List<String> professionList1 = new ArrayList<>();
professionList1.add("Android 開發(fā)工程師");
professionList1.add("后臺(tái)開發(fā)");
List<String> professionList2 = new ArrayList<>();
professionList2.add("WEB前端工程師");
dataTrees.add(new DataTree<String, String>("JAVA", professionList1));
dataTrees.add(new DataTree<>("JavaScript", professionList2));
//二級(jí)列表初始化
adapter = new RecyclerAdapter(this, this, this);
ry.setLayoutManager(new LinearLayoutManager(this));
ry.setAdapter(adapter);
adapter.setData(dataTrees);
//這個(gè)是實(shí)現(xiàn)填充數(shù)據(jù)后，默認(rèn)展開某個(gè)父級(jí)列表下的子item
// 傳入的下標(biāo)超過數(shù)據(jù)集合的索引則默認(rèn)不打開，可不調(diào)用該方法
adapter.expand(0);
}
這個(gè)運(yùn)行的效果就是最先貼出來的gif圖（ adapter.expand(0) 沒有錄制進(jìn)去，就是進(jìn)入的時(shí)候默認(rèn)打開了某個(gè)父級(jí)列表下的子列表 ，小伙伴們好奇的話可自行去試試)
至此，二級(jí)列表的實(shí)現(xiàn)到此為止，在這里在附上我項(xiàng)目的源碼，有不足之處麻煩指正，希望能幫上閱讀此篇文章的各位
