这段时间在做一个app，整体功能不是非常复杂，所以感觉一直在啃老本，直到碰到一个需求，要实现列表拖拽功能，经过一番绞尽脑汁的探索加上参考各路大神的博客终于做完了，在此和大家分享自己的经历
我最开始想到的方案是用第三方库，所以借助万能的百度查到了一个DragsortListview，然后就添加进项目中开始写Demo，结果发现各种坑爹（这都啥玩意儿，还有这么多人给星），然后我冷静地想了一下开始学Android的时候正是RecyclerView大火各方大神写动效，什么瀑布流，网格好像就有这个拖动效果，百度一查，谷歌爸爸早就把拖动的接口预留在RecyclerView里面了（掀桌子）
RecyclerView是ViewGroup的子类，没有像ListView那样OnItemClickListener接口，点击事件需要自己实现和传值
ItemTouchHelper是ItemDecoration的子类，用于定制RecyclerView的动效，ItemDecoration用于设置列表条目的分割线，ItemTouchHelper.Callback是联系RecyclerView.Adapter和ItemTouchHelper的关键，在其中可以设置侧滑和拖动等多种手势
注意ReportListActivity中有两个监听接口，一个是View.OnClickListener，另外一个是RecyclerAdapter.Callback，为了区分开来，前者我用接口实现，后者用内部类实现
我已经把这个模块放到GitHub上开源了，有兴趣可以看一下
https://github.com/caoguoly940713/UIFrame
废话不多说，直接上主菜
主窗口代码：
/**
* 编辑状态下长按拖动条目
* 1.通过ItemTouchHelper.Callback实现长按拖动
* 2.通过isEditable的值判断是否编辑状态，初值是false
* 3.切换编辑状态要把isEditable的值取反，并改变复选框图标状态
* 4.在编辑状态下，按返回键回到非编辑状态
* 5.RecyclerView的点击事件通过RecyclerAdapter.Callback实现
*/
public class ReportListActivity extends AppCompatActivity implements View.OnClickListener {
private static final String TAG = "ReportListActivity";
@BindView(R.id.tv_title_middle)
TextView title;
@BindView(R.id.title_left)
ImageView backButton;
@BindView(R.id.online_report_listview)
RecyclerView mRecyclerView;
@BindView(R.id.edit_tv)
TextView edit;
@BindView(R.id.filter_tv)
TextView filter;
@BindView(R.id.btn_delete)
TextView delete;
@BindView(R.id.btn_release)
TextView release;
@BindView(R.id.btn_close)
TextView close;
@BindView(R.id.btn_top)
TextView top;
private Context mContext;
private boolean isEditable;
private RecyclerAdapter mAdapter;
private List mClsOnlineReportList;
private ItemTouchHelper itemTouchHelper;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_online_report);
ButterKnife.bind(this);
initView();
initData();
initListener();
}
private void initData() {
mContext = this;
getOfflineData(20);
setIsEditable(false);
OnlineReportListCallback callback = new OnlineReportListCallback(mAdapter);
itemTouchHelper = new ItemTouchHelper(callback);
setRecyclerViewDraggable(false);
}
private void getOfflineData(int num) {
List clsOnlineReportList = new ArrayList<>();
for (int i = 0; i < num; i++) {
ClsOnlineReport onlineReport = new ClsOnlineReport();
onlineReport.setActiveDate("activeDate " + i);
onlineReport.setAutoCloseDate("autoCloseDate " + i);
onlineReport.setBulletinID("bulletinID " + i);
onlineReport.setBulletinTime("bulletinTime " + i);
onlineReport.setBulletinTitle("bulletinTitle " + i);
onlineReport.setCreater("creater " + i);
onlineReport.setCreaterID("creater " + i);
onlineReport.setIsActive("isActive " + i);
onlineReport.setModiManID("modiManID " + i);
onlineReport.setModiManName("modiManName " + i);
onlineReport.setOnTop("onTop " + i);
onlineReport.setOrderNum("oderNum " + i);
clsOnlineReportList.add(onlineReport);
}
mClsOnlineReportList = clsOnlineReportList;
mAdapter = new RecyclerAdapter(mClsOnlineReportList);
mRecyclerView.setAdapter(mAdapter);
}
private void initView() {
title.setText("可拖拽列表");
edit.setVisibility(View.VISIBLE);
hideBottomMenu();
mRecyclerView.setLayoutManager(new LinearLayoutManager(mContext));
}
private void initListener() {
filter.setOnClickListener(this);
backButton.setOnClickListener(this);
edit.setOnClickListener(this);
delete.setOnClickListener(this);
release.setOnClickListener(this);
close.setOnClickListener(this);
top.setOnClickListener(this);
mAdapter.setmCallback((v, position) -> {
switch (v.getId()) {
case R.id.view_parent_1:
case R.id.view_parent_2:
ClsOnlineReport clsOnlineReport = mClsOnlineReportList.get(position);
if (getIsEditable()) {
if (clsOnlineReport.getIsCheckBoxVisible()) {
clsOnlineReport.setIsChecked(!clsOnlineReport.getIsChecked());
mAdapter.notifyDataSetChanged();
}
for (int i = 0; i < mClsOnlineReportList.size(); i++) {
ClsOnlineReport onlineReport = mClsOnlineReportList.get(i);
if (onlineReport.getIsChecked()) {
showBottomMenu();
break;
}
if (i == mClsOnlineReportList.size() - 1) {
hideBottomMenu();
}
}
} else {
Intent intent = new Intent(mContext, ReportDetailActivity.class);
intent.putExtra("bulletinID", clsOnlineReport.getBulletinID());
startActivityForResult(intent, 16371);
}
}
});
}
@Override
public void onBackPressed() {
if (getIsEditable()) {
switchEditable();
} else {
finish();
}
}
@Override
public void onClick(View v) {
if (v.getId() == R.id.title_left) {
if (getIsEditable()) {
switchEditable();
} else {
finish();
}
}
if (v.getId() == R.id.edit_tv) {
switchEditable();
}
switch (v.getId()) {
case R.id.btn_top:
case R.id.btn_close:
case R.id.btn_release:
case R.id.btn_delete:
Toast.makeText(mContext, "在此处调用接口", Toast.LENGTH_SHORT).show();
}
}
private void hideBottomMenu() {
delete.setVisibility(View.GONE);
top.setVisibility(View.GONE);
release.setVisibility(View.GONE);
close.setVisibility(View.GONE);
}
private void showBottomMenu() {
delete.setVisibility(View.VISIBLE);
top.setVisibility(View.VISIBLE);
release.setVisibility(View.VISIBLE);
close.setVisibility(View.VISIBLE);
}
private void switchEditable() {
setIsEditable(!getIsEditable());
for (ClsOnlineReport clsOnlineReport : mClsOnlineReportList) {
clsOnlineReport.setIsCheckBoxVisible(getIsEditable());
clsOnlineReport.setIsChecked(false);
}
mAdapter.notifyDataSetChanged();
hideBottomMenu();
setRecyclerViewDraggable(getIsEditable());
}
public boolean getIsEditable() {
return isEditable;
}
public void setIsEditable(boolean isEditable) {
this.isEditable = isEditable;
}
private void setRecyclerViewDraggable(boolean draggable) {
if (draggable) {
itemTouchHelper.attachToRecyclerView(mRecyclerView);
} else {
itemTouchHelper.attachToRecyclerView(null);
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
if (requestCode == 16371 && resultCode == RESULT_OK) {
refreshData();
}
super.onActivityResult(requestCode, resultCode, data);
}
private void refreshData() {
Toast.makeText(mContext, "在此处调用接口", Toast.LENGTH_SHORT).show();
}
}
布局文件代码：
适配器代码：
/**
* 可拖拽列表的适配器，
* 1.需要实现OnlineReportListCallback.ItemTouchMoveListener
* 2.持有一个接口用于传递position
*/
public class RecyclerAdapter extends RecyclerView.Adapter implements OnlineReportListCallback.ItemTouchMoveListener, View.OnClickListener {
private List mList;
private Callback mCallback;
public RecyclerAdapter(List mList) {
this.mList = mList;
}
public void setmCallback(Callback mCallback) {
this.mCallback = mCallback;
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
View v = inflater.inflate(R.layout.item_report_list, parent, false);
return new ItemHolder(v);
}
@Override
public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
ClsOnlineReport clsOnlineReport = mList.get(position);
ItemHolder itemHolder = (ItemHolder) holder;
if (clsOnlineReport.getIsCheckBoxVisible()) {
itemHolder.checkbox.setVisibility(View.VISIBLE);
itemHolder.drag.setVisibility(View.VISIBLE);
} else {
itemHolder.checkbox.setVisibility(View.GONE);
itemHolder.drag.setVisibility(View.GONE);
}
if (clsOnlineReport.getIsChecked()) {
itemHolder.checkbox.setImageResource(R.drawable.ic_check_box_black_24dp);
} else {
itemHolder.checkbox.setImageResource(R.drawable.ic_check_box_outline_blank_black_24dp);
}
itemHolder.parent1.setTag(position);
itemHolder.parent2.setTag(position);
itemHolder.parent1.setOnClickListener(this);
itemHolder.parent2.setOnClickListener(this);
itemHolder.time.setText(clsOnlineReport.getBulletinTime());
itemHolder.title.setText(clsOnlineReport.getBulletinTitle());
itemHolder.author.setText(clsOnlineReport.getCreater());
}
@Override
public int getItemCount() {
return mList.size();
}
@Override
public boolean onItemMove(int fromPosition, int toPosition) {
Collections.swap(mList, fromPosition, toPosition);
notifyItemMoved(fromPosition, toPosition);
return true;
}
class ItemHolder extends RecyclerView.ViewHolder {
@BindView(R.id.online_report_time)
TextView time;
@BindView(R.id.online_report_title)
TextView title;
@BindView(R.id.online_report_author)
TextView author;
@BindView(R.id.online_report_drag)
ImageView drag;
@BindView(R.id.online_report_checkbox)
ImageView checkbox;
@BindView(R.id.view_parent_1)
LinearLayout parent1;
@BindView(R.id.view_parent_2)
LinearLayout parent2;
ItemHolder(View itemView) {
super(itemView);
ButterKnife.bind(this, itemView);
}
}
@Override
public void onClick(View v) {
mCallback.onClick(v, (int) v.getTag());
}
public interface Callback {
void onClick(View v, int position);
}
}
回调接口代码：
/**
* 用来完成RecyclerView长按拖拽的关键接口
* 1.getMovementFlags里面表示设置为上下拖动
* 2.onSelectedChanged里面表示拖动状态下改变背景色，拖动完成后恢复背景色
* 3.拖动完成的时候viewHolder的值为空！！！所以要用srcHolder
*/
public class OnlineReportListCallback extends ItemTouchHelper.Callback {
private ColorDrawable drawable;
private RecyclerView.ViewHolder srcHolder;
public interface ItemTouchMoveListener {
boolean onItemMove(int fromPosition, int toPosition);
}
private ItemTouchMoveListener moveListener;
public OnlineReportListCallback(ItemTouchMoveListener moveListener) {
this.moveListener = moveListener;
int rgb = Color.rgb(0xff, 0xff, 0xff);
drawable = new ColorDrawable(rgb);
}
@Override
public int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
int dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN;
return makeMovementFlags(dragFlags, ItemTouchHelper.ACTION_STATE_IDLE);
}
@Override
public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder srcHolder, RecyclerView.ViewHolder targetHolder) {
this.srcHolder = srcHolder;
return srcHolder.getItemViewType() == targetHolder.getItemViewType() && moveListener.onItemMove(srcHolder.getAdapterPosition(), targetHolder.getAdapterPosition());
}
@Override
public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {
}
@Override
public void onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState) {
super.onSelectedChanged(viewHolder, actionState);
if (actionState == ItemTouchHelper.ACTION_STATE_DRAG) {
viewHolder.itemView.setBackground(null);
}
if (actionState == ItemTouchHelper.ACTION_STATE_IDLE) {
srcHolder.itemView.setBackground(drawable);
}
}
}
实体类代码：
public class ClsOnlineReport {
private String bulletinID;
private String bulletinTime;
private String bulletinTitle;
private String isActive;
private String activeDate;
private String autoCloseDate;
private String modiManID;
private String modiManName;
private String orderNum;
private String onTop;
private String createrID;
private String creater;
private boolean isChecked;
private boolean isCheckBoxVisible;
public ClsOnlineReport() {
}
public String getBulletinID() {
return bulletinID;
}
public void setBulletinID(String bulletinID) {
this.bulletinID = bulletinID;
}
public String getBulletinTime() {
return bulletinTime;
}
public void setBulletinTime(String bulletinTime) {
this.bulletinTime = bulletinTime;
}
public String getBulletinTitle() {
return bulletinTitle;
}
public void setBulletinTitle(String bulletinTitle) {
this.bulletinTitle = bulletinTitle;
}
public String getIsActive() {
return isActive;
}
public void setIsActive(String isActive) {
this.isActive = isActive;
}
public String getActiveDate() {
return activeDate;
}
public void setActiveDate(String activeDate) {
this.activeDate = activeDate;
}
public String getAutoCloseDate() {
return autoCloseDate;
}
public void setAutoCloseDate(String autoCloseDate) {
this.autoCloseDate = autoCloseDate;
}
public String getModiManID() {
return modiManID;
}
public void setModiManID(String modiManID) {
this.modiManID = modiManID;
}
public String getModiManName() {
return modiManName;
}
public void setModiManName(String modiManName) {
this.modiManName = modiManName;
}
public String getOrderNum() {
return orderNum;
}
public void setOrderNum(String orderNum) {
this.orderNum = orderNum;
}
public String getOnTop() {
return onTop;
}
public void setOnTop(String onTop) {
this.onTop = onTop;
}
public String getCreaterID() {
return createrID;
}
public void setCreaterID(String createrID) {
this.createrID = createrID;
}
public String getCreater() {
return creater;
}
public void setCreater(String creater) {
this.creater = creater;
}
public boolean getIsChecked() {
return isChecked;
}
public void setIsChecked(boolean isChecked) {
this.isChecked = isChecked;
}
public boolean getIsCheckBoxVisible() {
return isCheckBoxVisible;
}
public void setIsCheckBoxVisible(boolean isCheckBoxVisible) {
this.isCheckBoxVisible = isCheckBoxVisible;
}
}
适配器布局文件代码：
代码有点多，但并不是很难，没有用设计模式，图片使用Android Studio内置的SVG，引入了ButterKnife绑定控件，另外内部类使用了lambda表达式折叠了，把代码在自己的IDE上面跑一遍，然后尝试修改代码，看看有什么影响，有不懂的可以问我
实现效果：
Movie201905081838_20190508190911.gif