Recyclerview单选和多选
思路
单选的时候：在adapter中声明一个变量lastClickPosition记住点击的是哪个位置的item，在getView（）方法中，如果lastClickPosition =position,则imageVIew.setImageResource(R.drawable.icon)
多选的时候：建立一个bean文件，生明一个 isSelected变量，通过在数据中保存这个状态，来知道哪个item被选中了。
单选代码：
public class ListViewActivity extends AppCompatActivity {
private List <String> mDate=new ArrayList<>();
private ListAdapter listAdapter;
@Override
protected void onCreate(@Nullable final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.list_activity);
ListView listView = findViewById(R.id.lv);
for(int i=0;i<100;i++){
mDate.add("item"+i);
}
listAdapter = new ListAdapter(this,mDate);
listView.setAdapter(listAdapter);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
listAdapter.singleChoose(position);
}
});
}
}
adapter
public class ListAdapter extends BaseAdapter {
private Context context;
private List<String> mDates;
private LayoutInflater mLayoutInflater;
private int lastClickPosition=-1;
public ListAdapter(Context context, List mDates) {
this.context = context;
this.mDates = mDates;
mLayoutInflater = LayoutInflater.from(context);
}
public void singleChoose(int position){
lastClickPosition = position;
notifyDataSetChanged();
}
@Override
public int getCount() {
return mDates==null?0:mDates.size();
}
@Override
public Object getItem(int position) {
return getItem(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder;
if(convertView==null){
viewHolder = new ViewHolder();
convertView = mLayoutInflater.inflate(R.layout.item_list,parent,false);
viewHolder.tvItem = convertView.findViewById(R.id.tvItem);
viewHolder.imageView = convertView.findViewById(R.id.imageView);
convertView.setTag(viewHolder);
}else {
viewHolder = (ViewHolder) convertView.getTag();
}
if(position==lastClickPosition){
viewHolder.imageView.setImageResource(R.drawable.check);
}else {
viewHolder.imageView.setImageResource(R.drawable.nocheck);
}
viewHolder.tvItem.setText(mDates.get(position));
return convertView;
}
static class ViewHolder{
private TextView tvItem;
private ImageView imageView;
}
}
多选代码
public class ListMultipleViewActivity extends AppCompatActivity {
private List <ListItemBean> mDate=new ArrayList<>();
private ListMultipleAdapter listAdapter;
private TextView tvClickNum;
@Override
protected void onCreate(@Nullable final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.list_activity);
ListView listView = findViewById(R.id.lv);
tvClickNum = findViewById(R.id.tvClickNum);
for(int i=0;i<100;i++){
ListItemBean listItemBean = new ListItemBean();
listItemBean.setSelected(false);
listItemBean.setItemName("item"+i);
mDate.add(listItemBean);
}
listAdapter = new ListMultipleAdapter(this,mDate);
listView.setAdapter(listAdapter);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
listAdapter.multipleChoose(position);
}
});
tvClickNum.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
int num=0;
Iterator iterator = mDate.iterator();
while (iterator.hasNext()){
ListItemBean listItemBean = (ListItemBean) iterator.next();
if(listItemBean.isSelected()){
num++;
}
}
if(num>0){
tvClickNum.setText("统计:被选中的item数量是"+num+"个");
}
}
});
}
}
多选adapter
public class ListMultipleAdapter extends BaseAdapter {
private Context context;
private List<ListItemBean> mDates;
private LayoutInflater mLayoutInflater;
private int lastClickPosition = -1;
public ListMultipleAdapter(Context context, List mDates) {
this.context = context;
this.mDates = mDates;
mLayoutInflater = LayoutInflater.from(context);
}
public void multipleChoose(int position) {
ListItemBean listItemBean = mDates.get(position);
if (listItemBean.isSelected()) {
listItemBean.setSelected(false);
} else {
listItemBean.setSelected(true);
}
notifyDataSetChanged();
}
@Override
public int getCount() {
return mDates == null ? 0 : mDates.size();
}
@Override
public Object getItem(int position) {
return getItem(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder;
if (convertView == null) {
viewHolder = new ViewHolder();
convertView = mLayoutInflater.inflate(R.layout.item_list, parent, false);
viewHolder.tvItem = convertView.findViewById(R.id.tvItem);
viewHolder.imageView = convertView.findViewById(R.id.imageView);
convertView.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
if (mDates.get(position).isSelected()) {
viewHolder.imageView.setImageResource(R.drawable.check);
} else {
viewHolder.imageView.setImageResource(R.drawable.nocheck);
}
viewHolder.tvItem.setText(mDates.get(position).getItemName());
return convertView;
}
static class ViewHolder {
private TextView tvItem;
private ImageView imageView;
}
}
item布局文件
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_margin="12dp">
<ImageView
android:id="@+id/imageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_centerVertical="true"
android:src="@drawable/item_selector" />
<TextView
android:id="@+id/tvItem"
android:layout_marginLeft="12dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_toRightOf="@+id/imageView"
tools:text="617283649821" />
</RelativeLayout>
</LinearLayout>
listview_activity
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:padding="12dp"
android:id="@+id/tvClickNum"
android:text="统计:"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<ListView
android:id="@+id/lv"
android:layout_width="match_parent"
android:layout_height="match_parent"></ListView>
</LinearLayout>
demo下载
https://download.csdn.net/download/qq_26296197/10840545
