我有一个 RecyclerView,它有一个复选框和文本视图。数字 10,20,30,40... 直到 500 应该显示在文本视图中。选中的复选框应该在文本视图中添加与复选框相对应的数字。例如如果用户仅检查值 10,则 textView 将显示 10。如果用户也检查 20,则 TextView 将显示 30 ( 20 +10)。 如果用户再次取消选中 10,TextView 将显示 20,依此类推。当我单击复选框时,还会选中一些随机复选框。我在 stackoverflow 中尝试了一种解决方案。它不起作用。我被这个问题困住了。请帮助我..这是我的代码:
RecyclerAdapter.java:
public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.RecyclerHolder>
{
@NonNull
@Override
public RecyclerHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
return new RecyclerHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.recycler_lyt,parent,false));
}
@Override
public void onBindViewHolder(@NonNull RecyclerHolder holder, final int position) {
holder.number.setText(Integer.toString((Integer) alldata.get(position)));
final String text=holder.number.getText().toString();
holder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
Log.e("Checked","Checked");
if(checkeddata!=null)
{
if (checkeddata.size()==0)
{
checkeddata.add(text);
}
else {
if(checkeddata.contains(text))
{
checkeddata.remove(text);
}
else {
checkeddata.add(text);
}
}
Iterator iterator=checkeddata.iterator();
int sumnumber=0;
while (iterator.hasNext())
{
sumnumber= sumnumber+Integer.parseInt((String) iterator.next());
}
sum.setText(Integer.toString(sumnumber));
}
}
});
}
@Override
public int getItemCount() {
return alldata.size();
}
public class RecyclerHolder extends RecyclerView.ViewHolder
{
TextView number;
CheckBox checkBox;
public RecyclerHolder(View itemView) {
super(itemView);
number=itemView.findViewById(R.id.number);
checkBox=itemView.findViewById(R.id.check);
}
}
}
public void data()
{
int g=1;
for(int i=10;i<=500;i++)
{
if((i/10)==g)
{
g=g+1;
alldata.add(i);
}
}
}
recycler_lyt.xml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
xmlns:app="http://schemas.android.com/apk/res-auto">
<TextView
android:layout_width="150dp"
android:layout_height="wrap_content"
android:id="@+id/number"
android:textSize="20sp"/>
<CheckBox
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/check"
android:checked="false"
app:layout_constraintRight_toRightOf="parent"/>
</android.support.constraint.ConstraintLayout>
这很正常。您没有将复选框设置为选中或不选中。您正在选择一个,并且视图持有者将其保持为选中状态
你可以看看我的例子。你可以做这样的事情:
@Override
public void onBindViewHolder(ViewHolder holder, final int position) {
final Data data = myItems.get(position);
//in some cases, it will prevent unwanted situations
holder.checkBox.setOnCheckedChangeListener(null);
//if true, your checkbox will be selected, else unselected
holder.checkBox.setChecked(data.isSelected());
holder.checkBox.setOnCheckedChangeListener(new OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
//set your object's last status
data.setSelected(isChecked);
}
});
}
在您的
onBindViewHolder
中,您必须将复选框设置为选中或取消选中。
如果为 true,您的复选框将被选中,否则未选中
holder.checkBox.setChecked(boolean);
您必须存储您的复选框状态。您可以在模型中执行此操作,例如:
class Model {
String title;
boolean checked;
}
接下来,您必须将
List
项目中的 Model
传递给您的适配器,并选中/取消选中由您的型号确定的复选框。
if (listOfItems.get(position).checked) {
viewHolder.checkbox.setChecked(true);
} else {
viewHolder.checkbox.setChecked(false);
}
请记住,您始终需要在适配器中管理相反的视图状态(例如复选框或视图的可见性)。
试试这个:
public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.RecyclerHolder>
{
private OnClickListener onClickListener;
private int sum =0;
@NonNull
@Override
public RecyclerHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
return new RecyclerHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.recycler_lyt,parent,false));
}
@Override
public void onBindViewHolder(@NonNull RecyclerHolder holder, final int position) {
holder.number.setText(Integer.toString((Integer) alldata.get(position)));
final String text=holder.number.getText().toString();
holder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
if(isChecked){
sum += Integer.parseInt(holder.number.getText().toString());
}else{
sum -= Integer.parseInt(holder.number.getText().toString());
}
if (onClickListener != null) {
onClickListener.onItemClick(sum);
}
});
}
@Override
public int getItemCount() {
return alldata.size();
}
public class RecyclerHolder extends RecyclerView.ViewHolder
{
TextView number;
CheckBox checkBox;
public RecyclerHolder(View itemView) {
super(itemView);
number=itemView.findViewById(R.id.number);
checkBox=itemView.findViewById(R.id.check);
}
}
public void setOnClickListener(OnClickListener onClickListener) {
this.onClickListener = onClickListener;
}
public interface OnClickListener {
void onItemClick(int sum);
}
}
现在在活动中使用
adapter
实例,如下所示:
private RecyclerAdapter adapter;
...
...
cardAdapter.setOnClickListener(new CardAdapter.OnClickListener() {
@Override
public void onItemClick(int sum) {
txtSum.setText(String.valueOf(sum));
});
您的模型类中需要有一个字段(例如“isSelected”),以便可以跟踪所有选中的条目。您可以尝试以下操作:
基本上,RecyclerView 会回收视图,因此您需要一个模型来存储复选框的状态。
public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.RecyclerHolder> {
private List<Model> alldata = new ArrayList<>();
@NonNull
@Override
public RecyclerHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
return new RecyclerHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.recycler_lyt, parent, false));
}
@Override
public void onBindViewHolder(@NonNull RecyclerHolder holder, final int position) {
final Model model = alldata.get(position);
holder.number.setText(String.valueOf(model.value));
holder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
model.setChecked(isChecked); // Saves the state of the checkbox.
if (checkeddata != null) {
if (checkeddata.size() == 0) {
checkeddata.add(text);
} else {
if (checkeddata.contains(model.getValue())) {
checkeddata.remove(model.getValue());
} else {
checkeddata.add(model.getValue());
}
}
Iterator iterator = checkeddata.iterator();
int sumnumber = 0;
while (iterator.hasNext()) {
sumnumber = sumnumber + Integer.parseInt((String) iterator.next());
}
sum.setText(Integer.toString(sumnumber));
}
}
});
holder.checkBox.setChecked(model.isChecked()); // Retrieves the state of your checkbox.
}
@Override
public int getItemCount() {
return alldata.size();
}
public class RecyclerHolder extends RecyclerView.ViewHolder {
TextView number;
CheckBox checkBox;
public RecyclerHolder(View itemView) {
super(itemView);
number = itemView.findViewById(R.id.number);
checkBox = itemView.findViewById(R.id.check);
}
}
public void data() {
int g = 1;
for (int i = 10; i <= 500; i++) {
if ((i / 10) == g) {
g = g + 1;
alldata.add(new Model(i));
}
}
}
private class Model {
private int value;
private boolean checked = false;
Model(int value) {
this.value = value;
}
public int getValue() {
return value;
}
public boolean isChecked() {
return checked;
}
public void setChecked(boolean checked) {
this.checked = checked;
}
}
}
如果您进行了必要的更改来存储复选框的状态,则:
在
onBindViewHolder()
中 final String text=holder.number.getText().toString();
之后添加以下内容:
holder.checkBox.setOnCheckedChangeListener(null);
holder.checkBox.setChecked(-- stored value --);
然后添加复选框的监听器。
如果您的 recyclerview 复选框自动更改其值,那么您应该在您的 recyclerview 适配器类中尝试此操作,
@Override
public long getItemId(int position) {
return position;
}
@Override
public int getItemViewType(int position) {
return position;
}