Android RecyclerView复选框会自动检查

必须存储复选框状态。可以在模型中执行此操作,例如:

class Model {
    String title;
    boolean checked;
}

下一步你必须通过 List Model 将项目添加到适配器,然后选中/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视图的相反状态(如复选框或视图的可见性)。

这很正常。您没有将复选框设置为选中状态。您正在选择一个,视图保持器保持选中状态

你可以看看我的例子。你可以这样做:

@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);
            }
        });

    }

在你的 onBindViewHolder 如果为true,则选中复选框,否则取消选中

holder.checkBox.setChecked(boolean);

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);
    }
}

adapter

private RecyclerAdapter adapter;
...
...
cardAdapter.setOnClickListener(new CardAdapter.OnClickListener() {
        @Override
        public void onItemClick(int sum) {
            txtSum.setText(String.valueOf(sum));
    });

您需要在模型类中有一个字段(比如“isSelected”),这样所有选中的条目都可以跟踪。你可以尝试以下操作:

checkboxRecyclerView

基本上,RecyclerView循环使用视图,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以存储复选框的状态,则:
在里面 onBindViewHolder() final String text=holder.number.getText().toString(); 添加以下内容:

holder.checkBox.setOnCheckedChangeListener(null);
holder.checkBox.setChecked(-- stored value --);

然后为复选框添加侦听器。