Question

我有一个RecyclerView，其中有一个复选框和textview.10,20,30,40 ...直到500的数字应显示在textview中.Checked复选框应在与该复选框相对应的textview中添加数字。。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，则TextView将显示20，依此类推。当我单击复选框时，也会选中一些随机复选框。我在stackoverflow中尝试了一种解决方案。它没有用。我对此感到困惑。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>

Answer 1

您必须存储复选框状态。您可以在模型中做到这一点，例如：

class Model {
    String title;
    boolean checked;
}

接下来，您必须将List个项目中的Model个传递给适配器，并选中/取消选中由您的模型确定的复选框。

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）。

Answer 2

很正常。您没有选择复选框。您正在选择一个，并且视图持有者将其保持选中状态

您可以看一下我的例子。您可以执行以下操作：

@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onBindViewHolder内，您必须选中或未选中复选框。如果为true，则会选中您的复选框，否则未选中

holder.checkBox.setChecked(boolean);

Answer 3

尝试一下：

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));
    });

Answer 4

您需要在模型类中有一个字段（例如“ isSelected”），以便可以跟踪所有选中的条目。您可以尝试执行以下操作：

checkboxRecyclerView

Answer 5

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;
        }
    }
}

Answer 6

如果进行了必要的更改以存储复选框的状态，则：
在onBindViewHolder()之后的final String text=holder.number.getText().toString();中添加以下内容：

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

，然后为该复选框添加侦听器。

Android RecyclerView复选框会自行检查

6 个答案: