我使用布尔概念来交换回收物品中的文本字段，

Question

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ContactViewHolder> {

    static final String myTag = "DocsUpload";
    ArrayList<RecyclerItem> listItems = new ArrayList<>();
    RecyclerView.ViewHolder holder;
    int clickcount=0;
    private Context mContext;
    List list = new ArrayList();
    Boolean signUpModeActive = true;

    public MyAdapter(ArrayList<RecyclerItem> listItems, Context mContext) {
        this.listItems = listItems;
        this.mContext = mContext;
    }

    @Override
    public ContactViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.recycler_item, parent, false);

        ContactViewHolder contactViewHolder = new ContactViewHolder(view, mContext, listItems);
        return contactViewHolder;
    }

    @Override
    public void onBindViewHolder(final ContactViewHolder holder, final int position) {

        RecyclerItem itemList = listItems.get(position);
        holder.txtTitle.setText(itemList.getTitle());
    }

    @Override
    public int getItemCount() {
        return listItems.size();
    }

    public class ContactViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {

        public TextView txtTitle;
        public CheckBox checkBox;
        public TextView txtDescription;
        public ImageView txtOptionDigit;
        ArrayList<RecyclerItem> listitems = new ArrayList<RecyclerItem>();

        Context ctx;

        public ContactViewHolder(View view, Context ctx, ArrayList<RecyclerItem> listitems) {
            super(view);
            this.listitems = listitems;
            this.ctx = ctx;
            view.setOnClickListener(this);

            txtTitle = (TextView) itemView.findViewById(R.id.txtTitle);
            checkBox = (CheckBox) itemView.findViewById(R.id.checkBoxxml);
        }

        boolean m=false;
        @Override
        public void onClick(View v) {
            clickcount=clickcount+1;

            Log.e("count", String.valueOf(clickcount));
            int position = getAdapterPosition();
            final RecyclerItem listitems = this.listitems.get(position);
            final String getname = listitems.getTitle();

            if (signUpModeActive=true) {

                signUpModeActive = false;
                listItems.get(position).setTitle("");
                listItems.get(position).setTitle(getname + " " +"absent");

            } else {

                signUpModeActive = true;
                listItems.get(position).setTitle("");
                listItems.get(position).setTitle(getname + " " +"present");
            }


            notifyDataSetChanged();
        }

    }

    public void getsetadapt(String pos) {

        list.add(pos);
        Log.e("listdata", String.valueOf(list));


        for (int i=0;i < list.size();i++)
        {
            Log.i("Value "+i, String.valueOf(list.get(i)));

            i++;

        }
    }

当我点击任何列表项时，它想要添加缺少现有文本，如果我再次点击它想要替换缺席现在..可以任何人知道我哪里出错...如果在我的模拟器上运行此代码它工作和它正在添加不替换的文本。例如，如果我点击学生oviya它添加文本缺席oviya附近但是如果我再次点击它不是替换它正在一次又一次地添加礼物

Answer 1

只需将适配器更改为以下适配器，它就可以正常工作

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ContactViewHolder> {

static final String myTag = "DocsUpload";
ArrayList<RecyclerItem> listItems = new ArrayList<>();
RecyclerView.ViewHolder holder;
int clickcount = 0;
private Context mContext;
List list = new ArrayList();
Boolean signUpModeActive = true;

public MyAdapter(ArrayList<RecyclerItem> listItems, Context mContext) {
    this.listItems = listItems;
    this.mContext = mContext;
}

@Override
public ContactViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.recycler_item_2, parent, false);

    ContactViewHolder contactViewHolder = new ContactViewHolder(view, mContext, listItems);
    return contactViewHolder;
}

@Override
public void onBindViewHolder(final ContactViewHolder holder, final int position) {

    RecyclerItem itemList = listItems.get(position);
    holder.txtTitle.setText(itemList.getTitle());
}

@Override
public int getItemCount() {
    return listItems.size();
}


public class ContactViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {

    public TextView txtTitle;
    public CheckBox checkBox;
    public TextView txtDescription;
    public ImageView txtOptionDigit;
    ArrayList<RecyclerItem> listitems = new ArrayList<RecyclerItem>();

    Context ctx;

    public ContactViewHolder(View view, Context ctx, ArrayList<RecyclerItem> listitems) {
        super(view);
        this.listitems = listitems;
        this.ctx = ctx;
        view.setOnClickListener(this);

        txtTitle = (TextView) itemView.findViewById(R.id.txtTitle);
        checkBox = (CheckBox) itemView.findViewById(R.id.checkBoxxml);
    }

    boolean m = false;

    @Override
    public void onClick(View v) {
        clickcount = clickcount + 1;


        Log.e("count", String.valueOf(clickcount));
        int position = getAdapterPosition();
        final RecyclerItem listitems = this.listitems.get(position);
        final String getname = listitems.getTitle().replace(" absent" , "").replace(" present" , "");

        if (signUpModeActive ) {

            signUpModeActive = false;
            listItems.get(position).setTitle(getname + " " + "absent");

        } else {

            signUpModeActive = true;
            listItems.get(position).setTitle(getname + " " + "present");
        }


        notifyDataSetChanged();
    }

}

public void getsetadapt(String pos) {

    list.add(pos);
    Log.e("listdata", String.valueOf(list));


    for (int i = 0; i < list.size(); i++) {
        Log.i("Value " + i, String.valueOf(list.get(i)));

        i++;

    }
}

}

实际上问题是排队的

final RecyclerItem listitems = this.listitems.get(position);
        final String getname = listitems.getTitle();

你把文字设置为

 listItems.get(position).setTitle(getname + " " + "absent");

要么

 listItems.get(position).setTitle(getname + " " + "present");

这将导致名称缺席或名称作为结果出现，并将添加新的缺席或呈现给它

Answer 2

您的代码中存在不同的问题。

1首先，您的变量未正确命名，因此非常混乱。例如，你使用几乎完全相同的listitems和listItems。加上listitems两次使用两个不同的变量，在相同的范围内使用完全相同的情况！

变量应描述其内容（您应该了解读取名称时的内容，例如学生列表不会被命名为'list'而是'student'或'studentsList'）并且您应该避免使用2个变量同一范围内的完全相同的名称（如果你必须开始做类似this.myvariable = myvariable的事情，那就意味着你的实现中出了问题）。

2以不同方式管理标题

您想要的是名称+状态取决于是否存在。

所以当你这样做时：

listItems.get(position).setTitle("");

你只是将名称松散为listItems，listitems是完全相同的列表。

所以我建议在getName()上使用RecyclerItem方法来返回名称。删除set/getTitle。

然后用布尔值管理当前/缺席。基本上，就像那样：

if (signUpModeActive = true) {
    signUpModeActive = false;
    item.setIsPresent(false);
} else {
    signUpModeActive = true;
    item.setIsPresent(true);
}

这意味着你需要在setIsPresent中添加RecyclerItem方法。

然后你，在onBindViewHolder你做：

@Override
public void onBindViewHolder(final ContactViewHolder holder, final int position) {
    RecyclerItem item = mListItems.get(position);

    String name = item.getName();
    String status = item.isPresent() ? "present" : "absent";
    String title = name + " " + status;

    holder.txtTitle.setText(title);
}

使用带占位符的字符串资源来管理状态文本会更好。