如何将 OnClickListener 添加到 CardView？

Question

我正在与RecyclerView 和CardView 合作。我想在每张卡片上附加OnClickListner。我在stackoverflow上尝试了许多可用的答案，但它们对我不起作用。到目前为止，我已经尝试过 -

public class SubjectAdapter extends RecyclerView.Adapter<SubjectAdapter.ViewHolder> implements View.OnClickListener,
    View.OnLongClickListener{

private static final String LOGCAT = "SubjectAdapter";
private final Context mContext;

List<Subject> SubjectsList;

public SubjectAdapter(Context context) {
    super();
    this.mContext = context;
    SQLiteDatabase.loadLibs(mContext);
    DBHelper myDbHelper = new DBHelper(mContext);
    SubjectsList = new ArrayList<Subject>();
    SubjectsList = myDbHelper.getAllSubjects();
    myDbHelper.close();
}

@Override
public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
    View v = LayoutInflater.from(viewGroup.getContext())
            .inflate(R.layout.subject_cardview_row, viewGroup, false);
    ViewHolder viewHolder = new ViewHolder(v);

    // Below two lines are NOT working
    viewHolder.tvSubjectName.setOnClickListener(this);
    //viewHolder.setOnClickListener(this);

    return viewHolder;
}

@Override
public void onBindViewHolder(ViewHolder viewHolder, int i) {
    Subject subject = SubjectsList.get(i);
    viewHolder.tvSubjectName.setText(subject.getSubject_Name());
    viewHolder.tvCounts.setText(String.valueOf(subject.getSubject_Number_of_Questions()));

    // Below two lines are NOT working
    viewHolder.tvSubjectName.setOnClickListener(this);
    //viewHolder.setOnClickListener(this);
}

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

@Override
public void onClick(View v) {
    // It's not working either
    ViewHolder holder = (ViewHolder) v.getTag();
    int position = holder.getPosition();

    if (v.getId() == holder.tvSubjectName.getId()){
        Log.d(LOGCAT, "tvSubjectName onClick at" + position);
        //Toast.makeText(mContext, "tvSubjectName onClick at" + position, Toast.LENGTH_LONG).show();
    } else {
        Log.d(LOGCAT, "RecyclerView Item onClick at " + position);
        //Toast.makeText(mContext, "RecyclerView Item onClick at " + position, Toast.LENGTH_LONG).show();
    }
}

@Override
public boolean onLongClick(View v) {
    return false;
}

class ViewHolder extends RecyclerView.ViewHolder {

    public TextView tvSubjectName;
    public TextView tvCounts;

    public ViewHolder(View itemView) {
        super(itemView);
        tvSubjectName = (TextView) itemView.findViewById(R.id.tv_subject_name);
        tvCounts = (TextView) itemView.findViewById(R.id.tv_text_counts);
    }
}
}

正如大家所看到的，我尝试了setOnClickListener 与onCreateViewHolder 和onBindViewHolder，也作为单独的onClick，但它们似乎都不适合我。所以，我想知道，如何将 OnClickListner 添加到 CardView？

Answer 1

onClick 返回的视图不一定对应回收站视图的视图行层次结构。 我认为你应该用

修改onBindViewHolder

@Override
public void onBindViewHolder(final ViewHolder viewHolder, final int i) {
   final Subject subject = SubjectsList.get(i); 
   viewHolder.tvSubjectName.setOnClickListener(new View.OnClickListener(){


    @Override
    public void onClick(View v) {
        Log.d(LOGCAT, "tvSubjectName onClick at" + i);
       // etc
    }

   });
...
}

如果您使用长按，请将View.OnClickListener 替换为View.OnLongClickListener，将onClick 替换为onLongClick。

Answer 2

这对我有用！ 将 setOnClickListener-method 放入 ViewHolder 类的构造函数中。

class ViewHolder extends RecyclerView.ViewHolder
{
    public TextView tvSubjectName;
    public TextView tvCounts;

    public ViewHolder(View itemView) 
    {
        super(itemView);
        tvSubjectName = (TextView) itemView.findViewById(R.id.tv_subject_name);
        tvCounts = (TextView) itemView.findViewById(R.id.tv_text_counts);

        itemView.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View v)
            {
                 //write here the code for wathever you want to do with a card
                 //...
            }
        });

}

}

Answer 3

查看 Lucas Rocha 的新 TwoWayView API。

TwoWayLayoutManager 是 LayoutManager 之上的一个简单 API，它为您完成所有繁重的工作，因此您可以专注于如何测量、放置子视图以及从 RecyclerView 分离。

Follow his site 和 API 的实现相对简单，可能会帮助您解决 RecyclerView 和 CardView 构成的一些困难的复杂性。

http://lucasr.org/2014/07/31/the-new-twowayview/

Answer 4

在 RecyclerView.ViewHolder 构造函数中将 OnClickListener 设置为 itemView，您也可以使用 getAdapterPosition() 方法获取 cardView 的位置，这可以帮助您使用 putExtra 意图方法将数据传递给新活动。 doc for getAdapterPosition method

`

class ViewHolder extends RecyclerView.ViewHolder
{
    public TextView tvSubjectName;
    public TextView tvCounts;

    public ViewHolder(View itemView) 
    {
        super(itemView);
        tvSubjectName = (TextView) itemView.findViewById(R.id.tv_subject_name);
        tvCounts = (TextView) itemView.findViewById(R.id.tv_text_counts);

        itemView.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View v)
            {
                 int position = getAdapterPosition();
                 // use position to put extra data
            }
        });
}

`

Answer 5

如果您真的想实现 onclick 监听器，请执行以下操作

1. 在 ViewHolderClass 中添加一个 View 对象并将其初始化为在构造函数中收到的 itemView

2.setOnClickListener 到你在 Adapter 类中声明的视图对象（在 ViewHolder 中）onBindViewHolder

这将适用于整个 cardView