Question

我正在尝试在listView中的项目上设置和onClick侦听器但是出于某种原因，单击它们时从不出现toast。我不确定在这个例子中到底发生了什么，但是非常感谢任何建议。

源：

public class CustomListViewAdapter extends ArrayAdapter<Cmd> {
    Activity context;
    List<Cmd> videos;

    public CustomListViewAdapter(Activity context, List<Cmd> videos) {
        super(context, R.layout.list_item2, videos);

        this.context = context;
        this.videos = videos;
    }

    /* private view holder class */
    private class ViewHolder {
        ImageView imageView;
        TextView txtSuccess;
        TextView txtCmd;
        TextView txtPrice;
    }

    public Cmd getItem(int position) {
        return videos.get(position);
    }

    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;
        LayoutInflater inflater = context.getLayoutInflater();
        if (convertView == null) {
            convertView = inflater.inflate(R.layout.list_item2, null);
            holder = new ViewHolder();
            holder.txtSuccess = (TextView) convertView
                    .findViewById(R.id.success);
            holder.txtCmd = (TextView) convertView.findViewById(R.id.cmd);
            holder.txtPrice = (TextView) convertView.findViewById(R.id.price);
            holder.imageView = (ImageView) convertView
                    .findViewById(R.id.thumbnail);
            convertView.setTag(holder);

        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        Cmd cmd = (Cmd) getItem(position);

        holder.txtSuccess.setText(cmd.getVideoName());
        holder.txtCmd.setText(cmd.getCmd());
        // holder.imageView.setImageBitmap(cmd.getImageBitmap());
        holder.txtPrice.setText(cmd.getVideoURL() + "");
        holder.imageView.setOnClickListener(new View.OnClickListener() {

            public void onClick(View v) {
                Toast.makeText(context, "Clicked on image", Toast.LENGTH_LONG)
                        .show();
            }
        });
        return convertView;


    }
}

Answer 1

使您的ImageView可点击且可对焦

Answer 2

您可以在几个地方改进ViewHolder模式的使用。首先，每次调用getView时都会重置onClickListener()。您应该进行以下更改：

   @Override
   public View getView(int position, View convertView, ViewGroup parent) {
         View view = null;

         if(convertView == null){
              view = context.getLayoutInflater().inflate(R.layout.list_item2, null);

                final ViewHolder holder = new ViewHolder();
                holder.txtSuccess = (TextView) view
                        .findViewById(R.id.success);
                holder.txtCmd = (TextView) view.findViewById(R.id.cmd);
                holder.txtPrice = (TextView) view.findViewById(R.id.price);
                holder.imageView = (ImageView) view.findViewById(R.id.thumbnail);
                holder.imageView.setOnClickListener(new View.OnClickListener() {
                   public void onClick(View v) {
                    Toast.makeText(context, "Clicked on image", Toast.LENGTH_LONG)
                            .show();
                    }
                 });
                view.setTag(holder);
         } else {
             view = convertView;
         }

            ViewHolder holder = (ViewHolder) view.getTag();

            Cmd cmd = (Cmd) getItem(position);

            holder.txtSuccess.setText(cmd.getVideoName());
            holder.txtCmd.setText(cmd.getCmd());
            // holder.imageView.setImageBitmap(cmd.getImageBitmap());
            holder.txtPrice.setText(cmd.getVideoURL() + "");

            return view;

    }

此外，您应该使ViewHolder内部类静态。

/* private view holder class */
private static class ViewHolder {
    ImageView imageView;
    TextView txtSuccess;
    TextView txtCmd;
    TextView txtPrice;
}

Answer 3

尝试实施触摸，而不是点击或使用ImageButton代替ImageView

    holder.imageView.setOnTouchListener(new OnTouchListener() {
        @Override
        public boolean onTouch(View arg0, MotionEvent arg1) {
            switch (arg1.getAction()) {
            case MotionEvent.ACTION_DOWN: {
                 Toast.makeText(context, "Clicked on image", Toast.LENGTH_LONG)
                    .show();
                break;

            }
            }
            return true;
        }
    });

onClick侦听器不显示Toast

源：

3 个答案: