Android Spinner动态添加按钮，点击报错

不多说，贴代码

//数据源
 private ArrayList<String> mKeyWords=new ArrayList<String>();
 //适配器
 class KeyWordsAdapter extends BaseAdapter{
        private TextView tvKeyWords;
        @Override
        public int getCount() {
            // TODO Auto-generated method stub
            if(mKeyWords==null){
                return 0;
            }else{
                return mKeyWords.size();
            }

        }

        @Override
        public String getItem(int position) {
            // TODO Auto-generated method stub
            return mKeyWords.get(position);
        }

        @Override
        public long getItemId(int position) {
            // TODO Auto-generated method stub
            return position;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            // TODO Auto-generated method stub

            if(convertView==null){
                convertView=View.inflate(CommentFliterActivity.this, R.layout.key_item, null);
                tvKeyWords=(TextView) convertView.findViewById(R.id.tv_key);
                convertView.setTag(tvKeyWords);
            }else{
                tvKeyWords=(TextView) convertView.getTag();
            }
            tvKeyWords.setText(getItem(position));
            return convertView;
        }

    }


    //添加按钮
    addButton.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                String text = mKeys.getText().toString();
                if(mKeyWords.size()==8){
                    Toast.makeText(CommentFliterActivity.this, "关键字数量已达上限，不能继续输入", Toast.LENGTH_SHORT).show();
                    mKeys.setText("");
                }else{
                    mKeyWords.add(text);
                    mKeys.setText("");
                    mAdapter.notifyDataSetChanged();
                    mSpinner.setSelection(mKeyWords.size()-1, true);
                }
            }
        });

每次一点击添加按钮就崩溃了

135行代码为空，看看是不是布局绑定错了