android - 从 BaseAdapter 更新活动中的 textView

Question

我有一个适配器可以在扩展 BaseAdapter 的 ListView 中呈现值。这个适配器在一个活动中被调用。Activity 有一个 TextView，当在 Adapter 中调用 onClickListener 时需要更新它。如果在适配器中单击按钮，有人可以让我知道如何更新 TextView。任何例子都会有所帮助。谢谢。

代码

private class ViewItem extends Activity{
ImageButton addToCart;
ViewItem(View convertView,final int position)
    {
addToCart.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View v) {
itemPosition=Integer.parseInt(positionView.getText().toString());
                    int qty = Integer.parseInt(quantity.getText().toString());
                    ShoppingCartHelper.setQuantity(itemPosition, qty);
                    ShoppingCartHelper.itemsInTheCart = ShoppingCartHelper.cartMap.size();
                    Toast.makeText(v.getContext(), "Successfully, Item added to the Cart...", Toast.LENGTH_SHORT).show();
//I need to update a TextView here                      

                    // Close the activity
                    finish();
                }
            });

Answer 1

尝试这个，

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


        EvenViewHolder holdereven;
        if (convertView == null) {
            convertView = mInfaltor.inflate(R.layout.schedule_adapter_view,
                    null);
            holdereven = new EvenViewHolder();
            holdereven.time = (TextView) convertView
                    .findViewById(R.id.time);
            holdereven.title = (TextView) convertView
                    .findViewById(R.id.title);
            holdereven.des = (TextView) convertView.findViewById(R.id.des);
 holdereven.time.setOnClickListener(new View.OnClickListener(
                    ) {

                @Override
                public void onClick(View v) {
                    // TODO Auto-generated method stub
                    //Do your stuff
                }
            });
            convertView.setTag(holdereven);

        } else {
            holdereven = (EvenViewHolder) convertView.getTag();
        }
  static class EvenViewHolder {
    TextView time, title, des;

  }
  }