Question

我在自定义listview adaper中的getView（）发生了异步调用，如下所示（最后一行）：

public View getView(final int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
    holder=new Holder();
    View rowView;
    rowView = inflater.inflate(R.layout.list_posts_item, null);

    holder.tvTitle=(TextView) rowView.findViewById(R.id.tvTitleNamePost);
    holder.ivPrimaryImage=(ImageView) rowView.findViewById(R.id.ivPrimaryImage);
    holder.ivPrimaryImage.setId(position);
    holder.ivPrimaryImage.setTag(listOfPosts.get(position).getPostId());
    holder.tvLocality=(TextView) rowView.findViewById(R.id.tvLocalityPosts);
    holder.tvDateCreated=(TextView) rowView.findViewById(R.id.tvDateCreated);


    holder.tvTitle.setText(listOfPosts.get(position).getTitle());
     holder.ivPrimaryImage.setImageBitmap(listOfPosts.get(position).getImage());

    holder.tvLocality.setText(listOfPosts.get(position).getLocality());
    holder.tvDateCreated.setText(listOfPosts.get(position).getCreatedDate());
    postId = listOfPosts.get(position).getPostId();
    Image image = new Image();
    image.setImg(holder.ivPrimaryImage);
    if(!"N".equalsIgnoreCase(listOfPosts.get(position).getHasImage()))
        new GetPrimaryImages().execute(image);
    return rowView;
}

问题是，每次执行getView时都会发生异步调用。只有当考虑的项目是imageView时，我们才能限制通话吗？

Answer 1

你不应该真正从getView（）调用异步，尽量保持尽可能轻，并尝试通过正确使用viewholders和recycler视图尽可能少地调用它。我不是百分之百完成你剩下的代码的方式，所以这里有一个很好的run through of all the details.网上有很多其他的深度解释，将通过你需要了解的有关getView（）性能的所有内容。

Answer 2

这有助于：

  def writeToKafka[K: ClassTag, V: ClassTag](rdd: RDD[(K, V)], topic: String, keySerializerClass: String, valueSerializerClass: String, brokers: String = producerBroker) = {
    rdd.foreachPartition { partitionOfRecords =>
      val producerProps: Properties = new Properties
      producerProps.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, brokers)
      producerProps.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, keySerializerClass)
      producerProps.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, valueSerializerClass)
      val producer = new KafkaProducer[K, V](producerProps)
      partitionOfRecords.foreach { message =>
        producer.send(new ProducerRecord[K, V](topic, message._1, message._2))
      }
      producer.close()
    }
  }

在我的ListView定义中。将它改为fill_parent / match_parent会避免它。

如何限制getView中特定项的某些代码的执行？

2 个答案: