Android listview 使用 Retrofit 无限滚动

Question

我目前的项目需要你的帮助。要求是使列表视图分页并在向下滚动时加载其他数据，就像 Facebook 和 Twitter 应用程序所做的那样。

这是我目前尝试过的方法：

MainActivity

listView.setOnScrollListener(new InfiniteScrollListener() {
        public boolean onLoadMore(int page, int totalItemsCount) {
            // Triggered only when new data needs to be appended to the list
            // Add whatever code is needed to append new items to your AdapterView
            customLoadMoreDataFromApi(page);
            // or customLoadMoreDataFromApi(totalItemsCount);
            return true; // ONLY if more data is actually being loaded; false otherwise.
        }
    });


 private void getData() {
    if(ConnectionDetector.hasNetworkConnection(getActivity())) {
        RestAdapter restAdapter = new RestAdapter.Builder()
                .setEndpoint(HOME_DOMAIN)
                .setLogLevel(RestAdapter.LogLevel.FULL)
                .build();

        WebServices service = restAdapter.create(WebServices.class);

        service.getRecords(
                "1", // Row
                "10", // Count
                new Callback<World>() {
                    @Override
                    public void success(Som som, Response response) {
                        dataList = Parser.getResponseBody(response);
                        adapter = new SomAdapter(getActivity(), dataList);
                        listView.setAdapter(adapter);
                    }

                    @Override
                    public void failure(RetrofitError retrofitError) {
                        Log.e(TAG, "" + retrofitError.toString());
                    }
                });

    } else {
        Toast.makeText(getActivity(),
                getActivity().getResources().getString(R.string.connection_error),
                Toast.LENGTH_SHORT).show();
    }

}

// Append more data into the adapter
public void customLoadMoreDataFromApi(int offset) {
    // This method probably sends out a network request and appends new data items to your adapter.
    // Use the offset value and add it as a parameter to your API request to retrieve paginated data.
    // Deserialize API response and then construct new objects to append to the adapter
    getData();
    moreProgress.setVisibility(View.VISIBLE);
    Log.e(TAG, "MORE PROGRESS");
}

InfiniteScrollListener:

public abstract class InfiniteScrollListener implements AbsListView.OnScrollListener {

private int bufferItemCount = 10;
private int currentPage = 0;
private int itemCount = 0;
private boolean isLoading = true;

public InfiniteScrollListener(int bufferItemCount) {
    this.bufferItemCount = bufferItemCount;
}

public abstract void loadMore(int page, int totalItemsCount);

@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
    // Do Nothing
}

@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount)
{
    if (totalItemCount < itemCount) {
        this.itemCount = totalItemCount;
        if (totalItemCount == 0) {
            this.isLoading = true; }
    }

    if (isLoading && (totalItemCount > itemCount)) {
        isLoading = false;
        itemCount = totalItemCount;
        currentPage++;
    }

    if (!isLoading && (totalItemCount - visibleItemCount)<=(firstVisibleItem + bufferItemCount)) {
        loadMore(currentPage + 1, totalItemCount);
        isLoading = true;
    }
}

}

向下滚动时显示进度条。这可行，但我还需要将下一个获取的数据附加到列表视图。我该怎么做？我需要你的建议，因为这是我第一次在 Android 中进行分页。谢谢！

Answer 1

你做对了一切。但是不需要创建新的 SomAdapter，你只需要将新获取的数据添加到它

@Override
public void success(Som som, Response response) {
   dataList = Parser.getResponseBody(response);
   if (adapter == null) {
      adapter = new SomAdapter(getActivity(),dataList);
      listView.setAdapter(adapter);
   } else {
      adapter.addAll(dataList);
   }
}

如果您制作自定义适配器而不是扩展 ArrayAdapter，请确保您的 addAll 方法具有 notifyDataSetChanged.

更改 getData() 以获取参数偏移量和分页请求逻辑。

Android listview 使用 Retrofit 无限滚动

Android listview infinite scrolling using Retrofit

android

listview

retrofit