我的需求是我在Recycler中充气JSON数据。好的。现在我想要一个指示符LIKE THIS STYLE，它将显示您在RecyclerView中有多少项目。当一件物品已经被戴上或当前时，指示器将被点燃，当使用向下滚动时，其顶部选定的位置项目将是明智的。请帮助我如何做到这一点..
我的适配器方法
@Override
public MessageAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.custom_message, parent, false);
return new ViewHolder(itemView);
}
@Override
public void onBindViewHolder(MessageAdapter.ViewHolder holder, int position) {
/*Tuesday, April 10, 2001 3:51 PM*/
msgModels = msgList.get(position);
if (msgList.get(position) != null) {
holder.msgTitle.setText(msgModels.getMessageTitle());
holder.msgDescription.setText(msgModels.getMessageDescription());
holder.msgDate.setText(msgModels.getMessageDate());
//
}
if (firstVisible==position) {
holder.msgTitle.setTextColor(Color.RED);
holder.msgDescription.setTextColor(Color.RED);
holder.msgDate.setTextColor(Color.RED);
holder.layerLyt.setAlpha(1);
}
if (position==msgList.size()-1) {
holder.msgTitle.setTextColor(Color.RED);
holder.msgDescription.setTextColor(Color.RED);
holder.msgDate.setTextColor(Color.RED);
holder.layerLyt.setAlpha(1);
}
else{
holder.msgTitle.setTextColor(Color.BLUE);
holder.msgDescription.setTextColor(Color.BLUE);
holder.msgDate.setTextColor(Color.BLUE);
holder.layerLyt.setAlpha(0.2f);
}
}
@Override
public int getItemCount() {
return msgList.size();
}
private int firstVisible = 0;
private int lastVisible ;
public void changeItem(int position){
firstVisible = position;
notifyItemChanged(firstVisible);
notifyDataSetChanged();
} public void changeLastItem(int position){
lastVisible = position;
notifyItemChanged(lastVisible);
notifyDataSetChanged();
}
public class ViewHolder extends RecyclerView.ViewHolder {
public TextView msgTitle, msgDescription,msgDate;
public RelativeLayout layerLyt;
public ViewHolder(View view) {
super(view);
msgTitle = (TextView)view.findViewById(R.id.msgTitle);
msgDescription = (TextView)view.findViewById(R.id.msgDescription);
layerLyt = (RelativeLayout) view.findViewById(R.id.layerLyt);
msgDate = (TextView)view.findViewById(R.id.msgDate);
}
}
我的片段
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_message, null);
mRecyclerView = (RecyclerView) view.findViewById(R.id.recycler_viewLaws);
linearLayoutManager = new LinearLayoutManager(getActivity());
mRecyclerView.setLayoutManager(linearLayoutManager);
mRecyclerView.setAdapter(msgAdapter);
msgAdapter = new MessageAdapter(msgList, getActivity(), this);
//msgAdapter.notifyDataSetChanged();
mProgressDialog = new ProgressDialog(getActivity());
mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
LinearLayoutManager manager = (LinearLayoutManager) recyclerView.getLayoutManager();
int firstVisible = manager.findFirstVisibleItemPosition();
int lastVisible = manager.findLastVisibleItemPosition();
Log.i("TAG", "onScrolled: " + firstVisible);
Log.i("TAG", "Last Index: " + lastVisible);
msgAdapter.changeItem(firstVisible);
msgAdapter.changeLastItem(lastVisible);
}
});
if (NetworkCheck.getInstant(getActivity()).isConnectingToInternet()) {
loadAPI();
} else {
ErrorMessageDialog.getInstant(getActivity()).show("No Network");
}
return view;
}
private void loadAPI() {
mProgressDialog.setMessage("Loading...");
mProgressDialog.setCancelable(false);
mProgressDialog.show();
new PostStringRequest(getActivity(), setMessagePostBody(), this, API_MSG_CALL, NetworkUtility.MESSAGE_API);
}