如何从我的活动中调用方法到我的片段适配器？我在我的片段上使用 RecyclerView ，并且在此片段适配器中有意图。我已经在我的主要活动中创建了一个方法，但是我无法从我的片段适配器中调用它。
主要活动中的方法
public void showInterstitial() {
if(interstitialAd != null && interstitialAd.isLoaded()) {
interstitialAd.show();
loadingIklan=true;
}
}
我希望将该方法放在片段适配器
上的意图切换案例中 public class HomeAdapter extends RecyclerView.Adapter<HomeAdapter.ViewHolder> {
public static class ViewHolder extends RecyclerView.ViewHolder {
private TextView homeTitle;
private Context context;
public ViewHolder(View itemView) {
super(itemView);
context = itemView.getContext();
homeTitle = (TextView)itemView.findViewById(R.id.homeTitle);
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
final Intent intent;
switch (getAdapterPosition()) {
case 0:
((MainActivity) getActivity()).showInterstitial();
intent = new Intent(context, AllBlock.class);
break;
case 1:
intent = new Intent(context, BasicBlock.class);
break;
default:
intent = new Intent(context, AllBlock.class);
break;
}
context.startActivity(intent);
}
});
}
}
public List<HomeData> homeList;
public HomeAdapter(List<HomeData> homeList) {
this.homeList = homeList;
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.home_item, parent, false);
ViewHolder viewHolder = new ViewHolder(view);
return viewHolder;
}
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
holder.homeTitle.setText(homeList.get(position).getHomeTitle());
}
@Override
public int getItemCount() {
return homeList.size();
}
}
我的主要片段
public class Home extends Fragment {
public Home() {
// Required empty public constructor
}
private RecyclerView recyclerView;
private HomeAdapter homeAdapter;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.home, container, false);
recyclerView = (RecyclerView)view.findViewById(R.id.recyclerview);
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getActivity());
recyclerView.setLayoutManager(layoutManager);
homeAdapter = new HomeAdapter(homeDataList());
recyclerView.setAdapter(homeAdapter);
return view;
}
}
任何人都可以用正确的代码帮助我吗？谢谢。
答案 0 :(得分：1)
您不应该从RecyclerView适配器调用活动。适配器应该只处理数据显示。因此，您需要一个Listener / Callback模式。因为您的适配器是从片段调用的，其中片段附加到活动，所以您需要创建一个嵌套的Listener / Callback。
首先，在RecyclerView适配器中创建侦听器接口。接口的目的是告诉监听器（Fragment）做某事。
public class YourAdapter extends RecyclerView.Adapter<YourAdapter.ViewHolder> {
...
private AdapterListener listener;
// define the listener
public interface AdapterListener {
void onItemClicked(int position);
}
// register the listener with this method
public setListener(AdapterListener listener) {
this.listener = listener;
}
...
public ViewHolder(View itemView) {
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// tell the listener about the click
if(listener != null) {
listener.onItemClicked(getAdapterPosition());
}
}
}
}
第二次，将片段注册为侦听器：
public class YourFragment extends Fragment {
...
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
...
// This is an example, you can register the listener in any method
// sample
YourAdapter adapter = new YourAdapter(...);
YourAdapter.AdapterListener listener = new YourAdapter.AdapterListener {
@Override
public void onItemClicked(int position) {
// handle the item click here.
}
}
}
}
第三次，创建侦听器以在片段和活动之间进行通信（在Communicating with Other Fragments阅读更多内容：
public class YourFragment extends Fragment {
private FragmentListener mListener;
public interface FragmentListener {
onRecyclerViewItemClicked(int position);
}
@Override
public void onAttach(Context context) {
super.onAttach(context);
// This makes sure that the container activity has implemented
// the callback interface. If not, it throws an exception
try {
mCallback = (FragmentListener) context;
} catch (ClassCastException e) {
throw new ClassCastException(context.toString()
+ " must implement FragmentListener");
}
}
}
第四，执行片段监听器，告诉活动有关recyclelerView项目的点击。在以前的Adapter侦听器中添加代码：
public class YourFragment extends Fragment {
...
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
...
// This is an example, you can register the listener in any method
YourAdapter adapter = new YourAdapter(...);
YourAdapter.AdapterListener listener = new YourAdapter.AdapterListener {
@Override
public void onItemClicked(int position) {
mListener.onRecyclerViewItemClicked(position);
}
}
}
}
第五，将活动注册为侦听接收者。因此，你做了实际的逻辑：
public class YourActivity extends Activity
implements YourFragment.FragmentListener {
...
@Ovveride
public void onRecyclerViewItemClicked(int position) {
// Handle the RecyclerView item click here
switch(position) {
case 0:
showInterstitial();
break;
default:
intent = new Intent(this, AllBlock.class);
startActivity(intent);
}
}
}
注意：
我倾向于将事件总线机制与EventBus一起使用，因为它简化了所有侦听器代码。在掌握了监听器/回调模式后，您可以尝试使用EventBus。的 Horas！
答案 1 :(得分：0)
interfacesample.java
public interface sample{
function onclick();
}
activity.java
class activity extends appcombatactivity implements sample{
override onclick(){
//do whatever you want to do
}
}
// adapter.java
switch (getAdapterPosition()) {
case 0:
//getActivity show red code//
(context as activity).onclick()
break;
default:
intent = new Intent(context, AllBlock.class);
break;
}