Java 无法从内部片段刷新RecycleVew？

我在片段中显示数据起初我在Create View上使用了函数中的一些函数，一切都变得完美，成功地获取和显示了数据，但是当我从另一个函数中调用adpter尝试重新显示和更新数据时，出现了错误， 具体来说，当我按下对话框内的按钮时，会出现问题， 请帮忙

    //CustomerAdapter class 
    public class CustomerAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

        public final int TYPE_MOVIE = 0;
        public final int TYPE_LOAD = 1;

        static Context context;
        List<Customer>customers;
        OnLoadMoreListener loadMoreListener;
        boolean isLoading = false, isMoreDataAvailable = true;

        public CustomerAdapter(Context context, List<Customer> customers) {
            this.context = context;
            this.customers = customers;
        }

        public void refreshEvents(List<Customer> data) {
            clear();
            addAll(data);
            notifyDataSetChanged();
        }



        @Override
        public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

            LayoutInflater inflater = LayoutInflater.from(context);
            if(viewType==TYPE_MOVIE){
                return new CustomerHolder(inflater.inflate(R.layout.row_movie,parent,false));
            }else{
                return new LoadHolder(inflater.inflate(R.layout.row_load,parent,false));
            }
        }


        @Override
        public void onBindViewHolder(final RecyclerView.ViewHolder holder, final int position) {

            if(position>=getItemCount()-1 && isMoreDataAvailable && !isLoading && loadMoreListener!=null){
                isLoading = true;
                loadMoreListener.onLoadMore();
            }


            if(getItemViewType(position)==TYPE_MOVIE){
                ((CustomerHolder)holder).bindData(customers.get(position));

                if(((CustomerHolder)holder).buttonViewOption != null)((CustomerHolder)holder).buttonViewOption.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {
                  //  function call a volly function .. //..
                  // if(customers.get(position).user_id==2)((CustomerHolder)holder).imgLock.setVisibility(View.VISIBLE);
                  ((CustomerHolder)holder).buttonViewOption.getRootView().toString();
               //    Toast.makeText(context,"Index Is "+customers.get(position).status+"usr_id"+customers.get(position).user_id, Toast.LENGTH_SHORT).show();
                    //Page_6Fragment.newInstance().sendNotfic(context ,customers.get(position).user_id);
                       // Call a fucntion to
                  Page_6Fragment.newInstance().showDialog(context,customers.get(position).user_id , Integer.parseInt(customers.get(position).id));
                    }
                });
            }
        }


        @Override
        public int getItemViewType(int position) {

            if(customers.get(position).type.equals("movie")){
                return TYPE_MOVIE;
            }else{
                return TYPE_LOAD;
            }
        }


        @Override
        public int getItemCount(){

           return customers.size();
        }

        /* VIEW HOLDERS */

        static class CustomerHolder extends RecyclerView.ViewHolder{
            TextView tvTitle;
            TextView tvRating;
            ImageView imgLock;
            //  int usrid;

            Button buttonViewOption;

            public CustomerHolder(View itemView){
                super(itemView);
                tvTitle=(TextView)itemView.findViewById(R.id.title);
                tvRating=(TextView)itemView.findViewById(R.id.rating);
                imgLock=(ImageView)itemView.findViewById(R.id.img_lock);
                buttonViewOption = (Button) itemView.findViewById(R.id.textViewOptions);
            }


            void bindData(Customer cust){
               tvTitle.setText(cust.name);
               tvRating.setText(cust.title);
               // if(cust.user_id==2)imgLock.setVisibility(View.GONE);
                if(cust.status!=0)buttonViewOption.setBackground(context.getResources().getDrawable(R.drawable.lock));
                //  imgLock.setVisibility(View.VISIBLE);
            }
        }


        static class LoadHolder extends RecyclerView.ViewHolder{

            public LoadHolder(View itemView){
                super(itemView);
            }
        }

        public void setMoreDataAvailable(boolean moreDataAvailable) {
            isMoreDataAvailable = moreDataAvailable;
        }

        /* notifyDataSetChanged is final method so we can't override it
             call adapter.notifyDataChanged(); after update the list
        */

        public void notifyDataChanged(){
            notifyDataSetChanged();
            isLoading = false;
        }
        public interface OnLoadMoreListener{
            void onLoadMore();
        }


        public void setLoadMoreListener(OnLoadMoreListener loadMoreListener) {
            this.loadMoreListener = loadMoreListener;
        }
    }


    // Fragment class : 
    public class Page_6Fragment extends android.support.v4.app.Fragment implements AdapterView.OnItemSelectedListener {
        TextView t1,t2,t3,t4;
        Spinner spin,spin2,spin3,spin4;
        Dialog dialog;
        RecyclerView recyclerView;
        List<Customer>customers;
        CustomerAdapter adapter;
        View rootView;
        String TAG = "MainActivity - ";
        Context context;
        API api;
        Activity a;
        Boolean acceptOrNo = true;
        Context c =null;

        public static Page_6Fragment newInstance(){

            Page_6Fragment fragment = new Page_6Fragment();

            return fragment;
        }


        @Override
        public void onCreate(Bundle savedInstanceState) {

            super.onCreate(savedInstanceState);

        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            rootView = inflater.inflate(R.layout.activity_customer, container, false);
            //View rootView = inflater.inflate(R.xml.pref, container, false);
            //Intent intent = new Intent(PreferenceDemoActivity.this,PrefsActivity.class);
            // startActivity(intent);
            this.context = getActivity();
            recyclerView = (RecyclerView) rootView.findViewById(R.id.recycler_view);
            customers = new ArrayList<>();
            adapter = new CustomerAdapter(context,customers);
            adapter.setLoadMoreListener(new CustomerAdapter.OnLoadMoreListener(){
                @Override
                public void onLoadMore() {
                    recyclerView.post(new Runnable() {
                        @Override
                        public void run() {
                            int index = customers.size();
                          loadMore(index);
                        }
                    });
                    //Calling loadMore function in Runnable to fix the
                    // java.lang.IllegalStateException: Cannot call this method while RecyclerView is computing a layout or scrolling error
                }
            });
            recyclerView.setHasFixedSize(true);
            recyclerView.setLayoutManager(new LinearLayoutManager(context));
            recyclerView.setAdapter(adapter);
            api = ServiceGenerator.createService(API.class);
            load(0);
          return rootView;
        }


    //  recyclerView.addItemDecoration(new VerticalLineDecorator(2));

        private void load(int index){

            Call<List<Customer>> call = api.getCustomer(index);
            call.enqueue(new Callback<List<Customer>>(){
                @Override
                public void onResponse(Call<List<Customer>> call, final Response<List<Customer>> response){
                    // Toast.makeText(MainActivity.this, "tost "+response.body().get(0).post_writer, Toast.LENGTH_LONG).show();
                   //Log.i("TRUE_TRUE_","Yes "+response.body().get(2).name);
                    if(response.isSuccessful()){
                     //Log.i("TRUE_TRUE3","Yes"+response.body().toString());
                     //movies.addAll(response.body());
                     //adapter.notifyDataChanged();
                     getActivity().runOnUiThread(new Runnable(){
                     public void run(){
                      // No.1 ..............
                      // ShowDataScreen();
                       // Toast.makeText( MainActivity.this, "ShowDataScreen",Toast.LENGTH_SHORT).show();
                           customers.addAll(response.body());
                            adapter.notifyDataChanged();
                             }});// end of No.1 UI new thread
                            getActivity().runOnUiThread(new Runnable(){
                            public void run() {//No.2
                               // Toast.makeText( MainActivity.this, "This is correct way",Toast.LENGTH_SHORT).show();
                            }});// end of No.2 UI new thread
                          // Toast.makeText(MainActivity.this, "tost "+response.body().get(0).post_writer, Toast.LENGTH_LONG).show();
                    }else{
                        Log.e(TAG," Response Error "+String.valueOf(response.code()));
                    }
                }
                @Override
                public void onFailure(Call<List<Customer>> call, Throwable t) {
                    Log.e(TAG," Response Error "+t.getMessage());
                }
            });
        }


        public void showDialog(final Context context , final int getToken , final int id){
            dialog = new Dialog(context);
            dialog.setCancelable(true);
            // dialog.setTitle("استقبال الطلب");
            dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
            dialog.setContentView(R.layout.layout);
            dialog.show();
            String[] bankNames = {
                    "O","B","H","N","j"
            };
            t1= (TextView)dialog.findViewById(R.id.tv_h);
            t2= (TextView)dialog.findViewById(R.id.tv_m);
            t3= (TextView)dialog.findViewById(R.id.tv_title);
            t4= (TextView)dialog.findViewById(R.id.tv_pam);
            spin =(Spinner)dialog.findViewById(R.id.spinner_minutes);
            spin2 =(Spinner)dialog.findViewById(R.id.spinner_minutes2);
            spin3 =(Spinner)dialog.findViewById(R.id.spinner_minutes3);
            spin4 =(Spinner)dialog.findViewById(R.id.tex);
            spin.setOnItemSelectedListener(this);
            spin2.setOnItemSelectedListener(this);
            spin3.setOnItemSelectedListener(this);
            spin4.setOnItemSelectedListener(this);
            RadioButton radioButton2 = (RadioButton)dialog.findViewById(R.id.second2);
            RadioButton radioButton = (RadioButton)dialog.findViewById(R.id.second);
            RadioGroup radioGroup = (RadioGroup)dialog.findViewById(R.id.radioSex);
            ArrayAdapter<String> a = new ArrayAdapter<String>(context,R.layout.spinner_item,bankNames);
            //ArrayAdapter b = new ArrayAdapter(this,android.R.layout.simple_spinner_item,bankNames2);
            //a.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
            //spin.setAdapter(a);
            radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
                @Override
                public void onCheckedChanged(RadioGroup group, int checkedId) {
                    RadioButton radioButton = (RadioButton)dialog.findViewById(checkedId);
                    if (checkedId == R.id.second2) {
                       RadioYes();
                       acceptOrNo = false;
                    } else if (checkedId == R.id.second) {
                       acceptOrNo = true;
                       RadioNo();
                 }
                }
            });


            Button btnOk = (Button)dialog.findViewById(R.id.button_cancel);
            btnOk.setOnClickListener(new View.OnClickListener(){
                public void onClick(View v) {
            //TODO Auto-generated method stub
            // Log.i("trace_u",""+acceptOrNo);
            if(acceptOrNo)sendNotfic(context , id , getToken ,"1" , spin4.getSelectedItem().toString() ,  "الساعه"+spin.getSelectedItem().toString()+":"+spin2.getSelectedItem().toString()+" "+spin3.getSelectedItem().toString());
            else
            sendNotfic(context , id , getToken ,"2","--" ,"--");
            dialog.dismiss();

                    /// Update Rview
                   // if(adapter != null) {
                       adapter.refreshEvents(customers);
                    //}

                }
            });


            Button btnNo = (Button)dialog.findViewById(R.id.button_set);
            btnNo.setOnClickListener(new View.OnClickListener(){
                public void onClick(View v) {
            // TODO Auto-generated method stub
                    dialog.dismiss();
                    /*
                    adapter = new CustomerAdapter(context , customers);
                    Log.i("adapter_",""+adapter);
                    if(adapter != null) {
                        Log.i("adpter_33","yesysy");
                        adapter.refreshEvents();
                    }
    */
              }
            });
        }

// Loge cat : 

 Process: com.example.android.wacher, PID: 2519
                                                                          java.lang.NullPointerException: Attempt to invoke virtual method 'void com.example.android.wacher.adapters.CustomerAdapter.refreshEvents(java.util.List)' on a null object reference
                                                                              at com.example.android.wacher.fragments.Page_6Fragment$8.onClick(Page_6Fragment.java:312)
                                                                              at android.view.View.performClick(View.java:5609)
                                                                              at android.view.View$PerformClick.run(View.java:22259)
                                                                              at android.os.Handler.handleCallback(Handler.java:751)
                                                                              at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                              at android.os.Looper.loop(Looper.java:154)
                                                                              at android.app.ActivityThread.main(ActivityThread.java:6077)
                                                                              at java.lang.reflect.Method.invoke(Native Method)
                                                                              at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
                                                                              at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)

//CustomerAdapter类
公共类CustomerAdapter扩展了RecyclerView.Adapter{
公共最终整型电影=0；
公共最终整型负荷=1；
静态语境；
列出客户；
OnLoadMoreListener加载MoreListener；
布尔isLoading=false，isMoreDataAvailable=true；
公共CustomerAdapter（上下文，列出客户）{
this.context=上下文；
这是。顾客=顾客；
}
公共事件（列表数据）{
清除（）；
addAll（数据）；
notifyDataSetChanged（）；
}
@凌驾
public RecyclerView.ViewHolder onCreateViewHolder（视图组父级，int-viewType）{
LayoutFlater充气机=LayoutFlater.from（上下文）；
if（viewType==类型\电影）{
返回新的CustomerHolder（充气器。充气（R.layout.row_movie，父项，false））；
}否则{
返回新的装载架（充气机。充气（右布局。第_行装载，父项，错误））；
}
}
@凌驾
公共无效onBindViewHolder（最终RecyclerView.ViewHolder，最终整型位置）{
如果（位置>=getItemCount（）-1&&isMoreDataAvailable&&isLoading&&loadMoreListener！=null）{
isLoading=true；
loadMoreListener.onLoadMore（）；
}
if（getItemViewType（position）=类型\u电影）{
（（CustomerHolder）holder.bindData（customers.get（position））；
if（（（CustomerHolder）holder）.buttonViewOption！=null）（（CustomerHolder）holder.buttonViewOption.setOnClickListener（新视图.OnClickListener（））{
@凌驾
公共void onClick（视图）{
//函数调用volly函数../。。
//if（customers.get（position）.user_id==2）（CustomerHolder）holder.imgLock.setVisibility（View.VISIBLE）；
（（CustomerHolder）holder.buttonViewOption.getRootView（）.toString（）；
//Toast.makeText（上下文，“索引为”+customers.get（position）.status+“usr_id”+customers.get（position）.user_id，Toast.LENGTH_SHORT.show（）；
//Page_6Fragment.newInstance（）.sendNotfic（上下文，customers.get（position）.user_id）；
//打电话给某人
Page_6Fragment.newInstance（）.showDialog（上下文，customers.get（position）.user_id，Integer.parseInt（customers.get（position）.id））；
}
});
}
}
@凌驾
public int getItemViewType（int位置）{
if（customers.get（position）.type.equals（“电影”））{
返回式电影；
}否则{
返回式负载；
}
}
@凌驾
public int getItemCount（）{
返回客户。size（）；
}
/*视图持有者*/
静态类CustomerHolder扩展了RecyclerView.ViewHolder{
文本视图标题；
文本视图电视收视率；
ImageView-imgLock；
//内乌斯里德；
按钮查看选项；
公共CustomerHolder（查看项目视图）{
超级（项目视图）；
tvTitle=（TextView）itemView.findViewById（R.id.title）；
tvRating=（TextView）itemView.findViewById（R.id.rating）；
imgLock=（ImageView）itemView.findViewById（R.id.img_lock）；
buttonViewOption=（按钮）itemView.findViewById（R.id.textViewOptions）；
}
作废数据（客户客户）{
tvTitle.setText（客户名称）；
tvRating.setText（客户名称）；
//if（cust.user_id==2）imgLock.setVisibility（View.GONE）；
if（cust.status！=0）按钮查看选项.setBackground（context.getResources（）.getDrawable（R.drawable.lock））；
//imgLock.setVisibility（View.VISIBLE）；
}
}
静态类LoadHolder扩展了RecyclerView.ViewHolder{
公共装载机（查看项目视图）{
超级（项目视图）；
}
}
public void setMoreDataAvailable（布尔moreDataAvailable）{
isMoreDataAvailable=更多数据可用；
}
/*notifyDataSetChanged是最终方法，因此无法重写它
更新列表后调用adapter.notifyDataChanged（）
*/
public void notifyDataChanged（）{
notifyDataSetChanged（）；
isLoading=false；
}
公共接口OnLoadMoreListener{
void onload more（）；
}
public void setLoadMoreListener（OnLoadMoreListener loadMoreListener）{
this.loadMoreListener=loadMoreListener；
}
}
//片段类：
公共类页面_6Fragment扩展了android.support.v4.app.Fragment实现了AdapterView.OnItemSelectedListener{
文本视图t1、t2、t3、t4；
旋转器旋转，旋转2，旋转3，旋转4；
对话；
回收视图回收视图；
列出客户；
客户适配器；
视图根视图；
String TAG=“MainActivity-”；
语境；
API；
活动a；
布尔值acceptOrNo=true；
上下文c=null；
公共静态页面_6Fragment newInstance（）{
Page_6Fragment fragment=新的Page_6Fragment（）；
返回片段；
}
@凌驾
创建时的公共void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
}
Page_6Fragment.newInstance().showDialog(context,customers.get(position).user_id , Integer.parseInt(customers.get(position).id));

public CustomerAdapter(Page_6Fragment page_6Fragment, List<Customer> customers) {
    // You can get context from page_6Fragment.getContext()
    // And No need to make the context or the fragment static
}

page_6Fragment.showDialog(context,customers.get(position).user_id , Integer.parseInt(customers.get(position).id));

adapter = new CustomerAdapter(Page_6Fragment.this,customers);