Java 从列表中选择项目时，该项目不会显示在textview（EditorFragment）中

EditorFragment，textview:onclick，dialogfragment将打开， dialogfragment，两部分：a）搜索字段b）回收视图。 适配器，它处理列表中的项选择

EditorFragment代码：在EditorFragment中，选中项目后，该项目将显示在textview中

    public class EditorFragment extends Fragment {

    public static TextView tv_custom_spinner;
    private Context context;
    SearchAdapter searchAdapter = null;
    List<SearchModel> searchModelList ;


    public EditorFragment(Context context) {
        this.context = context;
        // Required empty public constructor
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_blank, container, false);
        searchModelList = new ArrayList<>();
        searchModelList.add(new SearchModel("First Name"));
        searchModelList.add(new SearchModel("Second Name"));
        searchModelList.add(new SearchModel("Third Name"));
        searchModelList.add(new SearchModel("Fourth Name"));
        searchModelList.add(new SearchModel("Fifth Name"));
        searchModelList.add(new SearchModel("Sixth Name"));

        searchAdapter = new SearchAdapter(context,searchModelList);

        setResources(view);
        clickSpinner();
        return view;
    }

    private void setResources(View view){
        tv_custom_spinner = view.findViewById(R.id.tv_custom_spinner);
    }

    private void clickSpinner(){
        tv_custom_spinner.setOnClickListener(v->{
            FragmentManager fragmentManager = getActivity().getSupportFragmentManager();
            SpinnerDialogfragment spinnerDialogFragment= new  SpinnerDialogfragment(context, searchModelList);

            spinnerDialogFragment.show(fragmentManager, "SPINNER");
        });

        searchAdapter.setUpdateDataListener(value -> tv_custom_spinner.setText(value));
    }
}

---

进程25724已终止。

在

onViewCreated

方法中初始化此

DataListener

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_blank, container, false);
    searchModelList = new ArrayList<>();
    searchModelList.add(new SearchModel("First Name"));
    searchModelList.add(new SearchModel("Second Name"));
    searchModelList.add(new SearchModel("Third Name"));
    searchModelList.add(new SearchModel("Fourth Name"));
    searchModelList.add(new SearchModel("Fifth Name"));
    searchModelList.add(new SearchModel("Sixth Name"));

    searchAdapter = new SearchAdapter(context,searchModelList);

    //Initialise  DataListener here
    searchAdapter.setUpdateDataListener(new UpdateDataListener() {
        @Override
        public void onItemSelected(String value) {
            tv_custom_spinner.setText(value);
        }
    });

    setResources(view);
    clickSpinner();
    return view;
}

@覆盖
创建视图上的公共视图（布局、充气机、视图组容器、，
Bundle savedInstanceState）{
//为该碎片膨胀布局
视图=充气机。充气（R.layout.fragment\u blank，container，false）；
searchModelList=新的ArrayList（）；
添加（新的SearchModel（“名字”））；
添加（新的SearchModel（“第二个名称”）；
添加（新的SearchModel（“第三个名称”）；
添加（新的SearchModel（“第四个名称”）；
添加（新的SearchModel（“第五个名称”）；
添加（新的SearchModel（“第六个名称”）；
searchAdapter=新的searchAdapter（上下文，searchModelList）；
//在此处初始化DataListener
setUpdateDataListener（新的UpdateDataListener（）{
@凌驾
已选择公共值（字符串值）{
tv_custom_spinner.setText（值）；
}
});
设置资源（视图）；
单击微调器（）；
返回视图；
}

在片段onviewcreated（）调用中

---

然后再试一次。空期望值应该消失并且应该可以工作

如果您的侦听器为空，请尝试在activity/fragmentUpdated中设置/更新，您永远不会创建UpdateDataStenerSearchAdapter.setUpdateDataListener（新的SearchAdapter.UpdateDataListener（）{@Override public void onItemSelected（字符串值）{tv_custom_spinner.setText（value）；}}}）；当使用lambda时，此时无需创建updateDataListener（），是否需要推送“SpinnerDialogfragment.java”的代码？？

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.coco.myapplication, PID: 25724
    java.lang.NullPointerException: Attempt to invoke interface method 'void com.coco.myapplication.SearchAdapter$UpdateDataListner.onItemSelected(java.lang.String)' on a null object reference
        at com.coco.myapplication.SearchAdapter.lambda$onBindViewHolder$0$SearchAdapter(SearchAdapter.java:53)
        at com.coco.myapplication.-$$Lambda$SearchAdapter$fc2DFbNCnzN7ljubXWaQ4mEoai8.onClick(Unknown Source:4)
        at android.view.View.performClick(View.java:6608)
        at android.view.View.performClickInternal(View.java:6585)
        at android.view.View.access$3100(View.java:782)
        at android.view.View$PerformClick.run(View.java:25945)
        at android.os.Handler.handleCallback(Handler.java:874)
        at android.os.Handler.dispatchMessage(Handler.java:100)
        at android.os.Looper.loop(Looper.java:198)
        at android.app.ActivityThread.main(ActivityThread.java:6729)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_blank, container, false);
    searchModelList = new ArrayList<>();
    searchModelList.add(new SearchModel("First Name"));
    searchModelList.add(new SearchModel("Second Name"));
    searchModelList.add(new SearchModel("Third Name"));
    searchModelList.add(new SearchModel("Fourth Name"));
    searchModelList.add(new SearchModel("Fifth Name"));
    searchModelList.add(new SearchModel("Sixth Name"));

    searchAdapter = new SearchAdapter(context,searchModelList);

    //Initialise  DataListener here
    searchAdapter.setUpdateDataListener(new UpdateDataListener() {
        @Override
        public void onItemSelected(String value) {
            tv_custom_spinner.setText(value);
        }
    });

    setResources(view);
    clickSpinner();
    return view;
}

setUpdateDataListener("pass your listner")