Question

我的一个碎片中有一个按钮。但它似乎是“不可点击”。没有Log.d.单击按钮时的消息（在另一个片段（相同的onclicklistenercode）中一切都很好。为了更好的概述，我添加了整个类和布局文件的一部分，用于定义按钮。

public class ListViewFragment extends Fragment {

    DbHelper mydb;

    Button buttondeletedb;
    Button buttonexport;

    private EditText roomnr;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_listview, container, false);

        Context context = getContext();
        mydb = new DbHelper(context);

        buttondeletedb = (Button) view.findViewById(R.id.button_deletelist_list);
        buttonexport = (Button) view.findViewById(R.id.button_export);

        String dataList = mydb.getAllElements();                                                   
        String [] dataListArray = dataList.split("\n");                                             

        List<String> dataListFinal = new ArrayList<>(Arrays.asList(dataListArray));

        ArrayAdapter<String> dataListAdapter = new ArrayAdapter<>(                                  
                getActivity(),                                                                      
                R.layout.list_item_datalist,                                                        
                R.id.list_item_datalist_textview,                                                   
                dataListFinal);                                                                     

        View rootView=inflater.inflate(R.layout.fragment_listview, container, false);

        ListView dataListListView = (ListView) rootView.findViewById(R.id.datalist);
        dataListListView.setAdapter(dataListAdapter);


        buttondeletedb.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Log.d("buttondeletelist", "clicked!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!");
                mydb.deleteAll();
            }
        });

        return rootView;
    }


}

            <Button
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@string/deletelist"
                android:id="@+id/button_deletelist_list"
                android:layout_gravity="center_horizontal" />

Answer 1

您无法点击该按钮，因为片段的根视图不是视图，您返回 rootView 。该按钮是视图的子视图。

将return rootView;更改为return view;。

应该有效

Answer 2

//删除rootView并返回视图而不是rootView

public class ListViewFragment extends Fragment {

                DbHelper mydb;

                Button buttondeletedb;
                Button buttonexport;

                private EditText roomnr;

                @Override
                public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
                    View view = inflater.inflate(R.layout.fragment_listview, container, false);

                    Context context = getContext();
                    mydb = new DbHelper(context);

                    buttondeletedb = (Button) view.findViewById(R.id.button_deletelist_list);
                    buttonexport = (Button) view.findViewById(R.id.button_export);

                    String dataList = mydb.getAllElements();                                                   
                    String [] dataListArray = dataList.split("\n");                                             

                    List<String> dataListFinal = new ArrayList<>(Arrays.asList(dataListArray));

                    ArrayAdapter<String> dataListAdapter = new ArrayAdapter<>(                                  
                            getActivity(),                                                                      
                            R.layout.list_item_datalist,                                                        
                            R.id.list_item_datalist_textview,                                                   
                            dataListFinal);                                                                     
            // Change made here. replace view instead of rootView and remove rootView
                    ListView dataListListView = (ListView) view.findViewById(R.id.datalist);
                    dataListListView.setAdapter(dataListAdapter);


                    buttondeletedb.setOnClickListener(new View.OnClickListener() {
                        @Override
                        public void onClick(View view) {
                            Log.d("buttondeletelist", "clicked!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!");
                            mydb.deleteAll();
                        }
                    });
            // Replace rootView with view.
                    return view;
                }


            }

Answer 3

XML文件和Element（Button）的Class文件之间的链接不存在。在onCreateView（）

中添加这一行

   Button buttondeletedb = (Button) view.findViewById(R.id.buttonid);

按钮没有响应

3 个答案: