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Java 将项目添加到片段中的ListView中_Java_Android_Android Studio_Android Fragments - Fatal编程技术网

Java 将项目添加到片段中的ListView中

Java 将项目添加到片段中的ListView中,java,android,android-studio,android-fragments,Java,Android,Android Studio,Android Fragments,我想通过editText在ListView中添加项,但当我运行代码时,它不起作用 public class EventosFragment extends Fragment { private ListView lista; private Button boton; EditText editText; ArrayList<String> arrayList; ArrayAdapter<String> adapter; public View onCreateView

我想通过editText在ListView中添加项,但当我运行代码时,它不起作用

public class EventosFragment extends Fragment {
private ListView lista;
private Button boton;
EditText editText;
ArrayList<String> arrayList;
ArrayAdapter<String> adapter;

public View onCreateView(@NonNull LayoutInflater inflater,
                         ViewGroup container, Bundle savedInstanceState) {

    View view = inflater.inflate(R.layout.fragment_eventos, container, false);

    String[] Lista = {};
    ListView listView = (ListView) view.findViewById(R.id.Lista);
    arrayList = new ArrayList<>(Arrays.asList(Lista));
    adapter = new ArrayAdapter<String>(getActivity(),android.R.layout.simple_list_item_1,arrayList);
    listView.setAdapter(adapter);

    editText = (EditText) view.findViewById(R.id.edittxt);
    Button btnAdd = (Button) view.findViewById(R.id.Aceptar);
    btnAdd.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String Aceptar = editText.getText().toString();
            arrayList.add(Aceptar);
        }
    });

    return view;
}
}
public类EventosFragment扩展了片段{
私有ListView lista;
私人按钮按钮;
编辑文本编辑文本;
ArrayList ArrayList;
阵列适配器;
公共视图onCreateView(@NonNull layoutiner充气机,
视图组容器,捆绑包savedInstanceState){
视图=充气机。充气(R.layout.fragment\u events,container,false);
字符串[]Lista={};
ListView=(ListView)view.findViewById(R.id.Lista);
arrayList=新的arrayList(Arrays.asList(Lista));
adapter=newArrayAdapter(getActivity(),android.R.layout.simple\u list\u item\u 1,arrayList);
setAdapter(适配器);
editText=(editText)view.findViewById(R.id.edittxt);
按钮btnAdd=(按钮)视图.findViewById(R.id.Aceptar);
btnAdd.setOnClickListener(新视图.OnClickListener(){
@凌驾
公共void onClick(视图v){
字符串Aceptar=editText.getText().toString();
arrayList.add(Aceptar);
}
});
返回视图;
}
}
任何建议都行,我是Java新手,谢谢。

在将项添加到arraylist后使用适配器的notifyDataSetChanged()方法

btnAdd.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String Aceptar = editText.getText().toString();
            arrayList.add(Aceptar);
            adapter.notifyDataSetChanged();
        }
    });

希望这会有帮助

只需在
onclick
方法中添加
notifyDataSetChanged
。您的数据已成功添加到arraylist中,但您的适配器不知道您已通知适配器。就这样

 arrayList.add(Aceptar);
 //this will notify the adapter whole is changed
 adapter.notifyDataSetChanged();

作为适配器,这不是正确的答案。notifyItemInserted(arrayList.size()-1)不是ArrayAdapter的方法,请再次检查。@NehalGodhasara您在发布的答案中也做了同样的事情。我想您没有注意到这个答案稍后会被编辑,我在这个答案之前发布了相同的答案。