Question

我正在尝试初始化片段中的下拉列表。我收到以下错误。构造函数ArrayAdapter（FragTasbeeh，int，String []）未定义你也可以解释一下如何在片段中使用活动类，因为一次只能扩展一个类。

{
    public class FragTasbeeh extends Fragment {

        ImageView ivIcon;
        TextView tvItemName;
        Button add;
        int counter = 0;


        public static final String IMAGE_RESOURCE_ID = "iconResourceID";
        public static final String ITEM_NAME = "itemName";


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

            View view = inflater.inflate(R.layout.tasbeeh, container, false);
            if (savedInstanceState == null) {
                counter = 0;
            } else {
                counter = savedInstanceState.getInt("counter", 0);
            }

            return view;

        }


        @
        Override
        public void onActivityCreated(Bundle savedInstanceState) {
            // TODO Auto-generated method stub
            super.onActivityCreated(savedInstanceState);
            add = (Button) getActivity().findViewById(R.id.button1);
            tvItemName = (TextView) getActivity().findViewById(R.id.textView1);
            add.setOnClickListener(new View.OnClickListener() {

                @
                Override
                public void onClick(View v) {
                    // TODO Auto-generated method stub
                    counter++;
                    tvItemName.setText(counter + "");
                }
            });
        }

        private Spinner spinner;
        public static final String[] items = {
            "1", "2", "3"
        };

        @
        Override
        public void onCreate(Bundle savedInstanceState) {
            // TODO Auto-generated method stub
            super.onCreate(savedInstanceState);
            Spinner dropdown = (Spinner) getActivity().findViewById(R.id.spin);
            String[] items = new String[] {
                "1", "2", "three"
            };
            ArrayAdapter < String > adapter = new ArrayAdapter < String > (this, android.R.layout.simple_spinner_item, items);
            dropdown.setAdapter(adapter);
        }

    }
}

Answer 1

而不是

 ArrayAdapter < String > adapter = 
   new ArrayAdapter < String > (this, android.R.layout.simple_spinner_item, items);

尝试

  ArrayAdapter < String > adapter = 
   new ArrayAdapter < String > (getActivity(), android.R.layout.simple_spinner_item, items);

Answer 2

而不是传递给

ArrayAdapter < String > adapter = new ArrayAdapter < String > (this, android.R.layout.simple_spinner_item, items);

传递this.getActivity（），如下所示

ArrayAdapter < String > adapter = new ArrayAdapter < String > (this.getActivity(), android.R.layout.simple_spinner_item, items);

Answer 3

不要将this用作ArrayAdapter的第一个参数。

此处this是您的片段FragTasbeeh。

所以这意味着 -

The constructor ArrayAdapter<String>(FragTasbeeh , int, String[]) is undefined.

您需要使用以下ArrayAdapter -

public ArrayAdapter （上下文上下文，int资源，T []对象）

<强>参数

context 当前上下文。

resource 包含在实例化视图时使用的TextView的布局文件的资源ID。

objects 要在ListView中表示的对象。

只需将行更改为 -

    ArrayAdapter<String> adapter = new ArrayAdapter <String> (getActivity(),
    android.R.layout.simple_spinner_item, items);

或

ArrayAdapter<String> adapter = new ArrayAdapter< String>(this.getActivity(), android.R.layout.simple_spinner_item, items);

在ArrayAdapter中使用spinner进行碎片错误是未定义的

3 个答案: