Android Spinner 适配器和 Lollipop

Question

像许多其他人一样，我在我的 android 应用程序中使用 Parse.com。当我在 fragment 中使用 ParseQueryAdapter 来检索数据并将其传递给微调器 a

java.lang.IllegalArgumentException: Spinner adapter view type count must be 1

然后应用程序崩溃。

我已经搜索了修复程序，我知道这是 parse.com 而不是我必须解决的问题。但是，我真的想让我的应用看起来像 Material Design，如果我的应用 targetSdkVersion 19，状态栏总是黑色的。

这个问题有一个我不明白的答案，我不能直接在问题中提问，因为我没有权限。该社区的成员 suggest to extend the parseadapter and @override the getViewTypeCount with this code .我是 Android 的新手，我不知道如何正确遵循该建议。如果你们帮我解决这个问题，我将不胜感激。

更新:

我遵循 this answer 中的代码, 但错误提示 MyParseAdapter 没有类型参数。

你能解释一下我做错了什么吗？

谢谢

编辑:

public void addItemsOnSpinner (){

    // Instantiate a QueryFactory to define the ParseQuery to be used for fetching items in this
    // Adapter.
    MyParseAdapter.QueryFactory<ParseObject> factory =
            new MyParseAdapter.QueryFactory<ParseObject>() {
                public ParseQuery create() {
                    ParseQuery query = new ParseQuery("Books");
                    //query.whereEqualTo("activated", true);
                    query.orderByAscending("title");
                    return query;
                }
            };

    // Pass the factory into the ParseQueryAdapter's constructor.
    ParseQueryAdapter<ParseObject> adapter = new MyParseAdapter<ParseObject>(getActivity(), factory);


    adapter.setTextKey("title");


   /* // Perhaps set a callback to be fired upon successful loading of a new set of ParseObjects.
    adapter.addOnQueryLoadListener(new OnQueryLoadListener<ParseObject>() {
        public void onLoading() {
            // Trigger any "loading" UI
        }

        public void onLoaded(List<ParseObject> objects, ParseException e) {
            // Execute any post-loading logic, hide "loading" UI
        }
    });*/

    spinnerBook.setPopupBackgroundResource(R.drawable.spinner_style);
    spinnerBook.setAdapter(adapter);

    spinnerBook.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {

            Toast.makeText(parent.getContext(),
                    "OnItemSelectedListener : " + parent.getItemAtPosition(pos).toString(),
                    Toast.LENGTH_SHORT).show();


            // Log.d("test", spinnerBook.getSelectedItem().toString());
            // Log.d("test2", parent.getItemAtPosition(pos).toString());
            ParseObject item = (ParseObject) parent.getAdapter().getItem(pos);
            objectID = item.getObjectId().toString();

            //Log.d("test3",objectID);

            ParseQuery<ParseObject> query = ParseQuery.getQuery("Books");
            query.getInBackground(objectID, new GetCallback<ParseObject>() {
                public void done(ParseObject object, ParseException e) {
                    if (e == null) {
                        // object will be your game score
                        bookTitle = object.getString("title");
                        txtBookAuthor.setText(object.getString("author"));
                        txtBookISBN.setText(object.getString("isbn"));
                        //  category = object.getString("category");
                    } else {
                        // something went wrong
                    }
                }
            });
        }

        public void onNothingSelected(AdapterView<?> arg0) {

        }
    });

}

Answer 1

我是这样解决问题的

首先我创建了一个这样的新类

public class MyParseAdapter extends ParseQueryAdapter<ParseObject> {

    public MyParseAdapter(Context context, QueryFactory<ParseObject> clazz) {
        super(context, clazz);
    }

    @Override
    public int getViewTypeCount() {
        return 1;
    }
}

我用 MyParseAdapter 替换了每个 ParseQueryAdapter 甚至声明

试试这个

public void addItemsOnSpinner (){

    // Instantiate a QueryFactory to define the ParseQuery to be used for fetching items in this
    // Adapter.
    MyParseAdapter.QueryFactory<ParseObject> factory =
            new MyParseAdapter.QueryFactory<ParseObject>() {
                public ParseQuery create() {
                    ParseQuery query = new ParseQuery("Books");
                    //query.whereEqualTo("activated", true);
                    query.orderByAscending("title");
                    return query;
                }
            };

    // Pass the factory into the ParseQueryAdapter's constructor.
    MyParseAdapter adapter = new MyParseAdapter(getActivity(), factory);


    adapter.setTextKey("title");


   /* // Perhaps set a callback to be fired upon successful loading of a new set of ParseObjects.
    adapter.addOnQueryLoadListener(new OnQueryLoadListener<ParseObject>() {
        public void onLoading() {
            // Trigger any "loading" UI
        }

        public void onLoaded(List<ParseObject> objects, ParseException e) {
            // Execute any post-loading logic, hide "loading" UI
        }
    });*/

    spinnerBook.setPopupBackgroundResource(R.drawable.spinner_style);
    spinnerBook.setAdapter(adapter);

    spinnerBook.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {

            Toast.makeText(parent.getContext(),
                    "OnItemSelectedListener : " + parent.getItemAtPosition(pos).toString(),
                    Toast.LENGTH_SHORT).show();


            // Log.d("test", spinnerBook.getSelectedItem().toString());
            // Log.d("test2", parent.getItemAtPosition(pos).toString());
            ParseObject item = (ParseObject) parent.getAdapter().getItem(pos);
            objectID = item.getObjectId().toString();

            //Log.d("test3",objectID);

            ParseQuery<ParseObject> query = ParseQuery.getQuery("Books");
            query.getInBackground(objectID, new GetCallback<ParseObject>() {
                public void done(ParseObject object, ParseException e) {
                    if (e == null) {
                        // object will be your game score
                        bookTitle = object.getString("title");
                        txtBookAuthor.setText(object.getString("author"));
                        txtBookISBN.setText(object.getString("isbn"));
                        //  category = object.getString("category");
                    } else {
                        // something went wrong
                    }
                }
            });
        }

        public void onNothingSelected(AdapterView<?> arg0) {

        }
    });

}