為什么我得到的是“mergeCursor”對象而不是“字符串”？

Question

當我執行下面的代碼時，我想得到text="All" ，因為它的可見值是那個，但我一直都在得到

String text = "android.database.MergeCursor@88a4aaa"

編碼：

String[] from = new String[]{"type"};
        int[] to = new int[]{android.R.id.text1};
Cursor cursorTypes = coctelsOpenHelper.getTypes();
        //Add "All" option to the spinner
        MatrixCursor matrixCursor = new MatrixCursor(new String[] { "_id", "type"});
        matrixCursor.addRow(new Object[] { "0", getString(R.string.title_all_drinks) });

        MergeCursor mergeCursor = new MergeCursor(new Cursor[] { matrixCursor, cursorTypes });

        spinnerType = view.findViewById(R.id.spinnerDrinkType);
        adapter = new SimpleCursorAdapter(getContext(), android.R.layout.simple_spinner_item, mergeCursor, from, to,0);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinnerType.setAdapter(adapter);

        spinnerType.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener()
        {
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id)
            {
               //When I try to debug, the text value is the given above, a MergeCursor
                text = ((String)spinnerType.getSelectedItem().toString());

                selectedItem = position;
                addSelection();
                //This ones don't have anything in common with the adapter from the spinner, are for a RecyclerView
                initializeData();
                initializeAdapter();
            }
            public void onNothingSelected(AdapterView<?> parent)
            {
            }
        });

不，“文本”不再被使用，所以它的價值沒有改變，我也試過

spinnerType.getSelectedItem().toString();

但得到了相同的結果。

我想要做的就是獲取 Spinner 上文本的字符串值，並將其與R.string.myvalue與text.equals(getString(R.string.myvalue))

Answer 1

你的變量類型是什么？

Answer 2

你可以這樣試試嗎

class MainActivity : AppCompatActivity() {


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val adapter =
            ArrayAdapter(this, android.R.layout.simple_spinner_item, listOf("1", "2", "3"))

        spinner.adapter = adapter

        spinner.onItemSelectedListener = object : AdapterView.OnItemSelectedListener {
            override fun onNothingSelected(parent: AdapterView<*>?) {

            }

            override fun onItemSelected(
                parent: AdapterView<*>?,
                view: View?,
                position: Int,
                id: Long
            ) {
                logDebug(spinner.getItemAtPosition(position))
            }

        }

    }
}

Answer 3

解決方案：由於問題是MergeCursor （我需要它來向我的 Cursor 添加一行），我結束時沒有為微調器使用一個simple cursor adapter ，而是一個ArrayAdapter ，之前添加了帶有“所有”文本的自定義行，並且最近將 Cursor 行一一添加到 ArrayList 中，這樣我就沒有遇到任何問題。

spinnerType = view.findViewById(R.id.spinnerDrinkType);
    //Get the different types of drinks
    Cursor cursorTypes = coctelsOpenHelper.getTypes();

    //Add "All" field to the spinner, for that "all" field is added first to the ArrayList,
    // and later each item of the cursor
    ArrayList<String> spinnerArray = new ArrayList<>();

    spinnerArray.add(getString(R.string.title_all_drinks));
    for(cursorTypes.moveToFirst(); !cursorTypes.isAfterLast(); cursorTypes.moveToNext()) {
        spinnerArray.add(cursorTypes.getString(1));
    }
    ArrayAdapter<String> adapter = new ArrayAdapter<>(
            getContext(), android.R.layout.simple_spinner_item, spinnerArray);
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

    spinnerType.setAdapter(adapter);


    spinnerType.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener()
    {
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id)
        {                
            text = spinnerType.getSelectedItem().toString();

            addSelection();
            initializeData();
            initializeAdapter();
        }
)};