java - 如何在警报对话框中为微调器设置适配器

Question

我在制作 Android 应用程序时发现了一个问题。我有 Activity ，我必须从中发出警报对话框。这很好，但我也需要那个对话框中的微调器，我无法正确设置适配器。应用程序因 NullPointer ex 而崩溃。一段带有微调器的对话框 xml:

    <Spinner
    android:id="@+id/spinner"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="5dp"
    android:drawSelectorOnTop="true" />

这是代码:

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_my_list);
    MyListView = (ListView) findViewById(android.R.id.list);
    registerForContextMenu(MyListView);
    myList = getIntent().getParcelableArrayListExtra(
            MainActivity.NUMBER_LIST);
    for (MyCallLog m : myList) {
        stringList.add(m.getNumber());
    }
    MyListView.setAdapter(new ArrayAdapter<String>(this,
            android.R.layout.simple_list_item_1, stringList) {
    });
}

和对话代码:

public void DialogData(final int DialogTyp) {
    Context mContext = getApplicationContext();
    LayoutInflater inflater = (LayoutInflater) mContext
            .getSystemService(LAYOUT_INFLATER_SERVICE);
    final View layout = inflater.inflate(R.layout.dialog, null);


    AlertDialog.Builder MyBuilder = new AlertDialog.Builder(this);

    MyBuilder.setPositiveButton("OK",
            new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int whichButton) {
                    if (DialogTyp == 1) {

                    }

                    else if (DialogTyp == 2) {
                        stringList.remove(aktual);
                    }

                    MyListView.invalidateViews();
                    return;
                }
            });

    MyBuilder.setNegativeButton("Storno",
            new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int whichButton) {
                    return;
                }
            });

    if (DialogTyp != 2)
        MyBuilder.setView(layout);

    AlertDialog MyAlertDialog = MyBuilder.create();

    if (DialogTyp == 0)
        MyAlertDialog.setTitle("Nový záznam");
    else if (DialogTyp == 1) {
        addItemsOnSpinner();
        MyAlertDialog.setTitle("Editace záznamu");
        ((EditText)layout.findViewById(R.id.cislo)).setText(myCallLog.getNumber());
        ((EditText)layout.findViewById(R.id.delka)).setText(String.valueOf(myCallLog.getDuration()));
        ((EditText)layout.findViewById(R.id.datum)).setText("25.2.2015");
        ((Spinner)layout.findViewById(R.id.spinner)).setSelection(getSelectedOperator(myCallLog.getOperator()));
    } else if (DialogTyp == 2) {
        MyAlertDialog.setTitle("Smazání záznamu" + aktual);
        MyAlertDialog.setMessage("Opravdu chcete smazat vybraný záznam?");
    }

    MyAlertDialog.show();
}

public void editList(int pozition, String number, String date, String spinner){

}

public void addItemsOnSpinner() {


    List<String> list = new ArrayList<String>();
    list.add("O2");
    list.add("T_MOBILE");
    list.add("VODAFONE");
    spinner = (Spinner) findViewById(R.id.spinner);
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(
            this, android.R.layout.simple_spinner_item, list);
        spinner.setAdapter(adapter);
  }

最后一行应该有错误。问题出在哪里或我必须如何正确设置它？

Answer 1

spinner 为空，因为您正尝试从您的 Activity 中findViewById，这不是对话框布局。而是在此处传递您检索到的微调器

((Spinner)layout.findViewById(R.id.spinner))

进入您的 public void addItemsOnSpinner() {...} 方法。