为什么我的 BaseAdapter 类不增加 getView 中的位置？

Question

编辑：我的问题似乎是 BaseAdapter 只是不会发布超过 1 个 Spinner。如果我将数组的大小更改为 0，它不会放任何东西，但任何超过 1 的东西都会截断它。它永远不会从getView() 传递位置 0，并且它永远不会超过 1。我已经在它上面做了几个小时。这是有原因的吗？

我在使用BaseAdapter 在ListView 中动态添加Spinners 时遇到问题。我之前尝试过它作为测试，以确保它可以在测试类中正确完成，并且它可以正确地迭代位置。但现在我又做了一次，但它失败了。我所说的失败不是getView() 创建新的Spinner，而是永远不会离开位置0。它仍然运行。只是永远不要添加更多Spinners。 这是我的代码：

主适配器代码

---

public class RemindersAdapter extends BaseAdapter{
Spinner[] shownReminders = new Spinner[1];
TextView[] removeReminders = new TextView[1];
String[] reminders = new String[1]; //this hlds the values of the coresponding spinner

RemindersAdapter mAdapter;


@Override
public int getCount() {
    return shownReminders.length;
}

@Override
public Object getItem(int position) {
    return shownReminders[position];
}

@Override
public long getItemId(int position) {
    return position;
}

@Override
public View getView(int position, View view, ViewGroup parent) {
    Log.d("TAG", "A NEW SPINNER AND TEXTVIEW IS CREATED HERE WITH POSITION"+position);
    if(view == null) {
        LayoutInflater inflater = LayoutInflater.from(parent.getContext());
        view = inflater.inflate(R.layout.reminder_spinner, parent, false);
    }

    Spinner reminderSpinner = (Spinner)view.findViewById(R.id.reminder_spinner);
    reminderSpinner.setTag(String.valueOf(position));
    ArrayAdapter<CharSequence> reminderAdapter = ArrayAdapter.createFromResource(
            parent.getContext(), R.array.reminders_array, android.R.layout.simple_spinner_item);
    reminderAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    reminderSpinner.setAdapter(reminderAdapter);
    reminderSpinner.setOnItemSelectedListener(new MyOnReminderSelectedListener());
    shownReminders[position] = reminderSpinner;

    TextView remove = (TextView)view.findViewById(R.id.remove_reminder);
    remove.setTag(String.valueOf(position));
    removeReminders[position] = remove;
    remove.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Log.d("The Array positioning of this remove view is: ", ""+v.getTag());

        }
    });


    return view;
}


public void addReminder() {
    Log.d("addReminder METHOD", "The Add Reminder method is running");

    Spinner[] temp = new Spinner[shownReminders.length+1];
    TextView[] temp2 = new TextView[removeReminders.length+1];
    String [] temp3 = new String[reminders.length+1];
    for(int i = 0; i < shownReminders.length; i++) {
        temp[i] = shownReminders[i];
        temp2[i] = removeReminders[i];
        temp3[i] = reminders[i];
    }
    shownReminders = temp;
    removeReminders = temp2;
    reminders = temp3;
    mAdapter.notifyDataSetChanged();//this just makes the adapter refresh itself

}

public void giveYourself(RemindersAdapter adapter) {
    mAdapter = adapter;
}


public class MyOnReminderSelectedListener implements OnItemSelectedListener{

    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int pos,
            long id) {
        int position = Integer.parseInt(parent.getTag().toString()); //gets the position of the Spinner and puts it in the same index in the reminders array
        reminders[position] = parent.getItemAtPosition(pos).toString();
        for(int i =0; i < reminders.length; i++) Toast.makeText(parent.getContext(), i+": "+reminders[i], Toast.LENGTH_SHORT).show();
    }
    @Override
    public void onNothingSelected(AdapterView<?> arg0) {
        // Do nothing for now   
    }   
}//end of MyOnReminderSelectedListener innerclass   


}//end of Class

---

Activity 中运行的内容

---

reminderList = (ListView)findViewById(R.id.reminders_list);
    reminderAdapter = new RemindersAdapter();
    reminderAdapter.giveYourself(reminderAdapter);
    reminderList.setAdapter(reminderAdapter);

    TextView addReminder = (TextView)findViewById(R.id.add_reminder);
    addReminder.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Log.d("TAG", "The onClick is running !");
            reminderAdapter.addReminder();
        }
    });

---

我不知所措，因为我的代码看起来与我的测试代码一模一样，只是做了一些修改才能与我的应用程序一起使用。但是Adapter 使用的信息几乎相同。我也将发布测试代码，以便你们可以看到有效的代码。

测试代码

---

public class RemindersAdapter extends BaseAdapter{
Spinner[] shownReminders = new Spinner[1];
ArrayList<TextView> removeSpinner = new ArrayList<TextView>();
Context mContext;

public RemindersAdapter(Context context) {
    mContext = context;
}

@Override
public int getCount() {
    // TODO Auto-generated method stub
    return shownReminders.length;
}

@Override
public Object getItem(int position) {
    // TODO Auto-generated method stub
    return shownReminders[position];
}

@Override
public long getItemId(int position) {
    // TODO Auto-generated method stub
    return position;
}

@Override
public View getView(int position, View view, ViewGroup parent) {
    Log.d("TAG", "Number of times this is running"+position);
    Log.d("TAG", "Address of the Spinner Object"+shownReminders[position]);
    if(view == null) {
        LayoutInflater inflater = LayoutInflater.from(parent.getContext());
        view = inflater.inflate(R.layout.reminder_spinner, parent, false);
    }

    Spinner reminderSpinner = (Spinner)view.findViewById(R.id.reminders_spinner);
    reminderSpinner.setTag("1"); 
    ArrayAdapter<CharSequence> reminderAdapter = ArrayAdapter.createFromResource(
            parent.getContext(), R.array.reminders_array, android.R.layout.simple_spinner_item);
    reminderAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    reminderSpinner.setAdapter(reminderAdapter);
    reminderSpinner.setOnItemSelectedListener(new MyOnReminderSelectedListener());
    shownReminders[position] = reminderSpinner;

    TextView remove = (TextView)view.findViewById(R.id.remove_reminder);
    remove.setTag(position);
    removeSpinner.add(remove);
    remove.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            int pos = Integer.parseInt(v.getTag().toString());
            removeSpinner.remove(pos);
            Spinner[] temp = new Spinner[shownReminders.length-1];
            for(int i =0; i < shownReminders.length; i++) {
                if(i == pos || i > pos) {
                    temp[i-1] = shownReminders[i];
                } else {
                    temp[i] = shownReminders[i];
                }
            }
            //Here i should refresh somewhow

        }
    });

    return view;
}

public void addReminder() {
    Spinner[] temp = new Spinner[shownReminders.length+1];
    for(int i = 0; i < shownReminders.length; i++) {
        temp[i] = shownReminders[i];
    }
    shownReminders = temp;
}


/*
 * Listener for when the reminder spinner gets a value the user entered
 * */
public class MyOnReminderSelectedListener implements OnItemSelectedListener{

    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int pos,
            long id) {
        //does nothing for now

    }
    @Override
    public void onNothingSelected(AdapterView<?> arg0) {
        // Do nothing for now   
    }   
}//end of MyOnReminderSelectedListener innerclass

---

我还有一个问题，为什么适配器会如此频繁地自行运行。例如，使用 Log，我注意到它无缘无故地调用了两次 getView()。它有这种行为很奇怪。我想我不太了解BaseAdapter。

Answer 1

如果您将 ListView 放在 ScrollView 中，则会发生此错误。 ListView 本身会进行垂直滚动，因此不能将其放入 ScrollView。

Answer 2

当 listView 需要显示新项目时，适配器将调用 getView。因此，如果您的 listView 没有滚动，则不会创建新项目，也不会调用 getView。
但是您不应该存储所有微调器对象，或在 getView 中创建新对象。那是因为它会很慢并且可能会浪费内存。