AutoCompleteTextView无法响应其ArrayAdapter的更改

Question

在ArrayList似乎是填充就好了,但是不管我用什么方法,我似乎无法获取适配器来填充数据.我已经尝试过添加到了ArrayList,也是为了ArrayAdapter.无论哪种方式,我都无法在AutoCompleteTextView关卡或ArrayAdapter自身中得到回应(当然AutoCompleteTextView也无所作为).有人能看出什么问题吗？

public class MainActivity extends Activity implements TextWatcher {
// private AutoCompleteView autoComplete; 
public String TAG = new String("MAINACTIVITY");
public ArrayAdapter<String> autoCompleteAdapter;
public AutoCompleteTextView autoComplete;
public InputStream inputStream;
public List<String> data;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    data = new ArrayList<String>();
    autoCompleteAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_dropdown_item_1line, data);
    autoCompleteAdapter.setNotifyOnChange(true);
    autoComplete = (AutoCompleteTextView) findViewById(R.id.acsayt);
    autoComplete.setHint(R.string.search_hint);
    autoComplete.setThreshold(2);
    autoComplete.addTextChangedListener(this);
    autoComplete.setAdapter(autoCompleteAdapter);
}

// uphold TextWatcher interface methods
public void afterTextChanged(Editable s) {
}
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}

public void onTextChanged(CharSequence s, int start, int before, int count) {
    Log.d(TAG, "I detected a text change " + s.toString());
    data.clear();
    queryWebService();
}

private void queryWebService() {
    new Thread(new Runnable() {
        public void run() {
            Log.d(TAG, "spawned thread");

            //  Code in here to set up http connection, query webservice ...

            // parse the JSON response & add items to adapter
            try {
                JSONArray jArray = new JSONArray(resultString);
                int length = jArray.length();
                int countedValues, capturedValues;
                Log.d(TAG, "response had " + length + " items");
                int i = 0;
                while (i < length) {
                    JSONObject internalObject = jArray.getJSONObject(i);
                    String vehicleName = internalObject.getString("name").toString();
                    Log.d(TAG, "vehicle name is " + vehicleName);
                    try {
                        data.add(vehicleName);  
                        autoCompleteAdapter.add(vehicleName);   // not working
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                    countedValues = data.size();    // correctly reports 20 values
                    capturedValues = autoCompleteAdapter.getCount();    //  is zero
                    Log.d(TAG, "array list holds " + countedValues + " values");
                    Log.d(TAG, "array adapter holds " + capturedValues + " values");
                    i++;
                }
            } catch (Exception e) {
                Log.d(TAG, "JSON manipulation err: " + e.toString());
            }
        }
    }).start();
}

}

LogCat显示data.size()的预期值,但autoCompleteAdapter.getCount()为零.

Answer 1

ArrayList似乎填充得很好,但无论我使用什么方法,我似乎无法让适配器填充数据

你反对的是如何AutoCompleTextView工作.当用户开始在输入框中输入字符时,AutoCompleteTextView将过滤适配器,当发生这种情况时,它将显示下拉列表,其中包含设法传递过滤器请求的值.现在,您已经设置了AutoCompleteTextView每次用户输入字符时创建一个线程,问题是,AutoCompleteTextview在适配器实际填充正确的值之前,它将永远不会看到这些值,因为它请求适配器进行过滤.尝试这样的事情:

public static class BlockingAutoCompleteTextView extends
        AutoCompleteTextView {

    public BlockingAutoCompleteTextView(Context context) {
        super(context);
    }

    @Override
    protected void performFiltering(CharSequence text, int keyCode) {           
        // nothing, block the default auto complete behavior
    }

}

并获取数据:

public void onTextChanged(CharSequence s, int start, int before, int count) {
    if (autoComplete.getThreashold() < s.length()) {
        return;
    } 
    queryWebService();
}

您需要更新主UI线程上的数据,并使用适配器的方法:

// do the http requests you have in the queryWebService method and when it's time to update the data:
runOnUiThread(new Runnable() {
        @Override
    public void run() {
        autoCompleteAdapter.clear();
        // add the data
                for (int i = 0; i < length; i++) {
                     // do json stuff and add the data
                     autoCompleteAdapter.add(theNewItem);                    
                } 
                // trigger a filter on the AutoCompleteTextView to show the popup with the results 
                autoCompleteAdapter.getFilter().filter(s, autoComplete);
    }
});

看看上面的代码是否有效.