ArrayList
似乎填充得很好,但无论我使用什么方法,我似乎都无法让适配器填充数据。我已经尝试添加到 ArrayList
,也添加到 ArrayAdapter
。无论哪种方式,我都无法在 AutoCompleteTextView
级别或在 ArrayAdapter
本身中获得响应(当然 AutoCompleteTextView
什么也不做) .谁能看出哪里出了问题?
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 显示来自 data.size() 的预期值数量,但来自 autoCompleteAdapter.getCount() 的值为零。
最佳答案
The ArrayList appears to be populating just fine, but no matter what approach I use, I can't seem to get the adapter to populate with data
您违背了 AutoCompleTextView
的工作方式。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,其中包含设法通过过滤请求的值。现在您已经将 AutoCompleteTextView
设置为在每次用户输入字符时创建一个线程,问题是 AutoCompleteTextview
永远不会看到这些值,因为它请求适配器在适配器实际填充正确的值之前进行过滤。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
}
}
获取数据:
public void onTextChanged(CharSequence s, int start, int before, int count) {
if (autoComplete.getThreashold() < s.length()) {
return;
}
queryWebService();
}
您需要在主 UI 线程上更新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。
关于java - AutoCompleteTextView 不响应对其 ArrayAdapter 的更改,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/15375291/