android - android 中的地理编码器自动完成

Question

我一直在谷歌上搜索我的屁股，试图找到一个和我有同样问题的人，但不幸的是。所以这是我的问题:

我正在尝试在用户使用 Android 中的地理编码器键入地点名称时实现地址自动完成建议。我希望它的行为与使用组合框的 javascript 版本非常相似。

我正在使用一个带有 AutoCompleteTextView 的布局和一个数组适配器来在用户键入时动态更新建议列表。我在使用处理程序调用 geocoder.getFromLocationName 之前添加了 500 毫秒的延迟，从收到 onTextChanged() 事件开始。如果用户在 500 毫秒内键入更多字母，则最后一个事件将被取消。我遇到的问题是这些建议几乎从不在 UI 中显示为下拉列表中的可选项。我得到了地址建议，但是当我将它们添加到连接到 autocomplatetextview 的适配器时，它们根本不会显示。

我正在使用 API 级别 7 的模拟器上运行它，其中包括谷歌 API。

现在一些源代码可以帮助您:布局:

<LinearLayout android:id="@+id/searchInputLayout"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:padding="6dip"
    android:orientation="vertical">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/searchMessage" />
    <EditText android:id="@+id/freetextInput" 
        android:hint="@string/searchFreetextLabel"
        android:layout_width="fill_parent" 
        android:layout_height="wrap_content" 
        android:background="@android:drawable/editbox_background" />
    <CheckBox android:id="@+id/includeVincinityCheckbox"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/includeVincinityLabel"
        android:checked="true"
        android:onClick="includeVincinityClick" />
    <AutoCompleteTextView android:id="@+id/locationInput" 
        android:hint="@string/locationInputHint"
        android:layout_width="fill_parent" 
        android:layout_height="wrap_content" />
    <Button android:id="@+id/searchButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/searchBtnLabel" 
        android:onClick="searchBtnClicked" />
    </LinearLayout>

我的 Activity 的源代码(我省略了不相关的代码):

public class SearchLocationTabActivity extends Activity implements TextWatcher, OnItemSelectedListener {

private static final int MESSAGE_TEXT_CHANGED = 0;
private static final int AUTOCOMPLETE_DELAY = 500;
private static final int THRESHOLD = 3;
private String latitude, longitude;
private List<Address> autoCompleteSuggestionAddresses;
private ArrayAdapter<String> autoCompleteAdapter;
private Handler messageHandler;

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

    messageHandler = new MyMessageHandler(this, this);
    autoCompleteAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_dropdown_item_1line, new ArrayList<String>());
    autoCompleteAdapter.setNotifyOnChange(false);
    AutoCompleteTextView locationinput = (AutoCompleteTextView) findViewById(R.id.locationInput);
    locationinput.addTextChangedListener(this);
    locationinput.setOnItemSelectedListener(this);
    locationinput.setThreshold(THRESHOLD);
    locationinput.setAdapter(autoCompleteAdapter);
}

@Override
public void beforeTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) {
    messageHandler.removeMessages(MESSAGE_TEXT_CHANGED);
}

@Override
public void onTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) {
String value = arg0.toString();
if (!"".equals(value) && value.length() >= THRESHOLD) {
    Message msg = Message.obtain(messageHandler, MESSAGE_TEXT_CHANGED, arg0.toString());
    messageHandler.sendMessageDelayed(msg, AUTOCOMPLETE_DELAY);
} else {
    autoCompleteAdapter.clear();
}
}

@Override
public void afterTextChanged(Editable arg0) {
}

@Override
public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
    if (arg2 < autoCompleteSuggestionAddresses.size()) {
        Address selected = autoCompleteSuggestionAddresses.get(arg2);
        latitude = Double.toString(selected.getLatitude());
        longitude = Double.toString(selected.getLongitude());
    }
}

private void notifyResult(List<Address> suggestions) {
    latitude = longitude = null;
    autoCompleteAdapter.clear();
    for (Address a : autoCompleteSuggestionAddresses) {
        autoCompleteAdapter.add(a.toString());//TODO: figure out a nice way to display this address in list
    }
    autoCompleteAdapter.notifyDataSetChanged();
}

@Override
public void onNothingSelected(AdapterView<?> arg0) {
    latitude = longitude = null;
}

private class MyMessageHandler extends Handler {

    private Context context;
    private AsyncTaskSubscriber subscriber;

    public MyMessageHandler(Context context, AsyncTaskSubscriber subscriber) {
        this.context = context;
        this.subscriber = subscriber;
    }

    @Override
    public void handleMessage(Message msg) {
        if (msg.what == MESSAGE_TEXT_CHANGED) {
            String enteredText = (String) msg.obj;

            try {
                autoCompleteSuggestionAddresses = new Geocoder(context).getFromLocationName(enteredText, 10);

                notifyResult(response);
            } catch (IOException ex) {
                Log.e(GeoCoderAsyncTask.class.getName(), "Failed to get autocomplete suggestions", ex);
            }
        }
    }
}
}

非常感谢任何帮助!

Answer 1

对于那些没有设法删除过滤的人，这是我所做的(除了其他小的修改，但我认为它们不会对过滤部分产生影响)。另请注意，对于单击要检测的项目之一，you need to add an OnItemClickListener .

autoCompleteAdapter = new ArrayAdapterNoFilter(this, android.R.layout.simple_dropdown_item_1line);

其中 ArrayAdapterNoFilter 的灵感来自 this other answer :

public class ArrayAdapterNoFilter extends ArrayAdapter<String> {

    public ArrayAdapterNoFilter(Context context, int textViewResourceId) {
        super(context, textViewResourceId);
    }

    private static final NoFilter NO_FILTER = new NoFilter();

    /**
     * Override ArrayAdapter.getFilter() to return our own filtering.
     */
    @Override
    public Filter getFilter() {
        return NO_FILTER;
    }

    /**
     * Class which does not perform any filtering. Filtering is already done by
     * the web service when asking for the list, so there is no need to do any
     * more as well. This way, ArrayAdapter.mOriginalValues is not used when
     * calling e.g. ArrayAdapter.add(), but instead ArrayAdapter.mObjects is
     * updated directly and methods like getCount() return the expected result.
     */
    private static class NoFilter extends Filter {
        protected FilterResults performFiltering(CharSequence prefix) {
            return new FilterResults();
        }

        protected void publishResults(CharSequence constraint, FilterResults results) {
            // Do nothing
        }
    }
}