Android：AutoCompleteTextView 和过滤器 - 键入延迟 - 为什么？

Question

好吧，伙计们，这让我发疯了，我在互联网上找不到解决方案！
我做了一个新的 Eclipse 项目并将这段代码粘贴到里面：

https://developers.google.com/places/training/autocomplete-android

它可以工作，但是如果我输入或删除（一个）字符，则在键入它们时通常会出现延迟（短暂冻结），并且建议下拉菜单会消失并再次出现。
至于我的理解，过滤本身是异步完成的，因此来自后台线程，那么为什么短暂冻结？

我的目标是在 Google Play 商店中拥有一个无冻结的 AutoCompleteTextView。
那么你们有什么建议/解决方法来实现这一点吗？

Answer 1

您必须使用以下库文件。您必须在 AutoCompletetextView 上调用 addTextChangeListener(Listener)。在afterTextChanged(Editable s) 里面你必须提到你需要做的功能。

/*
 * Copyright (C) 2006 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.text;

/**
 * When an object of a type is attached to an Editable, its methods will
 * be called when the text is changed.
 */
public interface TextWatcher extends NoCopySpan {
    /**
     * This method is called to notify you that, within <code>s</code>,
     * the <code>count</code> characters beginning at <code>start</code>
     * are about to be replaced by new text with length <code>after</code>.
     * It is an error to attempt to make changes to <code>s</code> from
     * this callback.
     */
    public void beforeTextChanged(CharSequence s, int start,
                                  int count, int after);
    /**
     * This method is called to notify you that, within <code>s</code>,
     * the <code>count</code> characters beginning at <code>start</code>
     * have just replaced old text that had length <code>before</code>.
     * It is an error to attempt to make changes to <code>s</code> from
     * this callback.
     */
    public void onTextChanged(CharSequence s, int start, int before, int count);

    /**
     * This method is called to notify you that, somewhere within
     * <code>s</code>, the text has been changed.
     * It is legitimate to make further changes to <code>s</code> from
     * this callback, but be careful not to get yourself into an infinite
     * loop, because any changes you make will cause this method to be
     * called again recursively.
     * (You are not told where the change took place because other
     * afterTextChanged() methods may already have made other changes
     * and invalidated the offsets.  But if you need to know here,
     * you can use {@link Spannable#setSpan} in {@link #onTextChanged}
     * to mark your place and then look up from here where the span
     * ended up.
     */
    public void afterTextChanged(Editable s);
}

Answer 2

我通过放置这些代码行解决了这个问题（参见 cmets）：

            @Override
            protected FilterResults performFiltering(CharSequence constraint)
            {
                FilterResults filterResults = new FilterResults();

                // ADDED CODE: TO FIX ERROR "The content of the adapter has changed but ListView did not receive a notification":
                ArrayList <String> resultListTemp = new ArrayList <String> ();

                if (constraint != null)
                {
                    // ADDED CODE: TO STOP TYPING DELAY & TO FIX ERROR: "The content of adapter has changed but ListView did not receive a notification"
                    if (conn != null)
                    {
                        conn.disconnect();
                    }

                    // CHANGED CODE: TO FIX ERROR "The content of the adapter has changed but ListView did not receive a notification":
                    resultListTemp.addAll(autocomplete(constraint.toString()));

                    filterResults.values = resultListTemp;
                    filterResults.count = resultListTemp.size();
                }
                return filterResults;
            }


            @Override
            protected void publishResults(CharSequence constraint, FilterResults results)
            {
                // ADDED CODE: TO FIX ERROR "The content of the adapter has changed but ListView did not receive a notification":
                resultList = (ArrayList <String>) results.values;

                if (results != null && results.count > 0)
                {
                    notifyDataSetChanged();
                }
                else
                {
                    notifyDataSetInvalidated();
                }
            }


            private ArrayList<String> autocomplete(String input)
            {
                // CHANGED CODE: TO FIX ERROR "The content of the adapter has changed but ListView did not receive a notification":
                ArrayList<String> resultList = new ArrayList <String> ();
                .....
                .....
            }

其中“conn”是用于获取 Google Places 数据的 HttpURLConnection。