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我一直在努力尋找答案，但很難找到有效的解決方案。如何在使用List Adapter onTextChange時清除ListView中的所有項目？
我嘗試將適配器設置爲null，清除實際列表，但似乎都不起作用。
我正在使用帶有ListAdapter的ListView，並試圖在更改文本時更改搜索文本。
list.clear（）;工作但它不會發生在文本更改。
這裏是我的代碼：
private EditText search_input;
private Button search_button;
// progress bar for search results
private ProgressDialog search_loading;
private ListView wordSearchList;
private ListAdapter adapter;
// no result layout
private LinearLayout no_res;
// create list for adapter
ArrayList<HashMap<String, String>> list;
// database helper
private DatabaseHelper db;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.dictionary_search);
search_input = (EditText) findViewById(R.id.search_dictionary);
search_button = (Button) findViewById(R.id.search_button);
search_button.setOnClickListener(this);
// linear layout for no results
no_res = (LinearLayout) findViewById(R.id.search_result_ll);
// create hashmap list
list = new ArrayList<HashMap<String, String>>();
// remove views if they exist
search_input.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence s, int start, int before,
int count) {
// REMOVE LIST VIEW AND ADAPTER
// list.clear();
if (no_res.getChildCount() > 0) {
no_res.removeAllViews();
}
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
}
@Override
public void afterTextChanged(Editable s) {
}
});
}
@Override
public void onClick(View v) {
if (v == search_button) {
// clear list for fresh start
list.clear();
no_res.removeAllViews();
// validate input and that something was entered
if (search_input.getText().toString().length() < 1) {
// missing required info (null was this but lets see)
Toast.makeText(getApplicationContext(),
"Please search for something!", Toast.LENGTH_LONG)
.show();
} else {
String search_data;
search_data = search_input.getText().toString();
// remove any current views on search again
// REMOVE THE LIST VIEW
// execute the query search
List<DatabaseWordsFTS> search_results = db
.getSingleWordSearch(search_data);
// if no search results returned
if (search_results.size() <= 0) {
TextView no_results_tv = new TextView(this);
no_results_tv.setText("No results found.");
no_res.addView(no_results_tv);
}
// setup listview
wordSearchList = (ListView) findViewById(R.id.wordSearchList);
for (DatabaseWordsFTS word_found : search_results) {
// have to create hashmap in loop
HashMap<String, String> map = new HashMap<String, String>();
// convert d id to long
Integer dictionary_id_convert = (int) (long) word_found._dictionaryId;
// extract dictionary from d-id - since it is not a list and
// just a variable
DatabaseDictionary dictionary_found = db
.getDictionary(dictionary_id_convert);
// extract languages to send below
Integer dln_1 = (int) dictionary_found._language1Id;
Integer dln_2 = (int) dictionary_found._language2Id;
Integer dln_3 = (int) dictionary_found._language3Id;
Integer dln_4 = (int) dictionary_found._language4Id;
// get languages for the words based on ids passed in
List<DatabaseLanguages> LanguagesForD = db
.getAllLanguagesWithId(dln_1, dln_2, dln_3, dln_4);
// add name to hashmap and rest of the data as strings
map.put("w_1", word_found.get_word1_fts());
map.put("l_1", LanguagesForD.get(0)._language_name);
map.put("d_id", String.valueOf(dictionary_id_convert));
map.put("w_id", String.valueOf(word_found.get_id()));
if (word_found.get_word2_fts() != null) {
map.put("w_2", word_found.get_word2_fts());
map.put("l_2", LanguagesForD.get(1)._language_name);
}
if (word_found.get_word3_fts() != null) {
map.put("w_3", word_found.get_word3_fts());
map.put("l_3", LanguagesForD.get(2)._language_name);
}
if (word_found.get_word4_fts() != null) {
map.put("w_4", word_found.get_word4_fts());
map.put("l_4", LanguagesForD.get(3)._language_name);
}
list.add(map);
// used to dismiss progress bar for searching
search_loading.dismiss();
}
String[] from = { "w_1", "w_2", "w_3", "w_4" }; // , "word3",
// "word4"
int[] to = { R.id.textName, R.id.textLanguage };
adapter = new SimpleAdapter(this, list,
R.layout.dictionary_row, from, to);
wordSearchList.setAdapter(adapter);
wordSearchList
.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent,
View view, int position, long id) {
// ListView Clicked item index
int itemPosition = position;
// ListView Clicked item value
HashMap itemValue = (HashMap) wordSearchList
.getItemAtPosition(position);
String w_id = (String) itemValue.get("w_id");
String d_id = (String) itemValue.get("d_id");
String l_1 = (String) itemValue.get("l_1");
String l_2 = (String) itemValue.get("l_2");
String l_3 = (String) itemValue.get("l_3");
String l_4 = (String) itemValue.get("l_4");
String w_1 = (String) itemValue.get("w_1");
String w_2 = (String) itemValue.get("w_2");
String w_3 = (String) itemValue.get("w_3");
String w_4 = (String) itemValue.get("w_4");
// Show Alert
Toast.makeText(
getApplicationContext(),
"Position :" + itemPosition
+ " ListItem : " + w_id,
Toast.LENGTH_LONG).show();
// creating bundle
Bundle d_data = new Bundle();
// add to bundle
d_data.putString("w_id", w_id);
d_data.putString("wd_id", d_id);
d_data.putString("w_1", w_1);
d_data.putString("l_1", l_1);
// get tags only if it exists
if (w_2 != null) {
d_data.putString("w_2", w_2);
d_data.putString("l_2", l_2);
}
if (w_3 != null) {
d_data.putString("w_3", w_3);
d_data.putString("l_3", l_3);
}
if (w_4 != null) {
d_data.putString("w_4", w_4);
d_data.putString("l_4", l_4);
}
// start new intent based on the tag -
Intent single_word_view = new Intent(
DictionaryWordSearch.this,
DictionarySingleWordView.class);
// call extras
single_word_view.putExtras(d_data);
// new_dictionary_view.putExtra("d_id",
// WhatAmISupposeToPassInHere);
startActivity(single_word_view);
}
});
}
編輯：（以下爲我工作）
更改ListAdapter到SimpleAdapter
if(adapter != null){list.clear(); adapter.notifyDataSetChanged();}
添加上面的代碼中onTextChange
使用適配器。 clear（）和Adapter.notifyDataSetChanged（） –
不適用於列表適配器 – Lion789