我已经编写了一些代码来将数据从网页设置为listview。我已成功阅读网页，并在String数组中存储了必要的数据。现在我想使用ListView将其分配给ArrayAdapter，但数据未在listview中设置。请帮我解决错误：
输出logcat以验证数据是否存储在String array
11-07 23:03:47.640: I/NEW VAUES(3192): Happiness is Like a Butterfly, You run after it, It keeps flying away. But if you stand still, It comes and Sits On You Wish you lots of Butterflies
11-07 23:03:47.640: I/NEW VAUES(3192): Happiness is Like a Butterfly, You run after it, It keeps flying away. But if you stand still, It comes and Sits On You Wish you lots of Butterfly
11-07 23:03:47.640: I/NEW VAUES(3192): Happiness is Like a Butterfly, You run after it, It keeps flying away. But if you stand still, It comes and Sits On You Wish you lots of Butterfies
11-07 23:03:47.640: I/NEW VAUES(3192): Happiness is Like a Butterfly, You run after it, It keeps flying away. But if you stand still, It comes and Sits On You Wish you lots of Butterfly
11-07 23:03:47.640: I/NEW VAUES(3192): Happiness is Like a Butterfly, You run after it, It keeps flying away. But if you stand still, It comes and Sits On You Wish you lots of Butterflies
11-07 23:03:47.640: I/VALUES(3192): Happiness is Like a Butterfly, You run after it, It keeps flying away. But if you stand still, It comes and Sits On You Wish you lots of Butterflies<br/>Happiness is Like a Butterfly, You run after it, It keeps flying away. But if you stand still, It comes and Sits On You Wish you lots of Butterfly<br/>Happiness is Like a Butterfly, You run after it, It keeps flying away. But if you stand still, It comes and Sits On You Wish you lots of Butterfies<br/>Happiness is Like a Butterfly, You run after it, It keeps flying away. But if you stand still, It comes and Sits On You Wish you lots of Butterfly<br/>Happiness is Like a Butterfly, You run after it, It keeps flying away. But if you stand still, It comes and Sits On You Wish you lots of Butterflies
CODE
private Spinner spinner1;
private ProgressDialog pd;
private StringBuilder response;
private ListView listView;
private String[] values = new String[0];
private ArrayAdapter<String> adapter;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = (ListView) findViewById(R.id.mylist);
spinner1 = (Spinner) findViewById(R.id.spinnerCategory);
spinner1.setOnItemSelectedListener(new OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> av, View view, int id,
long ids) {
new sendMessageAsync().execute();
}
public void onNothingSelected(AdapterView<?> av) {
}
});
adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, android.R.id.text1, values);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
private class sendMessageAsync extends AsyncTask<Void, Void, String> {
@Override
protected void onPreExecute() {
pd = ProgressDialog.show(main.this, null, "Loading...",
true, true);
}
@Override
protected void onCancelled() {
Toast.makeText(getApplicationContext(),
"Message Sending Cancelled", Toast.LENGTH_LONG).show();
}
@Override
protected String doInBackground(Void... arg0) {
try {
doInBg();
} catch (Exception ex) {
ex.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(String result) {
pd.dismiss();
adapter.notifyDataSetChanged();
listView.setAdapter(adapter);
}
}
public void doInBg() {
try {
final String msgURL = "http://example.com/messages.php?category=" + String.valueOf(spinner1.getSelectedItem().toString().replace(" ", "%20"));
URLConnection connection = new URL(msgURL).openConnection();
connection.setRequestProperty("Accept-Charset", "UTF-8");
InputStream responseStream = connection.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(responseStream));
response = new StringBuilder();
String line;
while ((line = br.readLine()) != null) {
response.append(line);
}
values = String.valueOf(response).split("<br/>");
for (int i = 0; i < values.length;i++) {
Log.i("NEW VAUES", values[i]);
}
Log.i("VALUES", String.valueOf(response));
} catch (Exception ex) {
ex.printStackTrace();
}
}
答案 0 :(得分：2)
您并未更改适配器存储的阵列。当你这样做时：
values = String.valueOf(response).split("<br/>");
您正在类成员中存储新数组，但您的适配器仍保留旧数组。您可以创建和设置新适配器，但此解决方案不利于提高性能。相反，您必须从这个新数组中将每个项添加到适配器。试试这个：
private class sendMessageAsync extends AsyncTask<Void, Void, String> {
@Override
protected void onPreExecute() {
pd = ProgressDialog.show(main.this, null, "Loading...",
true, true);
}
@Override
protected void onCancelled() {
Toast.makeText(getApplicationContext(),
"Message Sending Cancelled", Toast.LENGTH_LONG).show();
}
@Override
protected String doInBackground(Void... arg0) {
try {
return doInBg();
} catch (Exception ex) {
ex.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(String result) {
pd.dismiss();
if (result == null) {
// request failed!
// return;
}
values = String.valueOf(result).split("<br/>");
adapter.clear();
for (String str : values)
adapter.add(str);
}
}
public String doInBg() {
try {
final String msgURL = "http://example.com/messages.php?category=" + String.valueOf(spinner1.getSelectedItem().toString().replace(" ", "%20"));
URLConnection connection = new URL(msgURL).openConnection();
connection.setRequestProperty("Accept-Charset", "UTF-8");
InputStream responseStream = connection.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(responseStream));
response = new StringBuilder();
String line;
while ((line = br.readLine()) != null) {
response.append(line);
}
} catch (Exception ex) {
ex.printStackTrace();
}
return response;
}
答案 1 :(得分：0)
试试这个：
@Override
protected void onPostExecute(String result) {
pd.dismiss();
adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, android.R.id.text1, values);
listView.setAdapter(adapter);
}
适配器值未在代码中更新。