ListViewにアニメーションを追加しようとしています。これにより、HTTP GETリクエストから結果が届くと、テキストが別々の行にフェードインします。フェードイン効果を実行する方法を知っていて、カスタムListViewアダプターを既に持っていますが、問題は、結果が入るたびにListViewがすべての行を更新するため、リスト全体に対して毎回フェードイン効果がトリガーされることです。
ListViewがデータの変更ごとにすべての行をアニメーション化しないように、単一の行を制御するにはどうすればよいですか？
これは、ListViewを埋めるために使用するコードです。
private class CustomAdapter extends ArrayAdapter<Row> {
public CustomAdapter() {
super(Results.this, R.layout.row, dataList);
}
public View getView(int position, View convertView, ViewGroup parent) {
View row = convertView;
RowHolder holder = null;
if (row == null) {
LayoutInflater inflater = getLayoutInflater();
row = inflater.inflate(R.layout.row, parent, false);
holder = new RowHolder(row);
row.setTag(holder);
} else {
holder = (RowHolder) row.getTag();
}
try {
holder.populateRow(dataList.get(position));
} catch (NullPointerException e) {
e.printStackTrace();
}
return row;
}
}
private class RowHolder {
private TextView label = null;
private TextView count = null;
private TextView result = null;
public RowHolder(View row) {
label = (TextView) row.findViewById(R.id.list_label);
count = (TextView) row.findViewById(R.id.list_count);
result = (TextView) row.findViewById(R.id.list_result);
}
public void populateRow(Row r) {
label.setText(r.getLabel());
count.setText(r.getCount());
result.setText(r.getResult());
label.startAnimation(fadeIn);
count.startAnimation(fadeIn);
result.startAnimation(fadeIn);
}
}
どんな助けでもありがたいです、前もってありがとう！
編集1：
私のAsyncTask：
private class CheckSource extends AsyncTask<String, Void, String> {
protected void onPreExecute() {
results.setUnixTime(getUnixTime());
results.setLabel(getString(R.string.label));
results.setCount(null);
results.setResult(null);
results.setResultLabel("");
results.setShowProgress(true);
results.setIconType(null);
results.setShowIcon(false);
results.setHasResults(false);
adapter.notifyDataSetChanged();
}
@Override
protected String doInBackground(String... params) {
String query = params[0];
String httpResults = null;
try {
httpResults = getResults(query, "source");
jsonObject = new JSONObject(httpResults);
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
} catch (URISyntaxException e) {
e.printStackTrace();
}
return httpResults;
}
protected void onPostExecute(String results) {
try {
parseJSON(results);
} catch (JSONException e) {
e.printStackTrace();
results.setResultLabel("<br />"
+ getString(R.string.source_not_available) + "<br />");
}
results.setShowProgress(false);
adapter.notifyDataSetChanged();
}
// Parse the retrieved json results
private void parseJSON(String jsonResults) throws JSONException {
if (jsonResults == null) {
results.setResult(null);
results.setHasResults(false);
results.setResultLabel("<br />"
+ getString(R.string.source_not_available) + "<br />");
return;
}
jsonObject = new JSONObject(jsonResults);
String result = null;
String resultLabel = null;
switch (jsonObject.getInt("count")) {
case -1:
results.setCount(null);
results.setHasResults(false);
resultLabel = getString(R.string.no_results);
break;
case 0:
results.setCount(null);
results.setHasResults(false);
resultLabel = getString(R.string.no_results);
break;
case 1:
results.setHasResults(true);
results.setCount(jsonObject.get("count").toString() + " "
+ getString(R.string.one_result));
result = jsonObject.get("url").toString();
resultLabel = getString(R.string.hyperlink_text);
break;
default:
results.setHasResults(true);
results.setCount(jsonObject.get("count").toString() + " "
+ getString(R.string.multiple_results));
result = jsonObject.get("url").toString();
resultLabel = getString(R.string.hyperlink_text);
break;
}
results.setResult(result);
results.setResultLabel("<br />" + resultLabel + "<br />");
}
}
HTTPリクエストを実行するメソッド：
private String getResults(String query, String source)
throws IllegalStateException, IOException, URISyntaxException {
/* Method variables */
StringBuilder builder = new StringBuilder();
String URL = "url";
URI uri;
String phrase = "phrase";
List<NameValuePair> params = new ArrayList<NameValuePair>();
/* HTTP variables */
HttpGet httpGet;
DefaultHttpClient httpClient;
HttpResponse httpResponse;
HttpEntity httpEntity;
HttpParams httpParams;
int socketTimeout = 10000;
int connectionTimeout = 10000;
// Set the socket and connection timeout values
httpParams = new BasicHttpParams();
HttpConnectionParams
.setConnectionTimeout(httpParams, connectionTimeout);
HttpConnectionParams.setSoTimeout(httpParams, socketTimeout);
httpClient = new DefaultHttpClient(httpParams);
// Add parameters to the GET request
params.add(new BasicNameValuePair("query", query));
params.add(new BasicNameValuePair("type", source));
String paramString = URLEncodedUtils.format(params, "utf-8");
uri = new URI(URL + paramString);
httpGet = new HttpGet(uri);
// Execute the GET request
httpResponse = httpClient.execute(httpGet);
/* Read http response if http status = 200 */
if (httpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
httpEntity = httpResponse.getEntity();
InputStream content = httpEntity.getContent();
BufferedReader reader = new BufferedReader(new InputStreamReader(
content));
String line;
while ((line = reader.readLine()) != null) {
builder.append(line);
}
}
return builder.toString();
}