我一直在解決這個問題,我已經準備好將我的頭髮拉出來。我在這裏和網絡上發現了一些答案,說這是由於嘗試在線程中(而不是在UI線程中)使用View來完成某些操作而導致的。但我已經嘗試過所有我見過的想法(處理程序/新線程),但仍然無法實現。我在C編程多年是一種愛好,現在我是Java/Android的新手。我正在使用Eclipse和Android 2.1平臺進行編程。我希望我的應用程序能夠儘可能多地使用Android手機,並且我認爲我使用的所有功能都與API 1兼容。我還看到有一些名爲AsyncTask的內容,但會導致問題有舊手機的人?Android:出現錯誤「只有創建視圖層次結構的原始線程才能觸及其視圖」
所以這裏是我的應用程序。當我點擊一個按鈕時,該應用程序將聯機到一個網站並下載一個xml/rss提要。然後它解析它,並使用我創建的自定義適配器將數據放入列表視圖中。下載和解析可能需要1秒到15秒的時間,所以我想添加一個進度對話框。添加後,這就是我開始在這篇文章的標題中獲得錯誤信息的地方。該應用程序成功下載(我網上的示例xml文件有8條記錄,因此它非常小),但是在顯示列表視圖之前我看到了錯誤。所以我想我需要知道視圖的哪個部分導致錯誤,然後如何解決它。
下面是代碼(我已刪除所有來自最後幾個小時我的測試代碼,以便它是乾淨的,會越來越混亂,所有的你......和我):
@SuppressWarnings("serial")
public class ClubMessageList extends ListActivity implements Serializable
{
private static final String TAG = "DGMS News";
private ArrayList<CMessage> m_messages = null;
private MessageAdapter m_adapter;
private ProgressDialog m_ProgressDialog = null;
private Runnable downloadMessages;
// Need handler for callbacks to the UI thread
final Handler mHandler = new Handler();
@SuppressWarnings("unchecked")
@Override
public void onCreate(Bundle icicle)
{
Log.i(TAG, "Starting the ClubMessageList activity");
super.onCreate(icicle);
setContentView(R.layout.list);
setTitle("DGMS News - Clubs");
try
{
// check to see if we already have downloaded messages available in the bundle
m_messages = (ArrayList<CMessage>) ((icicle == null) ? null : icicle.getSerializable("savedMessages"));
// if there are no messages in the bundle, download them from the web and then display them
if (m_messages == null)
{
m_messages = new ArrayList<CMessage>();
this.m_adapter = new MessageAdapter(this, R.layout.row_club, (ArrayList<CMessage>) m_messages);
setListAdapter(this.m_adapter);
downloadMessages = new Runnable(){
public void run() {
getMessages();
}
};
Thread thread = new Thread(null, downloadMessages, "DownloadMessages");
thread.start();
m_ProgressDialog = ProgressDialog.show(ClubMessageList.this,
"Please wait...", "Retrieving 2010 Show data ...", true);
}
else // messages were already downloaded, so display them in the listview (don't download them again)
{
Log.i("DGMS News", "Starting activity again. Data exists so don't retrieve it again.");
m_adapter = new MessageAdapter(this, R.layout.row_club, (ArrayList<CMessage>) m_messages);
this.setListAdapter(m_adapter);
}
}
catch (Throwable t)
{
Log.e("DGMS News",t.getMessage(),t);
}
}
private Runnable returnRes = new Runnable()
{
public void run()
{
if(m_messages != null && m_messages.size() > 0)
{
m_adapter.notifyDataSetChanged();
for(int i=0;i<m_messages.size();i++)
m_adapter.add(m_messages.get(i));
}
m_ProgressDialog.dismiss();
m_adapter.notifyDataSetChanged();
}
};
private void getMessages()
{
try
{
m_messages = new ArrayList<CMessage>();
ClubFeedParser parser = ClubFeedParserFactory.getParser();
m_messages = parser.parse();
for(int i = 0; i < m_messages.size(); i++)
m_adapter.add(m_messages.get(i));
}
catch (Exception e)
{
Log.e("DGMS News", e.getMessage());
}
runOnUiThread(returnRes);
}
protected void onSaveInstanceState(Bundle outState)
{
super.onSaveInstanceState(outState);
outState.putSerializable("savedMessages", (Serializable) m_messages);
}
@Override
protected void onListItemClick(ListView l, View v, int position, long id)
{
super.onListItemClick(l, v, position, id);
Intent intent = new Intent(ClubMessageList.this, ClubDetails.class);
// Add all info about the selected club to the intent
intent.putExtra("title", m_messages.get(position).getTitle());
intent.putExtra("location", m_messages.get(position).getLocation());
intent.putExtra("website", m_messages.get(position).getLink());
intent.putExtra("email", m_messages.get(position).getEmail());
intent.putExtra("city", m_messages.get(position).getCity());
intent.putExtra("contact", m_messages.get(position).getContact());
intent.putExtra("phone", m_messages.get(position).getPhone());
intent.putExtra("description", m_messages.get(position).getDescription());
startActivity(intent);
}
private class MessageAdapter extends ArrayAdapter<CMessage> implements Serializable
{
private ArrayList<CMessage> items;
public MessageAdapter(Context context, int textViewResourceId, ArrayList<CMessage> items)
{
super(context, textViewResourceId, items);
this.items = items;
}
public View getView(int position, View convertView, ViewGroup parent)
{
View v = convertView;
if (v == null)
{
LayoutInflater vi = (LayoutInflater)getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = vi.inflate(R.layout.row_club, null);
CMessage m = items.get(position);
if (m != null)
{
TextView ltt = (TextView) v.findViewById(R.id.ltoptext);
TextView rtt = (TextView) v.findViewById(R.id.rtoptext);
TextView lbt = (TextView) v.findViewById(R.id.lbottext);
if (ltt != null)
ltt.setText(m.getTitle());
if (rtt != null)
rtt.setText(m.getLocation());
if (lbt != null)
lbt.setText(m.getCity() + ", CO");
//if (rbt != null)
; // not used in this list row
}
}
return v;
}
}
}
由於我說,所有這些代碼工作良好,直到我添加了前幾天在另一個網站上找到的進度對話框。
我很感激任何和所有的幫助,雖然我已經去過Android Developers網站查看線程,處理程序等,它讓我越來越困惑。實際的代碼更改會很棒。 :-)今天看到這麼多網站後,我的頭很痛。
謝謝!
鮑勃
@ user593424:謝謝!這解決了它。而且我實際上在我的代碼中加載了兩次列表,所以我也修復了這個問題。非常感謝! – Bobert 2011-04-15 04:34:42