我在不同版本的Android和不同的设备上出现此错误。我已经在我自己的几个设备上测试它并没有得到这个问题,但在某些设备上它一直显示我这个错误
这是ListAdapter代码:
ListAdapter ladap;
private class GetContacts extends AsyncTask<Void, Void, Void> {
@Override
protected Void doInBackground(Void... arg0) {
Spots_tab1_json sh = new Spots_tab1_json();
String jsonStr = sh.makeServiceCall(url + page, Spots_tab1_json.GET);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
contacts = jsonObj.getJSONArray(TAG_CONTACTS);
for (int i = 0; i < contacts.length(); i++) {
JSONObject c = contacts.getJSONObject(i);
String id = new String(c.getString("id").getBytes("ISO-8859-1"), "UTF-8");
String dates = new String(c.getString("dates").getBytes("ISO-8859-1"), "UTF-8");
String price = new String(c.getString("gheymat").getBytes("ISO-8859-1"), "UTF-8");
HashMap<String, String> contact = new HashMap<String, String>();
contact.put("id", id);
contact.put("dates", dates);
contact.put("price", price);
contactList.add(contact);
}
}
} catch (JSONException e) {
goterr = true;
} catch (UnsupportedEncodingException e) {
goterr = true;
}
} else {
goterr = true;
}
return null;
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
if (!isCancelled() && goterr == false) {
if(ladap==null){
ladap=new ListAdapter(MainActivity.this, contactList);
lv.setAdapter(ladap);
}else{
ladap.addAll(contactList);
}
}
}
public class ListAdapter extends BaseAdapter {
Activity activity;
public ArrayList<HashMap<String, String>> list;
public ListAdapter(Activity activity,ArrayList<HashMap<String, String>> list) {
super();
this.activity = (Activity) activity;
this.list = list;
}
public void addAll(ArrayList<HashMap<String, String>> contactList) {
this.list = contactList;
notifyDataSetChanged();
}
public int getCount() {
return contactList.size();
}
public Object getItem(int position) {
return contactList.get(position);
}
public long getItemId(int arg0) {
return 0;
}
private class ViewHolder {
TextView title,price;
ImageView img ;
//RelativeLayout rl;
}
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
LayoutInflater inflater = activity.getLayoutInflater();
if (convertView == null) {
convertView = inflater.inflate(R.layout.item, null);
holder = new ViewHolder();
holder.title = (TextView) convertView.findViewById(R.id.title);
holder.price = (TextView) convertView.findViewById(R.id.price);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
item = contactList.get(position);
holder.price.setText(item.get("price"));
return convertView;
}
}
在上面的代码中,当谈到onpostExcecute()时,它会检查ladab是否为null,如果它为null,它会进入并生成ListAdapter(我已记录并且它只出现一次)之后,它涉及addAll方法并向Adapter添加新项目。
这是日志:
STACK_TRACE = java.lang.IllegalStateException: The content of the adapter has changed but ListView did not receive a notification. Make sure the content of your adapter is not modified from a background thread, but only from the UI thread. [in ListView(2131034188, class android.widget.ListView) with Adapter(class xx.xx.MainActivity$ListAdapter)]
at android.widget.ListView.layoutChildren(ListView.java:1517)
at android.widget.AbsListView.onLayout(AbsListView.java:1925)
at android.view.View.layout(View.java:7462)
at android.widget.RelativeLayout.onLayout(RelativeLayout.java:962)
at android.view.View.layout(View.java:7462)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1268)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1140)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1057)
at android.view.View.layout(View.java:7462)
at android.widget.FrameLayout.onLayout(FrameLayout.java:338)
at android.view.View.layout(View.java:7462)
at android.support.v4.widget.DrawerLayout.onLayout(DrawerLayout.java:743)
at android.view.View.layout(View.java:7462)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1268)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1140)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1057)
at android.view.View.layout(View.java:7462)
at android.widget.FrameLayout.onLayout(FrameLayout.java:338)
at android.view.View.layout(View.java:7462)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1268)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1140)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1057)
at android.view.View.layout(View.java:7462)
at android.widget.FrameLayout.onLayout(FrameLayout.java:338)
at android.view.View.layout(View.java:7462)
at android.widget.FrameLayout.onLayout(FrameLayout.java:338)
at android.view.View.layout(View.java:7462)
at android.view.ViewRoot.performTraversals(ViewRoot.java:1140)
at android.view.ViewRoot.handleMessage(ViewRoot.java:1859)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:130)
at android.app.ActivityThread.main(ActivityThread.java:3694)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:507)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
at dalvik.system.NativeStart.main(Native Method)
这段代码有什么问题?我已尽我所能,但我没有设法解决它。
你可以帮我/谢谢
答案 0 :(得分:1)
我的代码有点混乱:
if (!isCancelled() && goterr == false) {
if(ladap==null){
ladap=new ListAdapter(MainActivity.this, contactList);
lv.setAdapter(ladap);
}else{
ladap.addAll(contactList);
}
}
让我们说,代码第一次运行,其中:
isCancelled()
是假的
goterr
是假的
ladap
将为null,因为尚未创建。
如果这3个发生,ladap.addAll(contactList);
将不被调用,因为if(ladap==null)
是true
。
尝试这样做:
if (!isCancelled() && goterr == false) {
if(ladap==null){
ladap=new ListAdapter(MainActivity.this, contactList);
lv.setAdapter(ladap);
}
ladap.addAll(contactList); //no neet for else
}
<强>更新强>
试试这个:
if (!isCancelled() && goterr == false) {
if(ladap==null){
ladap=new ListAdapter(MainActivity.this, contactList);
lv.setAdapter(ladap);
}
ladap.addAll(contactList); //no neet for else
lv.invalidateViews();
//lv.invalidate(); //try to call this if invalidateViews is not working, do some trial - error here
}
或者,您只需移动ladap=new ListAdapter(MainActivity.this, contactList);
并将其adapter
设置为onCreate
。
答案 1 :(得分:0)
尝试将onPostExecute
方法的代码放入runOnUiThread
:
if (!isCancelled() && goterr == false) {
runOnUiThread(new Runnable() {
@Override
public void run() {
if(ladap==null){
ladap=new ListAdapter(MainActivity.this, contactList);
lv.setAdapter(ladap);
}else{
ladap.addAll(contactList);
}
}
});
}