I'm trying to list all the contacts in mobile. So far everything was working fine, but when I thought of running my code in AsyncTask I'm getting nothing on screen.
Here is code snippet
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_call_list);
lvCallList = (ListView) findViewById(R.id.lv_call_list);
new AsyncTask<Void, Void, Void>()
{
@Override
protected void onPreExecute()
{
pd = ProgressDialog.show(CallListActivity.this,
"Loading..", "Please Wait", true, false);
}// End of onPreExecute method
@Override
protected Void doInBackground(Void... params)
{
getContacts();
return null;
}// End of doInBackground method
@Override
protected void onPostExecute(Void result)
{
pd.dismiss();
lvCallList.setAdapter(new CustomAdapter(CallListActivity.this));
}//End of onPostExecute method
}.execute((Void[]) null);
count = this.displayContactName.size();
thumbnailsselection = new boolean[count];
}
private void getContacts()
{
ContentResolver cr = getContentResolver();
Cursor cur = cr.query(ContactsContract.Contacts.CONTENT_URI, null,null, null, null);
if (cur.getCount() > 0)
{
while (cur.moveToNext())
{
String id = cur.getString(cur.getColumnIndex(ContactsContract.Contacts._ID));
String name = cur.getString(cur.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));
this.displayContactName.add(name);
if (Integer.parseInt(cur.getString(cur.getColumnIndex(ContactsContract.Contacts.HAS_PHONE_NUMBER))) > 0)
{
Cursor pCur = cr.query( ContactsContract.CommonDataKinds.Phone.CONTENT_URI,
null,
ContactsContract.CommonDataKinds.Phone.CONTACT_ID +" = ?",
new String[]{id},
null);
while (pCur.moveToNext())
{
String phoneNumber = pCur.getString(pCur.getColumnIndex( ContactsContract.CommonDataKinds.Phone.NUMBER));
this.displayContactNumber.add(phoneNumber);
}
pCur.close();
}
}
}
}
public class CustomAdapter extends BaseAdapter
{
/*
* Variables Declaration section
*/
private Context mContext;
public CustomAdapter(Context context)
{
mContext = context;
}//End of CustomAdapter constructor
public int getCount()
{
return count;
}//End of getCount method
public Object getItem(int position)
{
return position;
}//End of getItem method
public long getItemId(int position)
{
return position;
}//End of getItemId method
public View getView(int position, View convertView, ViewGroup parent)
{
return convertView;
}//End of getView method
}//End of CustomAdapter instance inner class
class ViewHolder
{
TextView textviewName;
TextView textviewNumber;
CheckBox checkbox;
int id;
}//End of ViewHolder instance inner class
displayContactName value using break point at pd.dismiss(); is
displayContactName ArrayList (id=830007844896)
array Object[12] (id=830007907208)
[0] "Rrs" (id=830007907144)
[1] "Fgsd" (id=830007920424)
[2] null
[3] null
[4] null
[5] null
[6] null
[7] null
[8] null
[9] null
[10] null
[11] null
modCount 2
size 2
I don't know what's wrong in my code, when I don't use AsyncTask then my code works perfectly fine, but when I use AsyncTask problem comes.
Please help me to solve this puzzle.
Thanks in advance.
You cannot update ui in doInbackground. You should update ui on the ui thread. Set the adapter in onPostExecute.
You can also use runOnUiThread.
Example
To display contact names.
public class MainActivity extends Activity {
ListView lvCallList;
ProgressDialog pd;
ArrayList<String> aa = new ArrayList<String>();
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
lvCallList = (ListView) findViewById(R.id.list);
new AsyncTask<Void, Void, Void>()
{
@Override
protected void onPreExecute()
{
pd = ProgressDialog.show(MainActivity.this,
"Loading..", "Please Wait", true, false);
}// End of onPreExecute method
@Override
protected Void doInBackground(Void... params)
{
getContacts();
return null;
}// End of doInBackground method
@Override
protected void onPostExecute(Void result)
{
pd.dismiss();
ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(MainActivity.this, android.R.layout.simple_list_item_1,aa);
lvCallList.setAdapter(arrayAdapter);
}//End of onPostExecute method
}.execute((Void[]) null);
}
private void getContacts()
{
ContentResolver cr = getContentResolver();
Cursor cur = cr.query(ContactsContract.Contacts.CONTENT_URI, null,null, null, null);
if (cur.getCount() > 0)
{
while (cur.moveToNext())
{
String id = cur.getString(cur.getColumnIndex(ContactsContract.Contacts._ID));
String name = cur.getString(cur.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));
aa.add(name);
if (Integer.parseInt(cur.getString(cur.getColumnIndex(ContactsContract.Contacts.HAS_PHONE_NUMBER))) > 0)
{
Cursor pCur = cr.query( ContactsContract.CommonDataKinds.Phone.CONTENT_URI,
null,
ContactsContract.CommonDataKinds.Phone.CONTACT_ID +" = ?",
new String[]{id},
null);
while (pCur.moveToNext())
{
String phoneNumber = pCur.getString(pCur.getColumnIndex( ContactsContract.CommonDataKinds.Phone.NUMBER));
// this.displayContactNumber.add(phoneNumber);
}
pCur.close();
}
}
}
}
}
Snap shot on my mobile
Edit: 2
public class MainActivity extends Activity {
ListView lvCallList;
ProgressDialog pd;
ArrayList<String> aa = new ArrayList<String>();
ArrayList<String> num= new ArrayList<String>();
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
lvCallList = (ListView) findViewById(R.id.list);
new AsyncTask<Void, Void, Void>()
{
@Override
protected void onPreExecute()
{
pd = ProgressDialog.show(MainActivity.this,
"Loading..", "Please Wait", true, false);
}// End of onPreExecute method
@Override
protected Void doInBackground(Void... params)
{
getContacts();
return null;
}// End of doInBackground method
@Override
protected void onPostExecute(Void result)
{
pd.dismiss();
CustomAdapter cus = new CustomAdapter(MainActivity.this);
// ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(MainActivity.this, android.R.layout.simple_list_item_1,aa);
lvCallList.setAdapter(cus);
}//End of onPostExecute method
}.execute((Void[]) null);
}
private void getContacts()
{
ContentResolver cr = getContentResolver();
Cursor cur = cr.query(ContactsContract.Contacts.CONTENT_URI, null,null, null, null);
if (cur.getCount() > 0)
{
while (cur.moveToNext())
{
String id = cur.getString(cur.getColumnIndex(ContactsContract.Contacts._ID));
String name = cur.getString(cur.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));
aa.add(name);
if (Integer.parseInt(cur.getString(cur.getColumnIndex(ContactsContract.Contacts.HAS_PHONE_NUMBER))) > 0)
{
Cursor pCur = cr.query( ContactsContract.CommonDataKinds.Phone.CONTENT_URI,
null,
ContactsContract.CommonDataKinds.Phone.CONTACT_ID +" = ?",
new String[]{id},
null);
while (pCur.moveToNext())
{
String phoneNumber = pCur.getString(pCur.getColumnIndex( ContactsContract.CommonDataKinds.Phone.NUMBER));
num.add(phoneNumber);
}
pCur.close();
}
}
}
}
public class CustomAdapter extends BaseAdapter
{
/*
* Variables Declaration section
*/
private Context mContext;
public CustomAdapter(Context context)
{
mContext = context;
}//End of CustomAdapter constructor
public int getCount()
{
return aa.size();
}//End of getCount method
public Object getItem(int position)
{
return position;
}//End of getItem method
public long getItemId(int position)
{
return position;
}//End of getItemId method
public View getView(int position, View convertView, ViewGroup parent)
{
ViewHolder holder;
final int pos = position;
if (convertView == null)
{
holder = new ViewHolder();
convertView = LayoutInflater.from(mContext).inflate(R.layout.display_contact, null);
holder.textviewName = (TextView) convertView.findViewById(R.id.textView1);
holder.textviewNumber = (TextView) convertView.findViewById(R.id.textView2);
holder.checkbox = (CheckBox) convertView.findViewById(R.id.checkBox1);
convertView.setTag(holder);
}//End of if condition
else
{
holder = (ViewHolder) convertView.getTag();
}//End of else
holder.checkbox.setId(position);
holder.textviewName.setId(position);
holder.textviewNumber.setId(position);
holder.textviewName.setText(aa.get(position));
holder.textviewNumber.setText("No. "+num.get(position));
holder.id = position;
return convertView;
}//End of getView method
}//End of CustomAdapter instance inner class
static class ViewHolder
{
TextView textviewName;
TextView textviewNumber;
CheckBox checkbox;
int id;
}
}
You can't touch views in Non-UI thread. You must set adapter in onPostExecute();
Use this: (Also, I hope that you keep your contacts somewhere, because I don't see contacts variable in your snippet)
new AsyncTask<Void, Void, Void>()
{
@Override
protected void onPreExecute()
{
pd = ProgressDialog.show(CallListActivity.this,
"Loading..", "Please Wait", true, false);
}// End of onPreExecute method
@Override
protected Void doInBackground(Void... params)
{
getContacts();
return null;
}// End of doInBackground method
@Override
protected void onPostExecute(Void result)
{
arrayAdapter = new ArrayAdapter<String>(CallListActivity.this, R.layout.display_contacts,R.id.tv_single_contact_number,displayContactName);
lvCallList.setAdapter(new CustomAdapter(CallListActivity.this));
pd.dismiss();
}//End of onPostExecute method
}.execute((Void[]) null);
You are trying to call setAdapter in doInBackground which is not running on UI thread. You must pass the result of contact loading from doInBackground(..) to onPostExcecute(..) and there you can create a an adapter and set it in the list view.
I found out the problem, I was trying to initialise count after setting adapter, that was the problem, Thanks stackoverflow and @Raghunandan
protected void onPostExecute(Void result)
{
count = displayContactName.size();
thumbnailsselection = new boolean[count];
lvCallList.setAdapter(new CustomAdapter(CallListActivity.this));
pd.dismiss();
}//End of onPostExecute method
来源：https://stackoverflow.com/questions/17878142/how-to-display-contacts-in-android-using-asynctask