我编写了一个活动，它加载手机的所有联系人并在ListView. 问题是，加载 400 多个联系人需要时间，这对用户来说不是很友好。谁能指出我如何让这个活动在后台运行\运行得更快，我试过使用AsyncTask但显然它使用的是一个类而不是一个活动。任何意见是极大的赞赏。
我添加了代码，以便更容易理解现在的工作方式：
这是联系人类：
public class CustomContact
{
private String contactName;
private String contactPhoneNumber;
private boolean selected = false;
public CustomContact()
{
}
public CustomContact(String contactName, String contactPhoneNumber, boolean selected)
{
super();
this.contactName = contactName;
this.contactPhoneNumber = contactPhoneNumber;
this.selected = selected;
}
public String getContactName()
{
return contactName;
}
public void setContactName(String contactName)
{
this.contactName = contactName;
}
public String getContactPhoneNumber()
{
return contactPhoneNumber;
}
public void setContactPhoneNumber(String contactPhoneNumber)
{
this.contactPhoneNumber = contactPhoneNumber;
}
public boolean isSelected()
{
return selected;
}
public void setSelected(boolean selected)
{
this.selected = selected;
}
@Override
public String toString()
{
return contactPhoneNumber + " " + "\u200e" + contactName;
}
}
现在使用CustomContacts该类的活动代码：
public class ContactSelectActivity extends Activity
{
MyCustomAdapter dataAdapter = null;
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_contact_select);
//Generate list View from ArrayList
displayListView();
checkButtonClick();
}
private void displayListView()
{
//Array list of countries
ArrayList<CustomContact> contactsList = new ArrayList<CustomContact>();
String[] projection = new String[] {ContactsContract.Contacts._ID, ContactsContract.Contacts.DISPLAY_NAME,
ContactsContract.Contacts.HAS_PHONE_NUMBER,
ContactsContract.Contacts.LOOKUP_KEY
};
String sortOrder = ContactsContract.Contacts.DISPLAY_NAME ;
ContentResolver contentResolver = getContentResolver();
Cursor cursor = contentResolver.query(ContactsContract.Contacts.CONTENT_URI, projection,
ContactsContract.Contacts.IN_VISIBLE_GROUP + " = '"+ ("1") + "'",
null, sortOrder
);
if (cursor.getCount() > 0)
{
while (cursor.moveToNext())
{
String id = cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts._ID));
String name = cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));
if (Integer.parseInt(cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts.HAS_PHONE_NUMBER))) > 0)
{
// Query phone here. Covered next
Cursor phones = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI,null,ContactsContract.CommonDataKinds.Phone.CONTACT_ID +" = "+ id,null, null);
while (phones.moveToNext())
{
String phoneNumber = phones.getString(phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
CustomContact customContact = new CustomContact(name, phoneNumber, false);
contactsList.add(customContact);
}
phones.close();
}
}
}
//create an ArrayAdaptar from the String Array
dataAdapter = new MyCustomAdapter(this,R.layout.custom_contact_info, contactsList);
ListView listView = (ListView) findViewById(R.id.listView1);
// Assign adapter to ListView
listView.setAdapter(dataAdapter);
listView.setOnItemClickListener(new OnItemClickListener()
{
public void onItemClick(AdapterView<?> parent, View view, int position, long id)
{
CustomContact contact = (CustomContact) parent.getItemAtPosition(position);
}
});
}
private class MyCustomAdapter extends ArrayAdapter<CustomContact>
{
private ArrayList<CustomContact> contactList;
public MyCustomAdapter(Context context, int textViewResourceId,
ArrayList<CustomContact> stateList)
{
super(context, textViewResourceId, stateList);
this.contactList = new ArrayList<CustomContact>();
this.contactList.addAll(stateList);
}
private class ViewHolder
{
TextView code;
CheckBox name;
}
@Override
public View getView(int position, View convertView, ViewGroup parent)
{
ViewHolder holder = null;
Log.v("ConvertView", String.valueOf(position));
if (convertView == null)
{
LayoutInflater vi = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = vi.inflate(R.layout.custom_contact_info, null);
holder = new ViewHolder();
holder.code = (TextView) convertView.findViewById(R.id.code);
holder.name = (CheckBox) convertView.findViewById(R.id.checkBox1);
convertView.setTag(holder);
holder.name.setOnClickListener( new View.OnClickListener()
{
public void onClick(View v)
{
CheckBox cb = (CheckBox) v;
CustomContact _contact = (CustomContact) cb.getTag();
_contact.setSelected(cb.isChecked());
}
});
}
else
{
holder = (ViewHolder) convertView.getTag();
}
CustomContact contact = contactList.get(position);
holder.code.setText(" (" + contact.getContactName() + ")");
holder.name.setText(contact.getContactPhoneNumber());
holder.name.setChecked(contact.isSelected());
holder.name.setTag(contact);
return convertView;
}
}
private void checkButtonClick()
{
Button myButton = (Button) findViewById(R.id.findSelected);
myButton.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v)
{
StringBuffer responseText = new StringBuffer();
responseText.append("The following were selected...\n");
ArrayList<CustomContact> contactList = dataAdapter.contactList;
for(int i=0;i<contactList.size();i++)
{
CustomContact contact = contactList.get(i);
if(contact.isSelected())
{
responseText.append("\n" + contact.getContactPhoneNumber());
}
}
}
});
}
}