问题
I'm working on showing list of contacts with checkbox. I tried implementing my own cursor adapter and it is checkable. But once I check that value I want the contacts to be stored in ContactPerson object. But when I tried it is showing null pointer exception(That's why I commented out that code). My CursorAdapter code goes like this.
ContactListAcitivity.java
import android.app.Activity;
import android.content.Context;
import android.database.Cursor;
import android.os.Bundle;
import android.provider.ContactsContract;
import android.support.v4.widget.CursorAdapter;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CheckBox;
import android.widget.ListView;
import android.widget.TextView;
public class ContactListActivity extends Activity {
ListView list;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_contact_list);
list = (ListView) findViewById(R.id.ListView2);
Cursor cur= getContentResolver().query(ContactsContract.Contacts.CONTENT_URI, null,null,null,null);
startManagingCursor(cur);
String[] result=new String[cur.getCount()];
for (boolean hasData = cur.moveToFirst(); hasData; hasData = cur.moveToNext())
{
ContactPerson contact = new ContactPerson(cur.getString(cur.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME)), String.valueOf(cur.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER)));
}
stopManagingCursor(cur);
list.setAdapter(new contactAdapter(getApplicationContext(), cur));
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.contact_list, menu);
return true;
}
private class ViewHolder{
TextView ContactName;
CheckBox contactCheck;
}
class contactAdapter extends CursorAdapter{
private Cursor cursor;
private Context ccontext;
private LayoutInflater inflater;
public contactAdapter(Context context, Cursor c) {
super(context, c);
// TODO Auto-generated constructor stub
cursor = c;
ccontext = context;
inflater = LayoutInflater.from(context);
inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@Override
public void bindView(View view, Context arg1, Cursor arg2) {
// TODO Auto-generated method stub
ViewHolder holder = (ViewHolder) view.getTag();
if (holder == null) {
holder = new ViewHolder();
holder.ContactName = (TextView) view.findViewById(R.id.contact_name);
holder.contactCheck = (CheckBox) view.findViewById(R.id.contact_check);
view.setTag(holder);
holder.contactCheck.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
CheckBox cb = (CheckBox) v;
cb.setSelected(true);
// ContactPerson contact = (ContactPerson) cb.getTag(); this is the place where it is showing null pointer exception
// Log.i("clicked users", contact.getName());
// contact.setSelected(true);
}
});
}else{
holder = (ViewHolder) view.getTag();
}
// ContactPerson contacts = contactList.get(position);
holder.ContactName.setText(cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME)));
// holder.contactCheck.setChecked(contacts.isSelected());
// holder.contactCheck.setTag(contacts);
// holder.ContactName.setText(contacts.getName());
}
@Override
public View newView(Context arg0, Cursor arg1, ViewGroup arg2) {
// TODO Auto-generated method stub
return inflater.inflate(R.layout.checkbox_item, arg2, false);
}
}
}
activity_contact_list.xml
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#000000">
<ListView
android:id="@+id/ListView2"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".GroupContactsActivity"
android:layout_alignParentTop="true"
/>
<Button
android:id="@+id/selected_done_1"
android:layout_width="160dp"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:textColor="#FFFFFF"
android:text="Done" />
</RelativeLayout>
checkbox_item.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="6dip"
android:background="#000000">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/contact_name"
android:layout_alignParentLeft="true"
android:text="textview"
android:textSize="15sp"
android:textColor="#FFFFFF"
android:gravity="center_horizontal"/>
<CheckBox
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:focusable="false"
android:focusableInTouchMode="false"
android:layout_alignParentRight="true"
android:layout_weight="1"
android:id="@+id/contact_check"/>
</RelativeLayout>
Can anyone please suggest me how to use that Contact person class in this adapter.
public class ContactPerson {
String name= null, number = null;
boolean Selected = false;
public ContactPerson(String PersonName, String PhoneNumber){
this.name = PersonName;
this.number= PhoneNumber;
}
public String getName(){
return name;
}
public boolean isSelected(){
return Selected;
}
public void setSelected(boolean selected){
this.Selected = selected;
}
public String getPhoneNumber(){
return number;
}
}
回答1:
Check this code. It worked for me. Best of luck.
import java.util.ArrayList;
import java.util.Set;
import java.util.TreeSet;
import android.app.Activity;
import android.content.Context;
import android.database.Cursor;
import android.os.Bundle;
import android.provider.ContactsContract;
import android.support.v4.widget.CursorAdapter;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
public class ContactListActivity extends Activity {
ListView list;
ArrayList<ContactPerson> selectedList;
Set<String> phoneID= new TreeSet<String>();;
Button doneButton;
CheckBox cb;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_contact_list);
selectedList = new ArrayList<ContactPerson>();
list = (ListView) findViewById(R.id.ListView2);
doneButton = (Button) findViewById(R.id.selected_done_1);
Cursor cur= getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null,null,null,null);
list.setAdapter(new contactAdapter(getApplicationContext(), cur));
doneButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
for (String ids : phoneID) {
Log.d("PhoneIds", ids);
Cursor cursorPhoneNumber = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI,
new String[]{ContactsContract.CommonDataKinds.Phone.NUMBER},
ContactsContract.CommonDataKinds.Phone.CONTACT_ID + " = ? AND " +
ContactsContract.CommonDataKinds.Phone.TYPE + " = " +
ContactsContract.CommonDataKinds.Phone.TYPE_MOBILE,
new String[]{ids},
null);
Log.d("Number cursor", String.valueOf(cursorPhoneNumber.getCount()));
if (cursorPhoneNumber.moveToFirst()) {
// phoneNumber = cursorPhoneNumber.getString(cursorPhoneNumber.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
Log.d("Phone number", cursorPhoneNumber.getString(cursorPhoneNumber.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER)));
}
cursorPhoneNumber.close();
Cursor cursorName = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI,
new String[]{ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME_PRIMARY},
ContactsContract.CommonDataKinds.Phone.CONTACT_ID + " = ? AND " +
ContactsContract.CommonDataKinds.Phone.TYPE + " = " +
ContactsContract.CommonDataKinds.Phone.TYPE_MOBILE,
new String[]{ids},
null);
Log.d("Name cursor", String.valueOf(cursorName.getCount()));
if (cursorName.moveToFirst()) {
Log.d("Phone number", cursorName.getString(cursorName.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME_PRIMARY)));
// Name = cursorName.getString(cursorName.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME_PRIMARY));
}
cursorName.close();
// selectedList.add(new ContactPerson(Name,phoneNumber));
}
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.contact_list, menu);
return true;
}
private class ViewHolder{
TextView ContactName;
CheckBox contactCheck;
}
class contactAdapter extends CursorAdapter{
String Name, phoneNumber;
private Cursor cursor;
private Context ccontext;
private LayoutInflater inflater;
public contactAdapter(Context context, Cursor c) {
super(context, c);
// TODO Auto-generated constructor stub
cursor = c;
ccontext = context;
inflater = LayoutInflater.from(context);
inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@Override
public void bindView(View view, Context arg1, Cursor arg2) {
// TODO Auto-generated method stub
ViewHolder holder = (ViewHolder) view.getTag();
if (holder == null) {
holder = new ViewHolder();
holder.ContactName = (TextView) view.findViewById(R.id.contact_name);
holder.contactCheck = (CheckBox) view.findViewById(R.id.contact_check);
view.setTag(holder);
holder.contactCheck.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
cb = (CheckBox) v;
cb.setChecked(cb.isChecked());
// ContactPerson selected = (ContactPerson)cb.getTag();
Log.d("selcted", cb.getTag().toString());
if(cb.isChecked()){
phoneID.add(cb.getTag().toString());
}
}
});
}else{
holder = (ViewHolder) view.getTag();
}
holder.ContactName.setText(cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME)));
holder.contactCheck.setTag(cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.CONTACT_ID)));
holder.contactCheck.setChecked(false);
}
@Override
public View newView(Context arg0, Cursor arg1, ViewGroup arg2) {
// TODO Auto-generated method stub
return inflater.inflate(R.layout.checkbox_item, arg2, false);
}
@Override
public View getView(int arg0, View arg1, ViewGroup arg2) {
// TODO Auto-generated method stub
// Log.d("don't know", cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER)));
return super.getView(arg0, arg1, arg2);
}
}
}
回答2:
Here i changed little bit code of your adapter and activity. just look at it:
public class MainActivity extends Activity {
private ArrayList<ContactPerson> arr;
private Context context;
private ListView list;
private ContactArrayAdapter adapter;
private String strName,strNumber;
private View view;
public static boolean[] arrBoolean = null;
@Override
public void onCreate(Bundle savedInstance) {
super.onCreate(savedInstance);
setContentView(R.layout.activity_main);
ProgressDialog pd = new ProgressDialog(this);
list = (ListView)findViewById(R.id.ListView2);
arr = new ArrayList<ContactPerson>();
context = MainActivity.this;
arr = displayContacts();
adapter = new ContactArrayAdapter(this, R.layout.checkbox_item, arr);
list.setAdapter(adapter);
}
public ArrayList<ContactPerson> displayContacts() {
ContentResolver cr = getContentResolver();
Cursor cur = cr.query(ContactsContract.Contacts.CONTENT_URI,null, null, null, null);
ContactPerson contact;
if (cur.getCount() > 0) {
while (cur.moveToNext()) {
contact = new ContactPerson();
String id = cur.getString(cur.getColumnIndex(People._ID));
String name = cur.getString(cur.getColumnIndex(People.DISPLAY_NAME));
ContactPerson cp = new ContactPerson();
cp.setName(name);
cp.setNumber(id);
cp.setSelected(false);
arr.add(cp);
}
}
return arr;
}
//********* Adapter *****
public class ContactArrayAdapter extends ArrayAdapter<ContactPerson> {
// private final List<Contact> list;
private Context context;
private LayoutInflater mInflater;
private List<ContactPerson> list;
public ContactArrayAdapter(Context context, int textViewResourceId,
ArrayList<ContactPerson> stateList) {
super(context, textViewResourceId, stateList);
this.list = new ArrayList<ContactPerson>();
this.list.addAll(stateList);
}
class ViewHolder {
TextView text;
CheckBox checkbox;
}
public View getView(int position, View convertView, ViewGroup parent) {
View view = convertView;
ViewHolder viewHolder = null;
if (view == null) {
LayoutInflater vi = (LayoutInflater)getSystemService(
Context.LAYOUT_INFLATER_SERVICE);
view = vi.inflate(R.layout.checkbox_item, null);
viewHolder = new ViewHolder();
viewHolder.text = (TextView) view.findViewById(R.id.contact_name);
viewHolder.checkbox = (CheckBox) view.findViewById(R.id.contact_check);
view.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) view.getTag();
}
final int pos = position;
ContactPerson cp = list.get(position);
viewHolder.text.setText(cp.getName());
viewHolder.checkbox.setChecked(cp.isSelected());
viewHolder.checkbox.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
CheckBox cb = (CheckBox) arg0 ;
list.get(pos).setSelected(cb.isChecked());
System.out.println(cb.isChecked());
System.out.println(list.get(pos).getName());
}
});
//viewHolder.text.setTag(cp);
return view;
}
}
}
来源：https://stackoverflow.com/questions/20699062/assinging-the-values-of-cursor-to-object