在我的 Android 中，我正在使用内容解析器读取联系人。但是内容解析器没有初始化，它给出了 NullPointerException 。
我想在另一个类中使用字符串数组并获取其中的值我必须查询数据库并从电话中读取联系人，但是如代码中指出的那样，遇到了该异常:
//this code is in some other class...
et= (EditText) findViewById(R.id.searchcontact);
et.addTextChangedListener(new TextWatcher() {
public void onTextChanged(CharSequence s, int start, int before, int
count) { // TODO Auto-generated method stub
lva.getFilter().filter(s);
RefreshListView rlv=new RefreshListView();<----class is getting called from here
lva.notifyDataSetInvalidated();
lva = new ListViewAdapterContacts(AllContactsActivity.this, rlv.names, rlv.types, rlv.phones, rlv.ids);
lv.setAdapter(lva);
}
public void beforeTextChanged(CharSequence s, int start, int count,
int after) { // TODO Auto-generated method stub
}
public void afterTextChanged(Editable s) {
// TODO Auto-generated method stub
// lva.notifyDataSetChanged();
}
});
...............********.........
public class RefreshListView extends ListActivity{
String[] names,phones,types,ids;
String name,id,phoneNumber;
int type;
ArrayList <String> newValues;
public void onCreate(Bundle b){
super.onCreate(b);
newValues=SetNewList.getNames();
getContacts();
}
public void getContacts(){
int foo = 0;
ContentResolver cr = getContentResolver();<---//null pointer exception
Cursor cur = cr.query(ContactsContract.Contacts.CONTENT_URI, null,
null, null, "UPPER(" + ContactsContract.Contacts.DISPLAY_NAME
+ ") ASC");
if (cur.getCount() > 0) {
names = new String[cur.getCount()];
phones = new String[cur.getCount()];
types = new String[cur.getCount()];
ids = new String[cur.getCount()];
while (cur.moveToNext()) {
name = cur
.getString(cur
.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));
for(int i=0;i<=newValues.size();i++){
if(newValues.get(i).equalsIgnoreCase(name)) {
id = cur.getString(cur
.getColumnIndex(ContactsContract.Contacts._ID));
String hasPhone = cur
.getString(cur
.getColumnIndex(ContactsContract.Contacts.HAS_PHONE_NUMBER));
if (Integer.parseInt(hasPhone) == 1) {
Cursor phones = getContentResolver().query(
ContactsContract.CommonDataKinds.Phone.CONTENT_URI,
null,
ContactsContract.CommonDataKinds.Phone.CONTACT_ID
+ " = " + id, null, null);
while (phones.moveToNext()) {
phoneNumber = phones
.getString(phones
.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
type = phones.getInt(phones.getColumnIndex(Phone.TYPE));
} // while
phones.close();
}// if
else {
phoneNumber = "unknown";
type = 0;
}// else
phones[foo] = phoneNumber;
names[foo] = name;
ids[foo] = id;
if (type == 0) {
String value = "unknown";
types[foo] = value;
}
else if (type == 1) {
String value = "home";
types[foo] = value;
}// if
else if (type == 2) {
String value = "mobile";
types[foo] = value;
}// else if
else if (type == 3) {
String value = "Work";
types[foo] = value;
}
else if (type == 4) {
String value = "Workfax";
types[foo] = value;
}
else if (type == 5) {
String value = "Home Fax";
types[foo] = value;
} else if (type == 6) {
String value = "Pager";
types[foo] = value;
}
else {
String value = "Other";
types[foo] = value;
}
foo++;
}
}
}// while
}// if
}// get contacts
}
最佳答案
不要这样做...
public class RefreshListView extends ListActivity{
public RefreshListView() {
...
}
}
不要为 Android
Activity 使用构造函数!!!您应该删除该构造函数并将代码放入
Activity onCreate(...) 方法中。请参阅 Activity 的文档并阅读 Activities 。
尝试这样的事情......
public class RefreshListView extends ListActivity{
String[] names,phones,types,ids;
String name,id,phoneNumber;
int type;
ArrayList <String> newValues;
ContentResolver cr = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
cr = getContentResolver();
newValues=SetNewList.getNames();//getnames is of static type
getContacts();
}
public void getContacts() {
int foo = 0;
// REMOVE THE NEXT LINE !!!
// ContentResolver cr = getContentResolver();
...
}
}
关于java - 实例化内容解析器时出现空指针异常？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/8399607/