我正在尝试在我的应用中设置联系人选项卡以列出用户地址簿的名称和电话号码，但是当我为联系人列表设置适配器时，应用程序不再显示其选项卡且片段为空。
代码：
package com.spgrn.smsim;
import java.util.ArrayList;
import java.util.Locale;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.app.FragmentPagerAdapter;
import android.content.ContentResolver;
import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.provider.ContactsContract;
import android.support.v4.view.ViewPager;
import android.util.Log;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
public class MainActivity extends ActionBarActivity implements ActionBar.TabListener {
/**
* The {@link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {@link FragmentPagerAdapter} derivative, which will keep every
* loaded fragment in memory. If this becomes too memory intensive, it
* may be best to switch to a
* {@link android.support.v4.app.FragmentStatePagerAdapter}.
*/
SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {@link ViewPager} that will host the section contents.
*/
ViewPager mViewPager;
String phoneNumber;
ListView contactlist;
ArrayList <String> aa= new ArrayList<String>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
contactlist= (ListView) findViewById(R.id.contactv);
getNumber(this.getContentResolver());
// Set up the action bar.
final ActionBar actionBar = getSupportActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Create the adapter that will return a fragment for each of the three
// primary sections of the activity.
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
// When swiping between different sections, select the corresponding
// tab. We can also use ActionBar.Tab#select() to do this if we have
// a reference to the Tab.
mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
@Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
});
// For each of the sections in the app, add a tab to the action bar.
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
// Create a tab with text corresponding to the page title defined by
// the adapter. Also specify this Activity object, which implements
// the TabListener interface, as the callback (listener) for when
// this tab is selected.
Log.v("I", "curtab="+ mSectionsPagerAdapter.getCount() + "i=" + i);
if (i != 1)
actionBar.addTab(
actionBar.newTab()
.setText(mSectionsPagerAdapter.getPageTitle(i))
.setTabListener(this),
false);
if (i == 1)
actionBar.addTab(
actionBar.newTab()
.setText(mSectionsPagerAdapter.getPageTitle(i))
.setTabListener(this),
true);
}
}
public void getNumber(ContentResolver cr)
{
Cursor phones = cr.query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null,null,null, null);
while (phones.moveToNext())
{
String name=phones.getString(phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));
phoneNumber = phones.getString(phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
System.out.println(name + phoneNumber);
aa.add(name + "\n" + phoneNumber);
}
Log.v("Contacts", "Total= " + phones.getCount());
phones.close();// close cursor
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1,aa);
contactlist.setAdapter(adapter);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
if (id == R.id.action_compose) {
Intent intent = new Intent(this, NewMessage.class);
this.startActivity(intent);
}
return super.onOptionsItemSelected(item);
}
@Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
// When the given tab is selected, switch to the corresponding page in
// the ViewPager.
mViewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
@Override
public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
/**
* A {@link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a PlaceholderFragment (defined as a static inner class below).
//return PlaceholderFragment.newInstance(position + 1);
switch (position){
case 0:
Fragment fragmentContacts = new FragmentContacts();
return fragmentContacts;
case 1:
Fragment fragmentMessages = new FragmentMessages();
return fragmentMessages;
case 2:
Fragment fragmentAccounts = new FragmentAccounts();
return fragmentAccounts;
}
return null;
}
@Override
public int getCount() {
// Show 5 total pages.
return 3;
}
@Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return getString(R.string.title_section1).toUpperCase(l);
case 1:
return getString(R.string.title_section2).toUpperCase(l);
case 2:
return getString(R.string.title_section3).toUpperCase(l);
}
return null;
}
}
//Make fragments for each tab
public static class FragmentContacts extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
public static final String ARG_SECTION_NUMBER = "section_number";
public FragmentContacts() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_contacts,
container, false);
return rootView;
}
}
public static class FragmentMessages extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
public static final String ARG_SECTION_NUMBER = "section_number";
public FragmentMessages() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main,
container, false);
return rootView;
}
}
public static class FragmentAccounts extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
public static final String ARG_SECTION_NUMBER = "section_number";
public FragmentAccounts() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_accounts,
container, false);
return rootView;
}
}
//End of Tab Fragments
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
private static final String ARG_SECTION_NUMBER = "section_number";
/**
* Returns a new instance of this fragment for the given section
* number.
*/
public static PlaceholderFragment newInstance(int sectionNumber) {
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle args = new Bundle();
args.putInt(ARG_SECTION_NUMBER, sectionNumber);
fragment.setArguments(args);
return fragment;
}
public PlaceholderFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
}
}
此外，在调试器中，我注意到主要活动因运行时异常而暂停。这是堆栈：
Thread [<1> main] (Suspended (exception RuntimeException))
<VM does not provide monitor information>
ActivityThread.performLaunchActivity(ActivityThread$ActivityClientRecord, Intent) line: 2195
ActivityThread.handleLaunchActivity(ActivityThread$ActivityClientRecord, Intent) line: 2245
ActivityThread.access$800(ActivityThread, ActivityThread$ActivityClientRecord, Intent) line: 135
ActivityThread$H.handleMessage(Message) line: 1196
ActivityThread$H(Handler).dispatchMessage(Message) line: 102
Looper.loop() line: 136
ActivityThread.main(String[]) line: 5017
Method.invokeNative(Object, Object[], Class, Class[], Class, int, boolean) line: not available [native method]
Method.invoke(Object, Object...) line: 515
ZygoteInit$MethodAndArgsCaller.run() line: 779
ZygoteInit.main(String[]) line: 595
XposedBridge.main(String[]) line: 126
NativeStart.main(String[]) line: not available [native method]
谢谢！
编辑：看起来更多，我认为列表需要在片段类中生成，但我不确定如何处理上下文。我一直得到一个NullPointerException。 代码：
public static class FragmentContacts extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
public static final String ARG_SECTION_NUMBER = "section_number";
public FragmentContacts() {
}
Context context;
String phoneNumber;
ListView contactlist;
ArrayList <String> aa= new ArrayList<String>();
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_contacts,
container, false);
contactlist = (ListView) rootView.findViewById(R.id.contactv);
getNumber(context.getContentResolver());
return rootView;
}
public void getNumber(ContentResolver cr)
{
Cursor phones = cr.query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null,null,null, null);
while (phones.moveToNext())
{
String name=phones.getString(phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));
phoneNumber = phones.getString(phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
System.out.println(name + phoneNumber);
aa.add(name + "\n" + phoneNumber);
}
Log.v("Contacts", "Total= " + phones.getCount());
phones.close();// close cursor
ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity()
.getApplicationContext(),
android.R.layout.simple_list_item_1,aa);
contactlist.setAdapter(adapter);
}
}
答案 0 :(得分：0)
写
context=container.getContext();
onCreateView 中的
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_contacts,
container, false);
contactlist = (ListView) rootView.findViewById(R.id.contactv);
context=container.getContext();
getNumber(context.getContentResolver());
return rootView;
}