我仍然在处理将联系人加载到listfragment中的学习活动。整个应用程序构建，我没有强制关闭，但我的列表片段不显示联系人列表。我正在使用网络上的示例，所以我确信某处存在一些不兼容性。任何帮助都会受到赞赏，因为我正在学习并试图在旅途中解决问题。
以下是我的ContactListFragment，其中<em>应该显示联系人列表：
public class ContactListFragment extends ListFragment {
private ContactAdapter mAdapter;
private List<ContactItem> contactItemList = new LinkedList<ContactItem>();
private LayoutInflater mInflater;
public boolean taskRun = false;
long currentID = 0;
long currentContactID = 0;
public ContactListFragment() {}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
mInflater = (LayoutInflater) getActivity().getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
if(!taskRun){
FragmentTransaction ft = getFragmentManager().beginTransaction();
ListContactTask task= new ListContactTask(getActivity(),ft);
task.execute();
}
taskRun = true;
mAdapter = new ContactAdapter(getActivity(), R.layout.lvmain,R.id.key, contactItemList);
mAdapter .setInflater(mInflater);
mAdapter.setLayout(R.layout.contact_card);
setListAdapter(mAdapter);
ListView listView = getListView();
getListView().invalidate();
}
public void setDataList( List<ContactItem> list) {
Activity act = getActivity();
this.contactItemList = list;
if(act != null) {
mAdapter = new ContactAdapter(act, R.layout.lvmain,R.id.key, list);
mAdapter .setInflater(mInflater);
mAdapter.setLayout(R.layout.contact_card);
setListAdapter(mAdapter );
getListView().invalidate();
}
}
}
class ContactAdapter extends ArrayAdapter<ContactItem> {
private static String TAG = ContactAdapter.class.getName();
private LayoutInflater inflator = null;
List<ContactItem> pairList = null;
private int layout;
public ContactAdapter(Context context, int resource,
int textViewResourceId, List<ContactItem> objects) {
super(context, resource, textViewResourceId, objects);
this.pairList = objects;
}
public void setInflater(LayoutInflater mInflater) {
this.inflator = mInflater;
}
public void setLayout(int layout){
this.layout = layout;
}
/**
* Make a view to hold each row.
*
* @see android.widget.ListAdapter#getView(int, android.view.View,
* android.view.ViewGroup)
*/
public View getView(final int position, View convertView,
ViewGroup parent) {
ViewHolder holder;
try {
if (convertView == null) {
convertView = this.inflator.inflate(
layout, null);
holder = new ViewHolder();
holder.key = (TextView) convertView
.findViewById(R.id.key);
holder.value = (TextView) convertView.findViewById(R.id.value);
convertView.setTag(holder);
}else {
holder = (ViewHolder) convertView.getTag();
}
ContactItem pair = (ContactItem) getItem(position);
String key = pair.mDisplayName;
String value = pair.mPhone;
holder.key.setText(key);
holder.value.setText(value);
Log.i("pairing", "happened");
} catch (Exception e) {
Log.e(TAG, e.toString(), e);
}
return convertView;
}
static class ViewHolder {
TextView key;
TextView value;
}
public Filter getFilter() {
return null;
}
public long getItemId(int position) {
return 1;
}
public int getCount() {
return pairList.size();
}
public ContactItem getItem(int position) {
return (ContactItem) super.getItem(position);
}
@Override
public int getItemViewType(int position) {
return super.getItemViewType(position);
}
@Override
public int getViewTypeCount() {
return super.getViewTypeCount();
}
@Override
public boolean isEmpty() {
return super.isEmpty();
}
}
这是列表联系人任务（来自我正在使用的示例）。我注释掉了onPostExecute，因为它导致了我的错误，所以我猜这是我的问题。问题是我不知道如何在我的ContactListFragment中加入onPostExecute的接收器。
import android.app.Activity;
import android.support.v4.app.FragmentTransaction;
import android.database.Cursor;
import android.os.AsyncTask;
import android.provider.ContactsContract.Data;
import android.provider.ContactsContract.CommonDataKinds.Phone;
import android.util.Log;
public class ListContactTask extends AsyncTask<Void, Void, List<ContactItem>> {
private FragmentTransaction ft;
private Activity activity;
public ListContactTask(Activity activity, FragmentTransaction ft) {
this.activity = activity;
this.ft = ft;
}
public ListContactTask() {
}
@SuppressWarnings("unused")
protected List<ContactItem> doInBackground(Void... params) {
Cursor c = activity.getContentResolver().query(Data.CONTENT_URI,
new String[] {Data._ID, Data.DISPLAY_NAME,Phone.NUMBER, Data.CONTACT_ID,Phone.TYPE, Phone.LABEL},
Data.MIMETYPE + "='" + Phone.CONTENT_ITEM_TYPE + "'",
null,
Data.DISPLAY_NAME);
int count = c.getCount();
boolean b = c.moveToFirst();
String[] columnNames = c.getColumnNames();
int displayNameColIndex = c.getColumnIndex("display_name");
int idColIndex = c.getColumnIndex("_id");
//int contactIdColIndex = c.getColumnIndex("contact_id");
int col2Index = c.getColumnIndex(columnNames[2]);
int col3Index = c.getColumnIndex(columnNames[3]);
int col4Index = c.getColumnIndex(columnNames[4]);
List<ContactItem> contactItemList = new LinkedList<ContactItem>();
for(int i = 0; i < count ; i ++) {
String displayName = c.getString(displayNameColIndex);
String phoneNumber = c.getString(col2Index);
int contactId = c.getInt(col3Index);
String phoneType = c.getString(col4Index);
long _id = c.getLong(idColIndex);
ContactItem contactItem = new ContactItem();
contactItem.mId= _id;
contactItem.mContactId = contactId;
contactItem.mDisplayName = displayName;
contactItem.mPhone = phoneNumber;
contactItemList.add(contactItem);
boolean b2 = c.moveToNext();
}
c.close();
return contactItemList;
}
/*
protected void onPostExecute(List<ContactItem> result) {
((MainActivity)activity).addContactListFragment(ft, result);
}
*/
}
这也是我的布局文件：
Contact_card.xml：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="#ffe6e6e6" >
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="4dp"
android:layout_marginLeft="10dp"
android:layout_marginRight="10dp"
android:layout_marginTop="2dp"
android:background="@drawable/card_background"
android:orientation="horizontal" >
<LinearLayout
android:id="@+id/contactImage"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_marginRight="5dip"
android:background="@drawable/ic_contact"
android:orientation="horizontal"
android:padding="3dip" >
</LinearLayout>
<TextView
android:id="@+id/key"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignTop="@+id/contactImage"
android:layout_toRightOf="@+id/contactImage"
android:text="TestNameHere"
android:textColor="@color/card_text"
android:textSize="@dimen/contact_name"
android:textStyle="bold"
android:typeface="sans"
tools:ignore="HardcodedText" />
<TextView
android:id="@+id/value"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_below="@id/key"
android:layout_marginTop="3dip"
android:layout_toRightOf="@+id/contactImage"
android:text="800-867-5309"
android:textColor="@color/card_text"
android:textSize="@dimen/contact_phone"
tools:ignore="HardcodedText" />
</RelativeLayout>
</LinearLayout>
lvmain.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="fill_parent"
android:orientation="vertical" >
<ListView
android:id="@+id/list"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:cacheColorHint="#00000000"
android:divider="#00000000" />
</RelativeLayout>
我希望这一切都有道理，而且我不只是漫无边际地走错路。
编辑：
也有助于包含我的MainActivity：
public class MainActivity extends FragmentActivity implements
ActionBar.TabListener {
private ViewPager viewPager;
private TabsPagerAdapter mAdapter;
private ActionBar actionBar;
// Tab titles
private String[] tabs = { "Quick Actions", "Contacts", "Apps" };
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu items for use in the action bar
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.main, menu);
return super.onCreateOptionsMenu(menu);
}
@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_search) {
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Initilization
viewPager = (ViewPager) findViewById(R.id.pager);
actionBar = getActionBar();
mAdapter = new TabsPagerAdapter(getSupportFragmentManager());
viewPager.setAdapter(mAdapter);
actionBar.setHomeButtonEnabled(false);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Adding Tabs
for (String tab_name : tabs) {
actionBar.addTab(actionBar.newTab().setText(tab_name)
.setTabListener(this));
}
/**
* on swiping the viewpager make respective tab selected
* */
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageSelected(int position) {
// on changing the page
// make respected tab selected
actionBar.setSelectedNavigationItem(position);
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
@Override
public void onPageScrollStateChanged(int arg0) {
}
});
}
@Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}
@Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
// on tab selected
// show respected fragment view
viewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
}
}
编辑2： 我已做出如下所述的修改，但现在收到此错误：
The method setDataList(List<ContactItem>) in the type ContactListFragment is not applicable for the arguments ()
这是我更新的ListContact.java：
import com.nmiltner.slidedialer.free.data.ContactItem;
import com.nmiltner.slidedialer.free.ContactListFragment;
import com.nmiltner.slidedialer.free.MainActivity;
public class ListContactTask extends AsyncTask<Void, Void, List<ContactItem>> {
private FragmentTransaction ft;
private Activity activity;
public ListContactTask(Activity activity, FragmentTransaction ft) {
this.activity = activity;
this.ft = ft;
}
public ListContactTask() {
}
@SuppressWarnings("unused")
protected List<ContactItem> doInBackground(Void... params) {
Cursor c = activity.getContentResolver().query(Data.CONTENT_URI,
new String[] {Data._ID, Data.DISPLAY_NAME,Phone.NUMBER, Data.CONTACT_ID,Phone.TYPE, Phone.LABEL},
Data.MIMETYPE + "='" + Phone.CONTENT_ITEM_TYPE + "'",
null,
Data.DISPLAY_NAME);
int count = c.getCount();
boolean b = c.moveToFirst();
String[] columnNames = c.getColumnNames();
int displayNameColIndex = c.getColumnIndex("display_name");
int idColIndex = c.getColumnIndex("_id");
//int contactIdColIndex = c.getColumnIndex("contact_id");
int col2Index = c.getColumnIndex(columnNames[2]);
int col3Index = c.getColumnIndex(columnNames[3]);
int col4Index = c.getColumnIndex(columnNames[4]);
List<ContactItem> contactItemList = new LinkedList<ContactItem>();
for(int i = 0; i < count ; i ++) {
String displayName = c.getString(displayNameColIndex);
String phoneNumber = c.getString(col2Index);
int contactId = c.getInt(col3Index);
String phoneType = c.getString(col4Index);
long _id = c.getLong(idColIndex);
ContactItem contactItem = new ContactItem();
contactItem.mId= _id;
contactItem.mContactId = contactId;
contactItem.mDisplayName = displayName;
contactItem.mPhone = phoneNumber;
contactItemList.add(contactItem);
boolean b2 = c.moveToNext();
}
c.close();
return contactItemList;
}
protected void onPostExecute(List<ContactItem> result) {
ContactListFragment.setDataList();
}
}
和我的ContactListFragment：
public class ContactListFragment extends ListFragment {
private ContactAdapter mAdapter;
private List<ContactItem> contactItemList = new LinkedList<ContactItem>();
private LayoutInflater mInflater;
public boolean taskRun = false;
long currentID = 0;
long currentContactID = 0;
public ContactListFragment() {}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
mInflater = (LayoutInflater) getActivity().getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
if(!taskRun){
FragmentTransaction ft = getFragmentManager().beginTransaction();
ListContactTask task= new ListContactTask(getActivity(),ft);
task.execute();
}
taskRun = true;
mAdapter = new ContactAdapter(getActivity(), R.layout.lvmain,R.id.key, contactItemList);
mAdapter .setInflater(mInflater);
mAdapter.setLayout(R.layout.contact_card);
setListAdapter(mAdapter);
ListView listView = getListView();
getListView().invalidate();
}
public void setDataList( List<ContactItem> list) {
Activity act = getActivity();
this.contactItemList = list;
if(act != null) {
mAdapter = new ContactAdapter(act, R.layout.lvmain,R.id.key, list);
mAdapter .setInflater(mInflater);
mAdapter.setLayout(R.layout.contact_card);
setListAdapter(mAdapter );
getListView().invalidate();
}
}
}
class ContactAdapter extends ArrayAdapter<ContactItem> {
private static String TAG = ContactAdapter.class.getName();
private LayoutInflater inflator = null;
List<ContactItem> pairList = null;
private int layout;
public ContactAdapter(Context context, int resource,
int textViewResourceId, List<ContactItem> objects) {
super(context, resource, textViewResourceId, objects);
this.pairList = objects;
}
public void setInflater(LayoutInflater mInflater) {
this.inflator = mInflater;
}
public void setLayout(int layout){
this.layout = layout;
}
/**
* Make a view to hold each row.
*
* @see android.widget.ListAdapter#getView(int, android.view.View,
* android.view.ViewGroup)
*/
public View getView(final int position, View convertView,
ViewGroup parent) {
ViewHolder holder;
try {
if (convertView == null) {
convertView = this.inflator.inflate(
layout, null);
holder = new ViewHolder();
holder.key = (TextView) convertView
.findViewById(R.id.key);
holder.value = (TextView) convertView.findViewById(R.id.value);
convertView.setTag(holder);
}else {
holder = (ViewHolder) convertView.getTag();
}
ContactItem pair = (ContactItem) getItem(position);
String key = pair.mDisplayName;
String value = pair.mPhone;
holder.key.setText(key);
holder.value.setText(value);
Log.i("pairing", "happened");
} catch (Exception e) {
Log.e(TAG, e.toString(), e);
}
return convertView;
}
static class ViewHolder {
TextView key;
TextView value;
}
public Filter getFilter() {
return null;
}
public long getItemId(int position) {
return 1;
}
public int getCount() {
return pairList.size();
}
public ContactItem getItem(int position) {
return (ContactItem) super.getItem(position);
}
@Override
public int getItemViewType(int position) {
return super.getItemViewType(position);
}
@Override
public int getViewTypeCount() {
return super.getViewTypeCount();
}
@Override
public boolean isEmpty() {
return super.isEmpty();
}
}
答案 0 :(得分：0)
您的AsyncTask可能在您调用ContactListFragment.setListAdapter()之前尚未完成工作，因此它可能首先处于空白状态。在ContactListFragment.setDataList()方法中处理您的UI更改（调用AsyncTask.onPostExecute()），这样您就可以确保AsyncTask完成并填充适配器。
修改：如果您想要特定的AsyncTask.onPostExecute()，可以在ContactListFragment中覆盖它：
ListContactTask task = new ListContactTask () {
protected void onPostExecute(List<ContactItem> result) {
// do specific stuff here, eg:
ContactListFragment.this.setDataList(result);
}
};
// Do other stuff