在这种情况下非常需要帮助...我有一个片段，使用sQLite加载数据库适配器...并调用一个方法，将SQLite数据库中的数据显示到我的片段布局中的listview ...
这是错误
11-17 19:22:36.659: D/jdwp(29500): sendBufferedRequest : len=0x37
11-17 19:22:36.673: W/asset(29500): AssetManager-->addDefaultAssets CIP path not exsit!
11-17 19:22:36.956: D/dalvikvm(29500): GC_FOR_ALLOC freed 40K, 9% free 2625K/2860K, paused 28ms, total 28ms
11-17 19:22:36.957: I/dalvikvm-heap(29500): Grow heap (frag case) to 4.216MB for 1536016-byte allocation
11-17 19:22:36.968: D/dalvikvm(29500): GC_FOR_ALLOC freed <1K, 6% free 4125K/4364K, paused 11ms, total 11ms
11-17 19:22:37.126: D/dalvikvm(29500): GC_FOR_ALLOC freed 1K, 6% free 4127K/4364K, paused 9ms, total 9ms
11-17 19:22:37.127: I/dalvikvm-heap(29500): Grow heap (frag case) to 14.131MB for 10394224-byte allocation
11-17 19:22:37.141: D/dalvikvm(29500): GC_FOR_ALLOC freed <1K, 2% free 14277K/14516K, paused 14ms, total 14ms
11-17 19:22:37.406: V/PhoneWindow(29500): DecorView setVisiblity: visibility = 4
11-17 19:22:37.419: V/PhoneWindow(29500): DecorView setVisiblity: visibility = 0
11-17 19:22:37.521: D/libEGL(29500): loaded /system/lib/egl/libEGL_mali.so
11-17 19:22:37.527: D/libEGL(29500): loaded /system/lib/egl/libGLESv1_CM_mali.so
11-17 19:22:37.531: D/libEGL(29500): loaded /system/lib/egl/libGLESv2_mali.so
11-17 19:22:37.565: D/OpenGLRenderer(29500): Enabling debug mode 0
11-17 19:22:37.570: V/InputMethodManager(29500): onWindowFocus: null softInputMode=288 first=true flags=#1810100
11-17 19:22:37.570: V/InputMethodManager(29500): START INPUT: com.android.internal.policy.impl.PhoneWindow$DecorView{41de2868 V.E..... R.....ID 0,0-480,800} ic=null tba=android.view.inputmethod.EditorInfo@41de45c8 controlFlags=#104
11-17 19:22:37.587: V/InputMethodManager(29500): Starting input: Bind result=InputBindResult{null com.cootek.smartinputv5.oem/com.cootek.smartinput5.TouchPalIME #689}
11-17 19:22:37.742: I/InputMethodManager(29500): handleMessage: MSG_SET_ACTIVE true, was false
11-17 19:22:42.013: D/AbsListView(29500): checkAbsListViewlLogProperty get invalid command
11-17 19:22:42.070: V/PhoneWindow(29500): DecorView setVisiblity: visibility = 4
11-17 19:22:42.080: V/PhoneWindow(29500): DecorView setVisiblity: visibility = 0
11-17 19:22:42.721: V/InputMethodManager(29500): onWindowFocus: android.support.v4.widget.DrawerLayout{42964600 VFE..... .F....I. 0,0-480,690 #7f070014 app:id/drawer_layout} softInputMode=288 first=true flags=#1810100
11-17 19:22:42.722: V/InputMethodManager(29500): START INPUT: android.support.v4.widget.DrawerLayout{42964600 VFE..... .F....I. 0,0-480,690 #7f070014 app:id/drawer_layout} ic=null tba=android.view.inputmethod.EditorInfo@42aa0110 controlFlags=#105
11-17 19:22:42.764: V/InputMethodManager(29500): Starting input: Bind result=InputBindResult{com.android.internal.view.IInputMethodSession$Stub$Proxy@42aa0b00 com.cootek.smartinputv5.oem/com.cootek.smartinput5.TouchPalIME #690}
11-17 19:22:42.833: D/OpenGLRenderer(29500): Flushing caches (mode 0)
11-17 19:22:43.132: D/OpenGLRenderer(29500): Flushing caches (mode 0)
11-17 19:22:44.176: I/SurfaceTextureClient(29500): [STC::queueBuffer] (this:0x519125d0) fps:1.35, dur:1482.56, max:1346.10, min:136.46
11-17 19:22:44.219: V/Provider/Settings(29500): invalidate [system]: current 23 != cached 0
11-17 19:22:44.257: D/ActivityThread(29500): installProvider: context=android.app.ContextImpl@42948878holder=android.app.IActivityManager$ContentProviderHolder@42aa2780noisy=truenoReleaseNeeded=truestable=true
11-17 19:22:44.260: V/Provider/Settings(29500): from db cache, name = sound_effects_enabled , value = 0
11-17 19:22:45.543: I/SurfaceTextureClient(29500): [STC::queueBuffer] (this:0x519125d0) fps:13.90, dur:1367.11, max:824.16, min:9.13
11-17 19:22:45.577: D/VelocityTracker(29500): VelocityTracker: int datax = 10
11-17 19:22:45.577: D/VelocityTracker(29500): VelocityTracker: int m_velocity_magnify_x = 1.000000
11-17 19:22:45.577: D/VelocityTracker(29500): VelocityTracker: int datay = 10
11-17 19:22:45.577: D/VelocityTracker(29500): VelocityTracker: int m_velocity_magnify_y = 1.000000
11-17 19:22:45.578: D/VelocityTracker(29500): VelocityTracker: int datax = 10
11-17 19:22:45.578: D/VelocityTracker(29500): VelocityTracker: int m_velocity_magnify_x = 1.000000
11-17 19:22:45.578: D/VelocityTracker(29500): VelocityTracker: int datay = 10
11-17 19:22:45.578: D/VelocityTracker(29500): VelocityTracker: int m_velocity_magnify_y = 1.000000
11-17 19:22:45.603: D/VelocityTracker(29500): VelocityTracker: int datax = 10
11-17 19:22:45.604: D/VelocityTracker(29500): VelocityTracker: int m_velocity_magnify_x = 1.000000
11-17 19:22:45.604: D/VelocityTracker(29500): VelocityTracker: int datay = 10
11-17 19:22:45.604: D/VelocityTracker(29500): VelocityTracker: int m_velocity_magnify_y = 1.000000
11-17 19:22:45.696: V/Provider/Settings(29500): from settings cache , name = sound_effects_enabled , value = 0
11-17 19:22:45.910: D/AbsListView(29500): checkAbsListViewlLogProperty get invalid command
11-17 19:22:46.007: W/DbAdapater(29500): 1
11-17 19:22:46.042: D/AndroidRuntime(29500): Shutting down VM
11-17 19:22:46.042: W/dalvikvm(29500): threadid=1: thread exiting with uncaught exception (group=0x41b2b9a8)
11-17 19:22:46.068: E/AndroidRuntime(29500): FATAL EXCEPTION: main
11-17 19:22:46.068: E/AndroidRuntime(29500): java.lang.NullPointerException
11-17 19:22:46.068: E/AndroidRuntime(29500): at com.hanapp.gps.MyPlaces.displayListView(MyPlaces.java:100)
11-17 19:22:46.068: E/AndroidRuntime(29500): at com.hanapp.gps.MyPlaces.onCreateView(MyPlaces.java:59)
11-17 19:22:46.068: E/AndroidRuntime(29500): at android.app.Fragment.performCreateView(Fragment.java:1701)
11-17 19:22:46.068: E/AndroidRuntime(29500): at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:885)
11-17 19:22:46.068: E/AndroidRuntime(29500): at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1057)
11-17 19:22:46.068: E/AndroidRuntime(29500): at android.app.BackStackRecord.run(BackStackRecord.java:694)
11-17 19:22:46.068: E/AndroidRuntime(29500): at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1435)
11-17 19:22:46.068: E/AndroidRuntime(29500): at android.app.FragmentManagerImpl$1.run(FragmentManager.java:441)
11-17 19:22:46.068: E/AndroidRuntime(29500): at android.os.Handler.handleCallback(Handler.java:800)
11-17 19:22:46.068: E/AndroidRuntime(29500): at android.os.Handler.dispatchMessage(Handler.java:100)
11-17 19:22:46.068: E/AndroidRuntime(29500): at android.os.Looper.loop(Looper.java:194)
11-17 19:22:46.068: E/AndroidRuntime(29500): at android.app.ActivityThread.main(ActivityThread.java:5400)
11-17 19:22:46.068: E/AndroidRuntime(29500): at java.lang.reflect.Method.invokeNative(Native Method)
11-17 19:22:46.068: E/AndroidRuntime(29500): at java.lang.reflect.Method.invoke(Method.java:525)
11-17 19:22:46.068: E/AndroidRuntime(29500): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:837)
11-17 19:22:46.068: E/AndroidRuntime(29500): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:604)
11-17 19:22:46.068: E/AndroidRuntime(29500): at dalvik.system.NativeStart.main(Native Method)
这是我的establishment_info xml布局
<?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" >
<TextView
android:id="@+id/name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:text="TextView"
android:textAppearance="?android:attr/textAppearanceMedium" />
<TextView
android:id="@+id/address"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/name"
android:text="TextView"
/>
<TextView
android:id="@+id/contact"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/name"
android:text="TextView"
android:layout_alignBaseline="@+id/address"
android:layout_alignBottom="@+id/address"
android:layout_toRightOf="@+id/address"
/>
<TextView
android:id="@+id/photo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/name"
android:text="TextView"
android:layout_alignBaseline="@+id/contact"
android:layout_alignBottom="@+id/contact"
android:layout_toRightOf="@+id/contact"
/>
</RelativeLayout>
fragment_myplaces xml layout
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent" android:layout_height="fill_parent"
android:orientation="vertical">
<TextView android:layout_width="fill_parent"
android:layout_height="wrap_content" android:padding="10dp"
android:text="Establishments in Panguil Laguna" android:textSize="20sp" />
<EditText android:id="@+id/myFilter" android:layout_width="match_parent"
android:layout_height="wrap_content" android:ems="10"
android:hint="Type here to search...">
<requestFocus />
</EditText>
<ListView android:id="@+id/listViewPlaces" android:layout_width="fill_parent"
android:layout_height="fill_parent" />
</LinearLayout>
DBAdapater类。我故意拼错它。
package com.hanapp.gps;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
import com.hanapp.gps.sqlite.DatabaseHelper;
public class DbAdapater {
public static final String KEY_ROWID = "_id";
public static final String KEY_ESTAB_NAME = "estab_name";
public static final String KEY_ESTAB_ADDRESS = "estab_address";
public static final String KEY_ESTAB_CONTACT = "estab_contact";
public static final String KEY_ESTAB_PHOTO = "estab_photo";
// public static final String KEY_ESTAB_DESC = "estab_desc";
// public static final String KEY_ESTAB_CATEGORY = "estab_category";
private static final String TAG = "DbAdapater";
private DatabaseHelper mDbHelper;
private SQLiteDatabase mDb;
private static final String DATABASE_NAME = "Panguil";
private static final String SQLITE_TABLE = "Establishments";
private static final int DATABASE_VERSION = 1;
private final Context mCtx;
private static final String DATABASE_CREATE =
"CREATE TABLE if not exists " + SQLITE_TABLE + " (" +
KEY_ROWID + " integer PRIMARY KEY autoincrement," +
KEY_ESTAB_NAME + "," +
KEY_ESTAB_ADDRESS + "," +
KEY_ESTAB_CONTACT + "," +
KEY_ESTAB_PHOTO + "," +
// KEY_ESTAB_DESC + "," +
// KEY_ESTAB_CATEGORY + "," +
" UNIQUE (" + KEY_ESTAB_NAME +"));";
private static class DatabaseHelper extends SQLiteOpenHelper {
DatabaseHelper(Context context){
super(context,DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
Log.w(TAG, DATABASE_CREATE);
db.execSQL(DATABASE_CREATE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
+ newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS " + SQLITE_TABLE);
onCreate(db);
}
}
public DbAdapater(Context context) {
this.mCtx = context;
}
public DbAdapater open() throws SQLException {
mDbHelper = new DatabaseHelper(mCtx);
mDb = mDbHelper.getWritableDatabase();
return this;
}
public void close() {
if (mDbHelper != null) {
mDbHelper.close();
}
}
//,String estab_contact, String estab_photo, String estab_desc,String estab_category
public long createEstablishments(String estab_name, String estab_address,String estab_contact, String estab_photo){
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_ESTAB_NAME, estab_name);
initialValues.put(KEY_ESTAB_ADDRESS, estab_address);
initialValues.put(KEY_ESTAB_CONTACT, estab_contact);
initialValues.put(KEY_ESTAB_PHOTO, estab_photo);
// initialValues.put(KEY_ESTAB_DESC, estab_desc);
// initialValues.put(KEY_ESTAB_CATEGORY, estab_category);
return mDb.insert(SQLITE_TABLE, null, initialValues);
}
public boolean deleteAllEstablishments() {
int doneDelete = 0;
doneDelete = mDb.delete(SQLITE_TABLE, null , null);
Log.w(TAG, Integer.toString(doneDelete));
return doneDelete > 0;
}
public Cursor fetchEstablishmentsByName(String inputText) throws SQLException {
Log.w(TAG, inputText);
Cursor mCursor = null;
if (inputText == null || inputText.length () == 0) {
mCursor = mDb.query( SQLITE_TABLE, new String[] {KEY_ROWID,
KEY_ESTAB_NAME, KEY_ESTAB_ADDRESS, KEY_ESTAB_CONTACT, KEY_ESTAB_PHOTO,},
null, null, null, null, null);
//, KEY_ESTAB_CONTACT, KEY_ESTAB_PHOTO, KEY_ESTAB_DESC, KEY_ESTAB_CATEGORY
}
else {
mCursor = mDb.query(SQLITE_TABLE, new String[] {KEY_ROWID,
KEY_ESTAB_NAME, KEY_ESTAB_ADDRESS, KEY_ESTAB_CONTACT, KEY_ESTAB_PHOTO,},
KEY_ESTAB_NAME + " like '%" + inputText + "%'", null,
null, null, null,null);
}
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
//, KEY_ESTAB_CONTACT, KEY_ESTAB_PHOTO, KEY_ESTAB_DESC, KEY_ESTAB_CATEGORY
}
public Cursor fetchAllEstablishments() {
Cursor mCursor = mDb.query(SQLITE_TABLE, new String[] {KEY_ROWID,
KEY_ESTAB_NAME, KEY_ESTAB_ADDRESS, KEY_ESTAB_CONTACT, KEY_ESTAB_PHOTO,},
null, null, null, null, null);
//, KEY_ESTAB_CONTACT, KEY_ESTAB_PHOTO, KEY_ESTAB_DESC, KEY_ESTAB_CATEGORY
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
public void insertSomeEstablishments() {
//,"09264346557","Not Available","River Tubing/Trekking/Rafting/Camping/Hanging Bridge" +
// "Swimming/Biyak na Bato/Pavilion","Tourist"
//ECO PARK
createEstablishments("Panguil River Eco Park","Natividad Extension, Brgy. Natividad, Pangil, Luzon 4018, Philippines","09264346557","Not Available");
}
}
MyPlaces。片段
package com.hanapp.gps;
import java.util.ArrayList;
import java.util.List;
import com.hanapp.gps.R;
import android.app.Fragment;
import android.content.Context;
import android.database.Cursor;
import android.os.Bundle;
import android.support.v4.widget.SimpleCursorAdapter;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.FilterQueryProvider;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.Toast;
import com.hanapp.gps.adapter.*;
public class MyPlaces extends Fragment {
private DbAdapater dbHelper;
private SimpleCursorAdapter dataAdapter;
public MyPlaces(){}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_myplaces, container, false);
dbHelper = new DbAdapater(getActivity());
dbHelper.open();
//Clean all data
dbHelper.deleteAllEstablishments();
//Add some data
dbHelper.insertSomeEstablishments();
//Generate ListView from SQLite Database
displayListView(rootView);
return rootView;
// return rootView;
}
public void displayListView(View v) {
Cursor cursor = dbHelper.fetchAllEstablishments();
// The desired columns to be bound
String[] columns = new String[] {
DbAdapater.KEY_ESTAB_NAME,
DbAdapater.KEY_ESTAB_ADDRESS,
DbAdapater.KEY_ESTAB_CONTACT,
DbAdapater.KEY_ESTAB_PHOTO
// DbAdapater.KEY_ESTAB_DESC,
// DbAdapater.KEY_ESTAB_CATEGORY
//CountriesDbAdapter.KEY_IMAGE
};
// the XML defined views which the data will be bound to
int[] to = new int[] {
R.id.name,
R.id.address,
R.id.contact,
R.id.photo
};
// create the adapter using the cursor pointing to the desired data
//as well as the layout information
//mCurAdapter = new SimpleCursorAdapter(view.getContext(),android.R.layout.simple_list_item_1,mNotesCursor,from,to,0);
dataAdapter = new SimpleCursorAdapter(v.getContext(), android.R.layout.simple_expandable_list_item_1, cursor, columns, to,0);
// Assign adapter to ListView
ListView listView = (ListView) getActivity().findViewById(R.id.listViewPlaces);
listView.setAdapter(dataAdapter);
listView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> listView, View view,
int position, long id) {
// Get the cursor, positioned to the corresponding row in the result set
Cursor cursor = (Cursor) listView.getItemAtPosition(position);
// Get the state's capital from this row in the database.
String countryCode =
cursor.getString(cursor.getColumnIndexOrThrow("code"));
Toast.makeText(getActivity().getApplicationContext(),
countryCode, Toast.LENGTH_SHORT).show();
}
});
EditText myFilter = (EditText) getActivity().findViewById(R.id.myFilter);
myFilter.addTextChangedListener(new TextWatcher() {
public void afterTextChanged(Editable s) {
}
public void beforeTextChanged(CharSequence s, int start,
int count, int after) {
}
public void onTextChanged(CharSequence s, int start,
int before, int count) {
dataAdapter.getFilter().filter(s.toString());
}
});
dataAdapter.setFilterQueryProvider(new FilterQueryProvider() {
public Cursor runQuery(CharSequence constraint) {
return dbHelper.fetchEstablishmentsByName(constraint.toString());
}
});
}
}
//String[] values = new String[] { "Android", "iPhone", "WindowsMobile",
//"Blackberry", "WebOS", "Ubuntu", "Windows7", "Max OS X",
//"Linux", "OS/2" };
//ListView lv;
//lv = (ListView) rootView.findViewById(R.id.listView1);
//lv.setAdapter(new ArrayAdapter<String>(getActivity().getApplicationContext(),
//android.R.layout.simple_list_item_1 , values));
//
提前感谢您的评论和答案！
答案 0 :(得分：1)
ListView listView = (ListView) getActivity().findViewById(R.id.listViewPlaces); listView.setAdapter(dataAdapter);
您的列表视图尚未在活动层次结构中，并且无法在此处找到。在您传入的根视图上调用findViewById()作为displayListView()方法的参数：
ListView listView = (ListView)v.findViewById(R.id.listViewPlaces);