有人可以告诉我如何在ListActivity选项卡中轻松显示sqllite中的每条记录？我有点困惑。我是否必须在TabActivity或ListActivity中的helper类中创建db或两者？我的db helper类如下：
package tabs.app;
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;
public class DBAdapter
{
private static String DB_PATH = "/data/data/tabs.app/databases/";
public static final String KEY_ROWID = "_id";
public static final String KEY_LATITUDE = "latitude";
public static final String KEY_LONGITUDE = "longitude";
private static final String TAG = "DBAdapter";
private static final String DATABASE_NAME = "coords";
private static final String DATABASE_TABLE = "coordsStorages";
private static final int DATABASE_VERSION = 2;
/* private static final String DATABASE_CREATE =
"create table coordsStorage (_id integer primary key autoincrement, latitude integer not null, longitude integer not null)";
*/
public Context context;
private DatabaseHelper DBHelper;
private SQLiteDatabase db;
public DBAdapter(Context ctx)
{
this.context = ctx;
DBHelper = new DatabaseHelper(context);
}
private static class DatabaseHelper extends SQLiteOpenHelper
{
DatabaseHelper(Context context)
{
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db)
{
db.execSQL("create table coordsStorages (_id integer primary key autoincrement, latitude integer not null, longitude integer not null)");
}
@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 titles");
onCreate(db);
}
}
//---opens the database---
public DBAdapter open() throws SQLException
{
db = DBHelper.getWritableDatabase();
return this;
}
//---closes the database---
public void close()
{
DBHelper.close();
}
//---insert a title into the database---
public long insertCoords(int latitude, int longitude)
{
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_LATITUDE, latitude);
initialValues.put(KEY_LONGITUDE, longitude);
return db.insert(DATABASE_TABLE, null, initialValues);
}
public void openDataBase() throws SQLException{
//Open the database
String myPath = DB_PATH + DATABASE_NAME;
db = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
}
//---deletes a particular title---
public boolean deleteTitle(long rowId)
{
return db.delete(DATABASE_TABLE, KEY_ROWID +
"=" + rowId, null) > 0;
}
//---retrieves all the titles---
public Cursor getAllTitles()
{
return db.query(DATABASE_TABLE, new String[] {
KEY_ROWID,
KEY_LATITUDE,
KEY_LONGITUDE},
null,
null,
null,
null,
null);
}
//---retrieves a particular title---
public Cursor getTitle(long rowId) throws SQLException
{
Cursor mCursor =
db.query(true, DATABASE_TABLE, new String[] {
KEY_ROWID,
KEY_LATITUDE,
KEY_LONGITUDE},
KEY_ROWID + "=" + rowId,
null,
null,
null,
null,
null);
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
//---updates a title---
/*public boolean updateTitle(long rowId, int latitude,
int longitude)
{
ContentValues args = new ContentValues();
args.put(KEY_LATITUDE, latitude);
args.put(KEY_LONGITUDE, longitude);
return db.update(DATABASE_TABLE, args,
KEY_ROWID + "=" + rowId, null) > 0;
}*/
}
And Im trying to retrieve the records in TabActivity like this:
public class Areas extends ListActivity {
DBAdapter db;
SimpleCursorAdapter mAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.areas_layout);
db = new DBAdapter(this);
db.open();
Cursor c = db.getAllTitles();
startManagingCursor(c);
String[] display = new String[] { db.KEY_LATITUDE };
int[] to = new int[] { R.id.row_latitude};
/*
String[] display2 = new String[] { db.KEY_LONGITUDE };
int[] to2 = new int[] { R.id.row_longitude};*/
mAdapter = new SimpleCursorAdapter(this, R.layout.areas_layout, c, display, to);
setListAdapter(mAdapter);
/* mAdapter2 = new SimpleCursorAdapter(this, R.layout.areas_layout, c, display2, to2);
setListAdapter(mAdapter2);*/
db.close();
}
/*
private void fillData() {
// Get all of the rows from the database and create the item list
Cursor c = db.getAllTitles();
startManagingCursor(c);
}*/
}
每当我尝试这样做时，错误日志都会输出：
06-07 09:51:56.529:
ERROR/AndroidRuntime(2034): Uncaught
handler: thread main exiting due to
uncaught exception
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034):
java.lang.RuntimeException: Unable to
start activity
ComponentInfo{tabs.app/tabs.app.Areas}:
java.lang.RuntimeException: Your
content must have a ListView whose id
attribute is 'android.R.id.list'
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2401)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.app.ActivityThread.startActivityNow(ActivityThread.java:2242)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.app.LocalActivityManager.moveToState(LocalActivityManager.java:127)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.app.LocalActivityManager.startActivity(LocalActivityManager.java:339)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:631)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.widget.TabHost.setCurrentTab(TabHost.java:317)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.widget.TabHost$2.onTabSelectionChanged(TabHost.java:127)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.widget.TabWidget$TabClickListener.onClick(TabWidget.java:346)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.view.View.performClick(View.java:2344)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.view.View.onTouchEvent(View.java:4133)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.view.View.dispatchTouchEvent(View.java:3672)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:850)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent( oneWindow.java:1712)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1202)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.app.Activity.dispatchTouchEvent(Activity.java:1987)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent( oneWindow.java:1696)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.view.ViewRoot.handleMessage(ViewRoot.java:1658)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.os.Handler.dispatchMessage(Handler.java:99)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.os.Looper.loop(Looper.java:123)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.app.ActivityThread.main(ActivityThread.java:4203)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
java.lang.reflect.Method.invokeNative(Native
Method)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
java.lang.reflect.Method.invoke(Method.java:521)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
com.android.internal.os.ZygoteInit.main(ZygoteInit.java:549)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
dalvik.system.NativeStart.main(Native
Method)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): Caused by:
java.lang.RuntimeException: Your
content must have a ListView whose id
attribute is 'android.R.id.list'
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.app.ListActivity.onContentChanged(ListActivity.java:236)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:316)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.app.Activity.setContentView(Activity.java:1620)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
tabs.app.Areas.onCreate(Areas.java:18)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1123)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): at
android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2364)
06-07 09:51:56.559:
ERROR/AndroidRuntime(2034): ... 30
more
06-07 09:51:56.619: INFO/Process(51):
Sending signal. PID: 2034 SIG: 3
06-07 09:51:56.619:
INFO/dalvikvm(2034): threadid=7:
reacting to signal 3
06-07 09:51:56.619:
ERROR/dalvikvm(2034): Unable to open
stack trace file
'/data/anr/traces.txt': Permission
denied
有人可以告诉我我做错了什么吗？非常感谢！
答案 0 :(得分：1)
java.lang.RuntimeException: Your
content must have a ListView whose id
attribute is 'android.R.id.list'
此错误表示您的视图文件（R.layout.areas_layout）中的ListView未被赋予正确的ID。您的ListView XML必须如下所示：
<ListView
android:id="@android:id/list"…
尝试这样做，看看它是否解决了您的问题：
****************编辑****************************** ********
感谢您分享您的布局代码，问题似乎是您的列表行xml布局与主内容视图位于同一布局文件中。你需要让他们分开。
在您的R.layout.areas_layout文件中，只需要您的linearlayout，然后您的列表视图就会为您的行创建一个单独的xml文件，如下所示：
<?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="wrap_content"
>
<TextView
android:id="@+id/row_latitude"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
/>
</LinearLayout>
然后，您将列表行传递给SimpleCursorAdapter：
mAdapter = new SimpleCursorAdapter(this, R.layout.my_list_row, c, display, to);
答案 1 :(得分：1)
好的我已经解决了我添加了listview的问题，布局看起来像这样：
<TextView android:id="@+id/row_latitude" android:layout_width="wrap_content" android:layout_height="fill_parent" />
<ListView android:id="@android:id/list" android:layout_width="fill_parent" android:layout_height="wrap_content"></ListView>
所以基本上textView在listview之上。谢谢你的帮助伴侣！