我尝试调整Google记事本教程（http://developer.android.com/resources/tutorials/notepad/index.html），以便在用户标记当前位置时使用SQLite数据库存储GPS合作。我已经毫无困难地将位置添加到数据库中，但目前无法从数据库填充数组以便在地图上绘制位置
private void fillData() {
/**
* Get all of the geotags from the database and populate the strarrlatitude and strarrlongitude arrays
* Also calls 'drawpins' to draw the geotags on the map
*/
Cursor c = mDbHelper.fetchAllNotes();
startManagingCursor(c);
strarrlatitude = new String[] { LocationsDbAdapter.COL_LATITUDE};
System.out.println(strarrlatitude);
strarrlongitude = new String[] { LocationsDbAdapter.COL_LONGITUDE };
drawpins();
}
我正在使用一个名为LocationsDbAdapter的单独类来处理数据库管理，如记事本教程中所示。 COL_LATITUDE和COL_LONGITUDE变量指向列标题。
我使用for循环来确定似乎没有任何东西进入strarrlatitude数组但是使用SQLite CLI我检查了数据库是否正在确定
非常感谢任何帮助 - 如果需要更多信息，我会尽快上传
非常感谢
编辑：添加了以下两个主要类别以供额外参考。我试图不要过多地提供过多的信息，但那是判断错误。
package com.nick.locationapp;
import java.util.List;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.drawable.Drawable;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.text.AlteredCharSequence;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapView;
import com.google.android.maps.MyLocationOverlay;
import com.google.android.maps.Overlay;
import com.google.android.maps.OverlayItem;
import com.nick.androidsoar.R;
public class AndroidSoarActivity extends MapActivity {
/** Called when the activity is first created. */
LinearLayout linearLayout;
MapView mapView;
TextView LocationText;
double dbllatitude;
double dbllongitude;
double dblaltitude;
String debugstring;
String strlatitude = "0";
String strlongitude = "0";
String[] strarrlatitude;
String[] strarrlongitude;
String[] strarrlatitude1 = {"50.0","40.0","43.0","100.0"};
String[] strarrlongitude1 = {"12.4","123.4","60.2","72.0"};
Double[] debuglat = {50.0,40.0,43.0,100.0};
Double[] debuglong = {12.4,123.4,60.2,72.0};
Double dbllat;
Double dbllong;
int intlatitude;
int intlongitude;
private LocationsDbAdapter mDbHelper;
public static final int INSERT_ID = Menu.FIRST;
List<Overlay> mapOverlays;
Drawable drawable;
HelloItemizedOverlay itemizedOverlay;
@Override
protected boolean isRouteDisplayed() {
return false;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//Identifies the textview as variable 'LocationText'
LocationText = (TextView)findViewById(R.id.locationtext);
//mDbHelper points to the LocationsDbAdapter class used for handling the database
mDbHelper = new LocationsDbAdapter (this);
mDbHelper.open();
//defines the mapview as variable 'mapView' and enables zoom controls
mapView = (MapView) findViewById(R.id.mapview);
mapView.setBuiltInZoomControls(true);
mapOverlays = mapView.getOverlays();
//points variable 'drawable' to the icon resource of a pushpin, used for marking tags on the map
drawable = this.getResources().getDrawable(R.drawable.pushpin);
//Adds a current location overlay to the map 'mapView' and turns on the map's compass
MyLocationOverlay myLocationOverlay = new MyLocationOverlay(this, mapView);
mapView.getOverlays().add(myLocationOverlay);
myLocationOverlay.enableMyLocation();
myLocationOverlay.enableCompass();
mapView.postInvalidate();
/**
* Code required to receive gps location. Activates GPS provider, and is set to update only after
* at least 10 seconds and a position change of at least 10 metres
*/
LocationListener locationListener = new MyLocationListener();
//setting up the location manager
LocationManager locman = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
locman.requestLocationUpdates(LocationManager.GPS_PROVIDER, 10000, 10, locationListener);
//fillData();
}
/**
* Generates the menu from the resource 'mainmenu.xml'
*/
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.mainmenu, menu);
return true;
}
/**
* Code to run depending on the menu button pressed
*/
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.new_tag:
createTag();
fillData();
//Toast.makeText(getApplicationContext(), "geotag added to db", Toast.LENGTH_SHORT).show();
return true;
case R.id.draw_pins:
//fillData();
drawpins();
return true;
case R.id.create_tag:
Intent intent = new Intent(AndroidSoarActivity.this, TagCreate.class);
startActivity(intent);
}
return super.onOptionsItemSelected(item);
}
/**
* Create a new geotag pin from the current location
*/
private void createTag() {
//String titleName = "title " + titleNumber++;
mDbHelper.createNote(strlatitude, strlongitude);
Toast.makeText(getApplicationContext(), "geotag of lat: "+dbllatitude+" long: "+dbllongitude+" added to db ", Toast.LENGTH_SHORT).show();
fillData();
}
private void fillData() {
/**
* Get all of the geotags from the database and populate the strarrlatitude and strarrlongitude arrays
* Also calls 'drawpins' to draw the geotags on the map
*/
System.out.println("Fetching data");
Cursor c = mDbHelper.fetchAllNotes();
System.out.println(c.toString());
startManagingCursor(c);
strarrlatitude = new String[] { LocationsDbAdapter.COL_LATITUDE };
//System.out.println(strarrlatitude);
strarrlongitude = new String[] { LocationsDbAdapter.COL_LONGITUDE };
}
/**
* Creates an array of geopoints, pulling the locations from strarrlatitude and strarrlongitude
* and creates a mapview overlay using the geopoints
*/
private void drawpins() {
itemizedOverlay = new HelloItemizedOverlay(drawable);
GeoPoint[] mapPoints = new GeoPoint[strarrlatitude.length];
OverlayItem[] mapItems = new OverlayItem[strarrlatitude.length];
for(int i=1; i<strarrlatitude.length;i++){
dbllat = Double.parseDouble(strarrlatitude[i]);
dbllong = Double.parseDouble(strarrlongitude[i]);
System.out.println(i);
mapPoints[i] = new GeoPoint((int) (dbllat * 1E6), (int) (dbllong * 1E6));
mapItems[i] = new OverlayItem(mapPoints[i], "", "");
itemizedOverlay.addOverlay(mapItems[i]);
mapOverlays.add(itemizedOverlay);
}
}
private final class MyLocationListener implements LocationListener {
/**
* Code to run when the listener receives a new location
*/
@Override
public void onLocationChanged(Location locFromGps) {
Toast.makeText(getApplicationContext(), "Location changed, Lat: "+locFromGps.getLatitude()+" Long: "+ locFromGps.getLongitude(), Toast.LENGTH_SHORT).show();
//LocationText.setText("Your Location: Latitude " +locFromGps.getLatitude() + " Longitude: " +locFromGps.getLongitude());
dbllatitude = locFromGps.getLatitude();
dbllongitude = locFromGps.getLongitude();
dblaltitude = locFromGps.getAltitude();
strlatitude = Double.toString(dbllatitude);
strlongitude = Double.toString(dbllongitude);
dblaltitude = (dblaltitude / 0.3048);
LocationText.setText("Your Location: Latitude " + dbllatitude + " Longitude: " +dbllongitude + " Altitude " + dblaltitude);
}
@Override
public void onProviderDisabled(String provider) {
// called when the GPS provider is turned off (user turning off the GPS on the phone)
}
@Override
public void onProviderEnabled(String provider) {
// called when the GPS provider is turned on (user turning on the GPS on the phone)
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// called when the status of the GPS provider changes
}
}
}
/ ** *以下课程改编自Google的Android记事本教程：http://developer.android.com/resources/tutorials/notepad/index.html * * /
package com.nick.locationapp;
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 LocationsDbAdapter {
public static final String COL_LATITUDE = "latitude";
public static final String COL_LONGITUDE = "longitude";
//public static final String KEY_NOTE = "note";
public static final String COL_TITLE = "title";
public static final String COL_ROWID = "_id";
//public static final String TABLE_LOC = "locations";
private static final String TAG = "LocationsDbAdapter";
private DatabaseHelper mDbHelper;
private SQLiteDatabase mDb;
/**
* Database creation sql statement
*/
private static final String DATABASE_CREATE =
"CREATE TABLE locations (_id integer primary key autoincrement, "
+ "latitude text not null, longitude text not null);";
private static final String DATABASE_NAME = "data";
private static final String DATABASE_TABLE = "locations";
private static final int DATABASE_VERSION = 1;
private final Context mCtx;
private static class DatabaseHelper extends SQLiteOpenHelper {
DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
/**
* SQL for creating the table. Table and column names are declared as variables
*/
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE "+DATABASE_TABLE+" ("+COL_ROWID+ " INTEGER PRIMARY KEY AUTOINCREMENT, "+COL_LATITUDE+ " TEXT, "+COL_LONGITUDE+" TEXT "+COL_TITLE+" TEXT)");
}
@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 location");
onCreate(db);
}
}
public LocationsDbAdapter(Context ctx) {
this.mCtx = ctx;
}
public LocationsDbAdapter open() throws SQLException {
mDbHelper = new DatabaseHelper(mCtx);
mDb = mDbHelper.getWritableDatabase();
return this;
}
public void close() {
mDbHelper.close();
}
/**
* Code for adding latitude and longitude into the database
* @param latitude
* @param longitude
* @return
*/
public long createNote(String latitude, String longitude) {
ContentValues geotagValues = new ContentValues();
geotagValues.put(COL_LATITUDE, latitude);
geotagValues.put(COL_LONGITUDE, longitude);
//geotagValues.put(COL_TITLE, title);
return mDb.insert(DATABASE_TABLE, null, geotagValues);
}
/**
* Query to return all data
* @return
*/
public Cursor fetchAllNotes() {
return mDb.query(DATABASE_TABLE, new String[] {COL_ROWID, COL_LATITUDE, COL_LONGITUDE}, null, null, null, null, null);
}
}
答案 0 :(得分：1)
*
public void getData()
{
List<String> labels = new ArrayList<String>();
placeData = new PlaceDataSQL(MainActivity.this);
String selectQuery = "SELECT * FROM xmlTable;";
SQLiteDatabase db = placeData.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
{
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
labels.add(cursor.getString(1));
Log.i("imagespath",arr[i]);
i++;
} while (cursor.moveToNext());
}
cursor.close();enter code here
db.close();
}
}
*