我将经度和经度值存储在SQLite数据库中，并且还有一个谷歌地图。我每次添加坐标时都试图在地图上显示自定义标记。我觉得我存储的价值并不遥远，我可以在地图上放置硬编码的自定义标记。我有一个for循环，它应循环遍历数据库中的每个条目。任何帮助将不胜感激。
DatabaseHelper.java
public class DatabaseHelper extends SQLiteOpenHelper {
SQLiteDatabase db;
private static final String DATABASE_NAME = "heartwise";
private static final int DATABASE_VERSION = 4;
private static final String TABLE_SERVICE = "service";
private static final String COLUMN_ID = "ID";
private static final String COLUMN_LOCATION = "location";
private static final String COLUMN_CONDITION = "condition";
private static final String COLUMN_DATE = "date";
private static final String COLUMN_TIME = "time";
private static final String COLUMN_LATITUDE = "latitude";
private static final String COLUMN_LONGITUDE = "longitude";
private static final String CREATE_SERVICE_TABLE = "create table if not
exists "
+ TABLE_SERVICE + "("
+ COLUMN_ID + " TEXT PRIMARY KEY,"
+ COLUMN_LOCATION + " TEXT,"
+ COLUMN_CONDITION + " TEXT,"
+ COLUMN_DATE + " TEXT,"
+ COLUMN_TIME + " TEXT,"
+ COLUMN_LATITUDE + " DECIMAL,"
+ COLUMN_LONGITUDE + " DECIMAL);";
Context context;
public DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
this.context = context;
}
@Override
public void onCreate(SQLiteDatabase db) {
this.db = db;
db.execSQL(CREATE_SERVICE_TABLE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
{
db.execSQL("DROP TABLE IF EXISTS " + TABLE_SERVICE);
// Create tables again
onCreate(db);
}
public void insertIntoServiceTable(Service service)
{
db = this.getWritableDatabase();
ContentValues values = new ContentValues();
String query = "SELECT * FROM service";
db.rawQuery(query, null);
values.put(COLUMN_ID, service.getID());
values.put(COLUMN_LOCATION, service.getLocation());
values.put(COLUMN_CONDITION, service.getCondition());
values.put(COLUMN_DATE, service.getDate());
values.put(COLUMN_TIME, service.getTime());
values.put(COLUMN_LATITUDE, service.getLatitude());
values.put(COLUMN_LONGITUDE, service.getLongitude());
db.insert(TABLE_SERVICE, null, values);
db.close();
}
public List<Service> getDataFromServiceTable()
{
List<Service> serviceList = new ArrayList<Service>();
String query = "select * from "+ TABLE_SERVICE;
db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(query,null);
if (cursor.moveToFirst()){
do {
Service service = new Service();
service.setID(cursor.getString(0));
service.setLocation(cursor.getString(1));
service.setCondition(cursor.getString(2));
service.setDate(cursor.getString(3));
service.setTime(cursor.getString(4));
service.setLatitude(cursor.getString(5));
service.setLongitude(cursor.getString(6));
serviceList.add(service);
}while (cursor.moveToNext());
}
return serviceList;
}
public void updateServiceData(Service service)
{
db = this.getWritableDatabase();
ContentValues values = new ContentValues();
String query = "SELECT * FROM service";
db.rawQuery(query, null);
values.put(COLUMN_ID, service.getID());
values.put(COLUMN_LOCATION, service.getLocation());
values.put(COLUMN_CONDITION, service.getCondition());
values.put(COLUMN_DATE, service.getDate());
values.put(COLUMN_TIME, service.getTime());
values.put(COLUMN_LATITUDE, service.getLatitude());
values.put(COLUMN_LONGITUDE, service.getLongitude());
db.update(TABLE_SERVICE, values, COLUMN_ID + "=?", new String[]
{String.valueOf(service.getID())});
}
public void deleteItem(String id){
db = this.getWritableDatabase();
db.delete(TABLE_SERVICE,COLUMN_ID + "=?",new String[]
{String.valueOf(id)});
db.close();
}
}
AddScreen.java
public class AddScreen extends AppCompatActivity
{
EditText editTextID, editTextLocation, editTextDate, editTextTime,
editTextLatitude, editTextLongitude;
RadioGroup radioGroup;
Button buttonSubmit;
DatabaseHelper helper; //instance of DatabaseHelper class
List<Service> serviceList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.add_screen);
serviceList = new ArrayList<Service>(); //
editTextID = (EditText) findViewById(R.id.idET);
editTextLocation = (EditText) findViewById(R.id.locationET);
radioGroup =(RadioGroup)findViewById(R.id.radio_group);
editTextDate = (EditText) findViewById(R.id.dateET);
editTextTime = (EditText) findViewById(R.id.timeET);
editTextLatitude = (EditText) findViewById(R.id.latitudeET);
editTextLongitude = (EditText) findViewById(R.id.longitudeET);
buttonSubmit = (Button) findViewById(R.id.submitButton);
buttonSubmit.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v)
{
String id = editTextID.getText().toString();
String location = editTextLocation.getText().toString();
String radioValue =((RadioButton)findViewById(radioGroup.
getCheckedRadioButtonId())).getText().toString();
String date = editTextDate.getText().toString();
String time = editTextTime.getText().toString();
String latitude = editTextLatitude.getText().toString();
String longitude = editTextLongitude.getText().toString();
if(id.length() == 0)
{
editTextID.requestFocus();
editTextID.setError("Please enter the AED ID");
}
else if(id.length() > 5)
{
editTextID.requestFocus();
editTextID.setError("The ID must be less than 6
characters");
}
else if(location.length() == 0)
{
editTextLocation.requestFocus();
editTextLocation.setError("Please enter the AED location");
}
else if(date.length() == 0)
{
editTextDate.requestFocus();
editTextDate.setError("Please enter the date");
}
else if(time.length() == 0)
{
editTextTime.requestFocus();
editTextTime.setError("Please enter the time");
}
else if(latitude.length() == 0)
{
editTextLatitude.requestFocus();
editTextLatitude.setError("Please enter location latitude");
}
else if(longitude.length() == 0)
{
editTextLongitude.requestFocus();
editTextLongitude.setError("Please enter location
longitude");
}
else
{
Service service = new Service();
service.setID(id);
service.setLocation(location);
service.setCondition(radioValue);
service.setDate(date);
service.setTime(time);
service.setLatitude(latitude);
service.setLongitude(longitude);
helper = new DatabaseHelper(AddScreen.this);
helper.insertIntoServiceTable(service);
}
editTextID.setText("");
editTextLocation.setText("");
editTextDate.setText("");
editTextTime.setText("");
editTextLatitude.setText("");
editTextLongitude.setText("");
Toast.makeText(AddScreen.this, "You have added service details
successfully!", Toast.LENGTH_LONG);
}
});
}
SearchScreen.xml（地图）
public class SearchScreen extends FragmentActivity implements
OnMapReadyCallback, GoogleMap.OnMarkerClickListener {
private GoogleMap googleMap;
public static final List<LatLng> locations = new ArrayList<>();
EditText editTextLongitude;
EditText editTextLatitude;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.search_screen);
SupportMapFragment mapFragment = (SupportMapFragment)
getSupportFragmentManager().findFragmentById(map);
mapFragment.getMapAsync(this);;
editTextLatitude = (EditText)findViewById(R.id.latitudeET);
editTextLongitude = (EditText)findViewById(R.id.longitudeET);
}
@Override
public void onMapReady(GoogleMap googleMap) {
this.googleMap = googleMap;
this.googleMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
for (LatLng location: locations){
this.googleMap.addMarker(new MarkerOptions()
.position(location)
.title("bla bla bla")
.snippet("Contact No: 051 27385")
.icon(BitmapDescriptorFactory.fromResource
(R.drawable.heartmarker)));
}
this.googleMap.setOnMarkerClickListener(this);
}
public void onMapSearch(View view)
{
EditText locationSearch = (EditText)
findViewById(R.id.editTextSearch);
String location = locationSearch.getText().toString();
List<Address> addressList = null;
if (location != null || !location.equals("")) {
Geocoder geocoder = new Geocoder(this);
try {
addressList = geocoder.getFromLocationName(location, 1);
} catch (IOException e) {
e.printStackTrace();
}
Address address = addressList.get(0);
LatLng latLng = new LatLng(address.getLatitude(),
address.getLongitude());
googleMap.addMarker(new
MarkerOptions().position(latLng).title("Marker"));
googleMap.animateCamera(CameraUpdateFactory.newLatLng(latLng));
}
}