SQlite & 在 Google 地图上添加乘法标记
SQlite & add a multiply markers on Google Map
我想要在地图上绘制自定义标记。如何组织多个标记的显示。
public class DatabaseHelper extends SQLiteOpenHelper {
static final String TABLE = "geotable";
public DatabaseHelper(Context context) {
super(context, "myDB", null, 1);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("create table geotable ("
+ "id integer primary key autoincrement,"
+ "image text,"
+ "lng text,"
+ "lat text" + ");");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS "+TABLE);
onCreate(db);
}
首先 class 我在数据库中创建 table。然后把信息放在这个 table
case R.id.saveToBD:
cv.put("image", tex);
cv.put("lng", lng);
cv.put("lat", ltd);
break;
然后我需要显示从数据库到地图的所有标记。但我在地图上只看到一个(最后一个)标记。我如何安排一个周期?
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {
DatabaseHelper sqlHelper;
SQLiteDatabase db;
Cursor userCursor;
private GoogleMap googleMap;
private String imageTest;
double lngTest, ltdTest;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
sqlHelper = new DatabaseHelper(getApplicationContext());
}
@Override
public void onResume() {
super.onResume();
db = sqlHelper.getReadableDatabase();
userCursor = db.query("geotable", null, null, null, null, null, null);
if (userCursor.moveToFirst()) {
int imageColIndex = userCursor.getColumnIndex("image");
int lngColIndex = userCursor.getColumnIndex("lng");
int latlColIndex = userCursor.getColumnIndex("lat");
do {
imageTest = userCursor.getString(imageColIndex);
lngTest = userCursor.getDouble(lngColIndex);
ltdTest = userCursor.getDouble(latlColIndex);
}
while (userCursor.moveToNext());
}
else
userCursor.close();
}
@Override
public void onDestroy() {
super.onDestroy();
db.close();
userCursor.close();
}
@Override
public void onMapReady(GoogleMap googleMap) {
googleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(
new LatLng(ltdTest, lngTest), 16));
// You can customize the marker image using images bundled with
// your app, or dynamically generated bitmaps.
googleMap.addMarker(new MarkerOptions()
.icon(BitmapDescriptorFactory.fromPath(imageTest))
.anchor(0.0f, 1.0f) // Anchors the marker on the bottom left
.position(new LatLng(ltdTest, lngTest)));
}
添加 ArrayList,
if (userCursor.moveToFirst()) {
int imageColIndex = userCursor.getColumnIndex("image");
int lngColIndex = userCursor.getColumnIndex("lng");
int latlColIndex = userCursor.getColumnIndex("lat");
do {
imageTest = userCursor.getString(imageColIndex);
lngTest = userCursor.getDouble(lngColIndex);
ltdTest = userCursor.getDouble(latlColIndex);
geoList.add(imageTest);
geoList.add(lngTest);
geoList.add(ltdTest);
}
while (userCursor.moveToNext());
}
然后循环显示标记
for (int i = 0; i < geoList.size(); i=i+3) {
googleMap.addMarker(new MarkerOptions()
.icon(BitmapDescriptorFactory.fromPath((String) geoList.get(i)))
.anchor(0.0f, 1.0f) // Anchors the marker on the bottom left
.position(new LatLng((Double) geoList.get(i+2), (Double) geoList.get(i+1))));
}
地图上只显示最后添加到数据库的标记,我添加了 2-10 个标记,但只看到最后一个。
您正在 onResume()
中的整数变量中从 geotable
获取数据:
imageTest = userCursor.getString(imageColIndex);
lngTest = userCursor.getDouble(lngColIndex);
ltdTest = userCursor.getDouble(latlColIndex);
然后在 onMapReady(GoogleMap googleMap)
中,您使用上述变量的值添加标记,其中仅包含 geotable
:
的最后一行数据
googleMap.addMarker(new MarkerOptions()
.icon(BitmapDescriptorFactory.fromPath(imageTest))
.anchor(0.0f, 1.0f) // Anchors the marker on the bottom left
.position(new LatLng(ltdTest, lngTest)));
您应该使用 ArrayList 从 geotable
获取数据并在 onMapReady(GoogleMap googleMap)
的循环内添加多个标记。
我想要在地图上绘制自定义标记。如何组织多个标记的显示。
public class DatabaseHelper extends SQLiteOpenHelper {
static final String TABLE = "geotable";
public DatabaseHelper(Context context) {
super(context, "myDB", null, 1);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("create table geotable ("
+ "id integer primary key autoincrement,"
+ "image text,"
+ "lng text,"
+ "lat text" + ");");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS "+TABLE);
onCreate(db);
}
首先 class 我在数据库中创建 table。然后把信息放在这个 table
case R.id.saveToBD:
cv.put("image", tex);
cv.put("lng", lng);
cv.put("lat", ltd);
break;
然后我需要显示从数据库到地图的所有标记。但我在地图上只看到一个(最后一个)标记。我如何安排一个周期?
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {
DatabaseHelper sqlHelper;
SQLiteDatabase db;
Cursor userCursor;
private GoogleMap googleMap;
private String imageTest;
double lngTest, ltdTest;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
sqlHelper = new DatabaseHelper(getApplicationContext());
}
@Override
public void onResume() {
super.onResume();
db = sqlHelper.getReadableDatabase();
userCursor = db.query("geotable", null, null, null, null, null, null);
if (userCursor.moveToFirst()) {
int imageColIndex = userCursor.getColumnIndex("image");
int lngColIndex = userCursor.getColumnIndex("lng");
int latlColIndex = userCursor.getColumnIndex("lat");
do {
imageTest = userCursor.getString(imageColIndex);
lngTest = userCursor.getDouble(lngColIndex);
ltdTest = userCursor.getDouble(latlColIndex);
}
while (userCursor.moveToNext());
}
else
userCursor.close();
}
@Override
public void onDestroy() {
super.onDestroy();
db.close();
userCursor.close();
}
@Override
public void onMapReady(GoogleMap googleMap) {
googleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(
new LatLng(ltdTest, lngTest), 16));
// You can customize the marker image using images bundled with
// your app, or dynamically generated bitmaps.
googleMap.addMarker(new MarkerOptions()
.icon(BitmapDescriptorFactory.fromPath(imageTest))
.anchor(0.0f, 1.0f) // Anchors the marker on the bottom left
.position(new LatLng(ltdTest, lngTest)));
}
添加 ArrayList,
if (userCursor.moveToFirst()) {
int imageColIndex = userCursor.getColumnIndex("image");
int lngColIndex = userCursor.getColumnIndex("lng");
int latlColIndex = userCursor.getColumnIndex("lat");
do {
imageTest = userCursor.getString(imageColIndex);
lngTest = userCursor.getDouble(lngColIndex);
ltdTest = userCursor.getDouble(latlColIndex);
geoList.add(imageTest);
geoList.add(lngTest);
geoList.add(ltdTest);
}
while (userCursor.moveToNext());
}
然后循环显示标记
for (int i = 0; i < geoList.size(); i=i+3) {
googleMap.addMarker(new MarkerOptions()
.icon(BitmapDescriptorFactory.fromPath((String) geoList.get(i)))
.anchor(0.0f, 1.0f) // Anchors the marker on the bottom left
.position(new LatLng((Double) geoList.get(i+2), (Double) geoList.get(i+1))));
}
地图上只显示最后添加到数据库的标记,我添加了 2-10 个标记,但只看到最后一个。
您正在 onResume()
中的整数变量中从 geotable
获取数据:
imageTest = userCursor.getString(imageColIndex);
lngTest = userCursor.getDouble(lngColIndex);
ltdTest = userCursor.getDouble(latlColIndex);
然后在 onMapReady(GoogleMap googleMap)
中,您使用上述变量的值添加标记,其中仅包含 geotable
:
googleMap.addMarker(new MarkerOptions()
.icon(BitmapDescriptorFactory.fromPath(imageTest))
.anchor(0.0f, 1.0f) // Anchors the marker on the bottom left
.position(new LatLng(ltdTest, lngTest)));
您应该使用 ArrayList 从 geotable
获取数据并在 onMapReady(GoogleMap googleMap)
的循环内添加多个标记。