Java SQlite&;在谷歌地图上添加多个标记
我想在地图上画一个自定义标记。如何组织多个标记的显示Java SQlite&;在谷歌地图上添加多个标记,java,android,sqlite,google-maps,cycle,Java,Android,Sqlite,Google Maps,Cycle,我想在地图上画一个自定义标记。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
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);
}
在第一个类中,我在db中创建表。然后把信息放在这个表中
case R.id.saveToBD:
cv.put("image", tex);
cv.put("lng", lng);
cv.put("lat", ltd);
break;
然后我需要一个显示所有标记从数据库到地图。但我在地图上只看到一个(最后一个)标记。我如何组织一个循环
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());
}
然后使用循环显示标记
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))));
}
for(int i=0;i
在地图上只显示最后添加到DB标记,我添加了2-10个标记,但只看到最后一个 您正在从
地理表中提取onResume()中整数变量的数据:
然后在onMapReady(GoogleMap-GoogleMap)
中,您使用上述变量的值添加标记,这些变量只包含地理表的最后一行数据:
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从地理表
中获取数据,并在onMapReady(GoogleMap GoogleMap)
中的循环中添加多个标记。请提供有关aloop坐标的更多信息。我没有更正将信息放入数据库,所有标记都设置为表,其中id=0;
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)));