谷歌地图通过wifi初始化位置

Question

I want to implement several things:

1. when the activity creates the google maps will show the estimated location based on wifi...
   how can I implement it?

2. I want to get the name of the location that user touch on google maps...
   I read that I can implement it with the method, however with this method I can only get the latitude and longitude on the place that the user touched:

    @Override public void onMapClick(LatLng point) { // TODO Auto-generated method stub } 

3. I want to enable the user to search place in google maps, is there any method to implement it?

This is my activity till now:

import java.lang.ref.WeakReference;

import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.GoogleMap.OnMarkerDragListener;
import com.google.android.gms.maps.MapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;

import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.v4.app.FragmentActivity;
import android.util.Log;
import android.view.View;
import android.view.ViewParent;
import android.widget.ImageView;
import android.widget.Toast;

public class itemSaleActivity extends FragmentActivity  {


    private static Context app;
    private static GoogleMap map;
    static final LatLng HAMBURG = new LatLng(53.558, 9.927);
    private static final int LOAD_COORD = 0;
    private ImageView pic;
    private LocationHandler mHandler;

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        // Set View to register.xml
        setContentView(R.layout.itemsale);

        app = getApplicationContext();
        Bundle extras = getIntent().getExtras();
        byte[] byteArray = extras.getByteArray("picture");
        Bitmap bmp = BitmapFactory.decodeByteArray(byteArray, 0, byteArray.length);

        pic = (ImageView) findViewById(R.id.itemImage);
        pic.setImageBitmap(bmp);

        map = ((MapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();
        //Marker hamburg = map.addMarker(new MarkerOptions().position(HAMBURG).title("Hamburg"));
        mHandler = new LocationHandler(this); 

        OnMarkerDragListener markerDragListener = new OnMarkerDragListener() {

            @Override
            public void onMarkerDragStart(Marker marker) {
                // Called when the marker drag is started

            }

            @Override
            public void onMarkerDragEnd(Marker marker) {
                // Called when the marker is dropped down.
                double[] coords = null;
                coords[0] = marker.getPosition().latitude;
                coords[1] = marker.getPosition().longitude;
                RestoreUIwithSavedLocation(coords);
                Toast.makeText(getApplicationContext(),"Pin Dropped at: " + coords[0] + ", " + coords[1]+marker.getTitle() , Toast.LENGTH_LONG).show();

            }

            @Override
            public void onMarkerDrag(Marker marker) {

            }
        };

        map.setOnMarkerDragListener(markerDragListener);

        View titleView = getWindow().findViewById(android.R.id.title);
        if (titleView != null) {
            ViewParent parent = titleView.getParent();
            if (parent != null && (parent instanceof View)) {
             View parentView = (View)parent;
             parentView.setVisibility(View.GONE);
            }
        }

     // You can also assign the title programmatically by passing a
     // CharSequence or resource id.
    }

    private void RestoreUIwithSavedLocation(double[] coordsArray) {
        Message.obtain(mHandler, LOAD_COORD, coordsArray).sendToTarget();
    }

    static class LocationHandler extends Handler {
        WeakReference<Activity> mActivity;

        public LocationHandler(Activity activity) {
            mActivity = new WeakReference<Activity>(activity);
        }

        public void handleMessage(Message msg) {
            Activity contextActivity = mActivity.get();
            switch ((int)msg.what) {

            case LOAD_COORD:
                map.clear();
                double[] coordArray = (double[])msg.obj;
                Marker marker = map.addMarker(new MarkerOptions().position(new LatLng(coordArray[0], coordArray[1])));
                map.moveCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(coordArray[0], coordArray[1]), 18));
                map.animateCamera(CameraUpdateFactory.zoomTo(18), 2000, null);
                marker.setDraggable(true);
                String s = Double.toString(coordArray[0]) + ", " + Double.toString(coordArray[1]);              
                Toast.makeText(app,"in the case"+s , Toast.LENGTH_LONG).show();
                break;

            }
        }
    }
}

and this is my xml file till now:

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical" >

    <ImageView
        android:id="@+id/itemImage"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        android:src="@drawable/logo" />

    <RelativeLayout
        android:layout_width="fill_parent"
        android:layout_height="400dp"
        android:layout_marginTop="10dp"
        android:layout_weight="66496.79"
        android:orientation="horizontal" >

        <fragment
            android:id="@+id/map"
            class="com.google.android.gms.maps.MapFragment"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_marginRight="150dp" />

        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="170dp"
            android:orientation="vertical" >

            <Button
            android:id="@+id/messageBtn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:layout_alignParentRight="true"
            android:text="fffff" />

            <Button
                android:id="@+id/call"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_alignParentBottom="true"
                android:layout_alignParentRight="true"
                android:text="ffff" />

        <Button
            android:id="@+id/sms"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignRight="@+id/button1"
            android:layout_centerVertical="true"
            android:text="ffff" />
        <Button
            android:id="@+id/email"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignRight="@+id/button1"
            android:layout_centerVertical="true"
            android:text="fffff" />

        <Button
            android:id="@+id/navigate"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignLeft="@+id/button1"
            android:layout_alignParentEnd="false"
            android:layout_alignParentStart="false"
            android:layout_below="@+id/button1"
            android:layout_marginTop="14dp"
            android:text="ffffffffff" />
        </LinearLayout>
    </RelativeLayout>
</LinearLayout>

Answer 1

1. This will be managed automatically by the Maps component. You just have to call GoogleMap.setMyLocationEnabled(true);
   Important: Don't forget to call GoogleMap.setMyLocationEnabled(false) in the onPause of your activity/fragment!

2. You can use GoogleMap.setOnMyLocationChangeListener to add an handler that would be called each time the user position change.

3. You can use Geocoder to do reverse geocoding, but you will need a backend to be able to get results. Maybe the Google Play Service library provide said backend, but I am not sure as I never used this functionality

---

To search the name of a touched location (not tested) :

MyActivity extends Activity implements OnMapClickListener {

    Geocoder geocoder;

    @Override
    protected void onCreate(final Bundle savedInstanceState) {
        geocoder = new Geocoder(this);
    }

    @Override
    public void onMapClick(LatLng point) {
         List<Address> addresses = geocoder.getFromLocation(point.latitude, point.longitude, 1);

         if (adresses.length > 0) {
             Address address = addresses.get(0);
             Toast.makeText(this, address.getFeatureName(), Toast.LENGTH_SHORT).show();
         }
         else {
             Toast.makeText(this, "Not found!", Toast.LENGTH_SHORT).show();
         }
    }