android：无法在谷歌地图v2上显示mylocation

Question

我无法成功运行该应用， 该应用程序已编译没有错误，但一旦打开就崩溃 一切看起来都不错，但并不是这样 请帮我解决代码有什么问题。

这是主Java文件：

package com.example.alchemist.myapplication;

import android.content.Context;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;

import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;

public class MapsActivity1 extends FragmentActivity{

    private GoogleMap mMap; // Might be null if Google Play services APK is not available.
    LocationManager lm;
    String locprovider = LocationManager.GPS_PROVIDER;
    Location location;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps_activity1);
        LocationManager lm = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
        location = lm.getLastKnownLocation(locprovider);

        setUpMapIfNeeded();
    }

    @Override
    protected void onResume() {
        super.onResume();
        setUpMapIfNeeded();
    }

    private void setUpMapIfNeeded() {
        // Do a null check to confirm that we have not already instantiated the map.
        if (mMap == null) {
            // Try to obtain the map from the SupportMapFragment.
            mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map))
                    .getMap();
            // Check if we were successful in obtaining the map.
            if (mMap != null) {
                setUpMap();
            }
        }
    }


    private void setUpMap() {
        //mMap.setMyLocationEnabled(true);
        lm.requestLocationUpdates(locprovider, 0, 0, loclistener);
        LatLng ltlg = new LatLng(location.getLatitude(), location.getLongitude());

        mMap.addMarker(new MarkerOptions().position(ltlg).title("Me"));
    }


    private LocationListener loclistener = new LocationListener() {
        @Override
        public void onLocationChanged(Location location) {
        showLocOnMap(location);
         }

        @Override
        public void onStatusChanged(String s, int i, Bundle bundle) {

        }

        @Override
        public void onProviderEnabled(String s) {

        }

        @Override
        public void onProviderDisabled(String s) {

        }
    };

    public void showLocOnMap(Location location) {
        mMap.clear();
        MarkerOptions mrkropt = new MarkerOptions();
        mrkropt.position(new LatLng(location.getLatitude(),location.getLongitude()));
        mrkropt.title("Me again");
        mMap.addMarker(mrkropt);
        mMap.animateCamera(CameraUpdateFactory. newLatLngZoom(new LatLng(location.getLatitude(), location.getLongitude()), 16));
    }


}

这是Xml文件：

<fragment xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/map"
    tools:context=".MapsActivity1"
    android:name="com.google.android.gms.maps.SupportMapFragment" />

这里是Android Manifest File：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.alchemist.myapplication" >

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MapsActivity1"
            android:label="@string/title_activity_maps_activity1" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <meta-data
            android:name="com.google.android.gms.version"
            android:value="@integer/google_play_services_version" />
        <meta-data
            android:name="com.google.android.maps.v2.API_KEY"
            android:value="@string/google_maps_key" />
    </application>

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" />
    <!--
         The ACCESS_COARSE/FINE_LOCATION permissions are not required to use
         Google Maps Android API v2, but are recommended.
    -->
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

</manifest>