Android Google地图无法正常加载

Question

！[package com.example.mytt.cardguide;

import java.util.List;
import java.util.Locale;

import android.app.Activity;
import android.location.Address;
import android.location.Geocoder;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.Window;
import android.widget.Button;

import com.example.mytt.R;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.MapFragment;
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 CardGuide_MainActivity extends Activity {

    Button btnShowLocation;
    // GPSTracker class
    GPSTracker gps;
    GoogleMap map;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);

        this.requestWindowFeature(Window.FEATURE_NO_TITLE);

        setContentView(R.layout.cardguide);


        // Get a handle to the Map Fragment
        final GoogleMap map = ((MapFragment) getFragmentManager()
                .findFragmentById(R.id.map)).getMap();


         Button btnShowLocation = (Button) findViewById(R.id.showlocation_btn);

        // show location button click event
            btnShowLocation.setOnClickListener(new View.OnClickListener() {

                @Override
                public void onClick(View arg0) {        
                    // create class object
                    gps = new GPSTracker(CardGuide_MainActivity.this);

                    // check if GPS enabled     
                    if(gps.canGetLocation()){

                        double latitude = gps.getLatitude();
                        double longitude = gps.getLongitude();

                          LatLng mylocation = new LatLng(latitude,longitude);

                          String strAdd = "";
                          Geocoder geocoder = new Geocoder(CardGuide_MainActivity.this, Locale.getDefault());
                          try {
                              List<Address> addresses = geocoder.getFromLocation(latitude, longitude, 1);
                              if (addresses != null) {
                                  Address returnedAddress = addresses.get(0);
                                  StringBuilder strReturnedAddress = new StringBuilder("");

                                  for (int i = 0; i < returnedAddress.getMaxAddressLineIndex(); i++) {
                                      strReturnedAddress.append(returnedAddress.getAddressLine(i)).append("\n");
                                  }
                                  strAdd = strReturnedAddress.toString();
                                  Log.w("My Current loction address", "" + strReturnedAddress.toString());
                              } else {
                                  Log.w("My Current loction address", "No Address returned!");
                              }
                          } catch (Exception e) {
                              e.printStackTrace();
                              Log.w("My Current loction address", "Canont get Address!");
                          }



                        map.moveCamera(CameraUpdateFactory.newLatLngZoom(mylocation, 13));
                      Marker marker = map.addMarker(new MarkerOptions()
                      .position(mylocation)
                      .title(""+strAdd+""));

                      marker.showInfoWindow();


                        // \n is for new line
                        //Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();  
                    }else{
                        // can't get location
                        // GPS or Network is not enabled
                        // Ask user to enable GPS/network in settings
                        gps.showSettingsAlert();
                    }

                }
            });



    }
    }][3]

当我点击图片视图时，地图会按原样加载，但点击“显示我的位置”按钮后，地图会消失，但当前位置的地址会按原样显示。

我不知道为什么地图会在点击按钮后消失。

我甚至检查了也不为空的地图对象......

Answer 1

Google API控制台上的API密钥和软件包名称不匹配。