Question

我正在尝试制作Android谷歌地图，地图没有显示，并且出现“无法确定位置”的吐司，这意味着未检测到位置（= null）所以我有2个问题：

1-地图未显示

2-未检测到位置

我有2个Java文件

MyMapLocationActivity.java

    package com.joshclemm.android.tutorial;

import android.os.Bundle;
import android.widget.Toast;

import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapView;
import com.google.android.maps.MyLocationOverlay;

public class MyMapLocationActivity extends MapActivity {

    private MapView mapView;
    private MyLocationOverlay myLocationOverlay;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // main.xml contains a MapView
        setContentView(R.layout.main); 

        // extract MapView from layout
        mapView = (MapView) findViewById(R.id.mapview);
        mapView.setBuiltInZoomControls(true);

        // create an overlay that shows our current location
        myLocationOverlay = new FixedMyLocationOverlay(this, mapView);

        // add this overlay to the MapView and refresh it
        mapView.getOverlays().add(myLocationOverlay);
        mapView.postInvalidate();

        // call convenience method that zooms map on our location
        zoomToMyLocation();
    }

    @Override
    protected void onResume() {
        super.onResume();
        // when our activity resumes, we want to register for location updates
        myLocationOverlay.enableMyLocation();
    }

    @Override
    protected void onPause() {
        super.onPause();
        // when our activity pauses, we want to remove listening for location updates
        myLocationOverlay.disableMyLocation();
    }

    /**
     * This method zooms to the user's location with a zoom level of 10.
     */
    private void zoomToMyLocation() {
        GeoPoint myLocationGeoPoint = myLocationOverlay.getMyLocation();

        //System.out.println("myLocationGeoPoint is " +myLocationGeoPoint);
        if(myLocationGeoPoint != null) {
            System.out.println("Gowa !null");
            mapView.getController().animateTo(myLocationGeoPoint);
            mapView.getController().setZoom(10);
        }
        else {
            Toast.makeText(this, "Cannot determine location", Toast.LENGTH_SHORT).show();
        }
    }

    @Override
    protected boolean isRouteDisplayed() {
        return false;
    }
}

FixedMyLocationOverlay.java

package com.joshclemm.android.tutorial;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Point;
import android.graphics.Paint.Style;
import android.graphics.drawable.Drawable;
import android.location.Location;

import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapView;
import com.google.android.maps.MyLocationOverlay;
import com.google.android.maps.Projection;

/**
 * Fixes bug with some phone's location overlay class (ie Droid X).
 * Essentially, it attempts to use the default MyLocationOverlay class,
 * but if it fails, we override the drawMyLocation method to provide
 * an icon and accuracy circle to mimic showing user's location.  Right
 * now the icon is a static image.  If you want to have it animate, modify
 * the drawMyLocation method.
 */
public class FixedMyLocationOverlay extends MyLocationOverlay {

    private boolean bugged = false;

    private Drawable drawable;
    private Paint accuracyPaint;
    private Point center;
    private Point left;
    private int width;
    private int height;

    public FixedMyLocationOverlay(Context context, MapView mapView) {
        super(context, mapView);
    }

    @Override
    protected void drawMyLocation(Canvas canvas, MapView mapView,
            Location lastFix, GeoPoint myLocation, long when) {
        if(!bugged) {
            try {
                super.drawMyLocation(canvas, mapView, lastFix, myLocation, when);
            } catch (Exception e) {
                // we found a buggy phone, draw the location icons ourselves
                bugged = true;
            }
        }

        if(bugged) {
            if(drawable == null) {

                accuracyPaint = new Paint();
                accuracyPaint.setAntiAlias(true);
                accuracyPaint.setStrokeWidth(2.0f);

                drawable = mapView.getContext().getResources().getDrawable(R.drawable.ic_maps_indicator_current_position);
                width = drawable.getIntrinsicWidth();
                height = drawable.getIntrinsicHeight();
                center = new Point();
                left = new Point();
            }

            Projection projection = mapView.getProjection();
            double latitude = lastFix.getLatitude();
            double longitude = lastFix.getLongitude();
            float accuracy = lastFix.getAccuracy();

            float[] result = new float[1];

            Location.distanceBetween(latitude, longitude, latitude, longitude + 1, result);
            float longitudeLineDistance = result[0];

            GeoPoint leftGeo = new GeoPoint((int)(latitude*1e6), (int)((longitude-accuracy/longitudeLineDistance)*1e6));
            projection.toPixels(leftGeo, left);
            projection.toPixels(myLocation, center);
            int radius = center.x - left.x;

            accuracyPaint.setColor(0xff6666ff);
            accuracyPaint.setStyle(Style.STROKE);
            canvas.drawCircle(center.x, center.y, radius, accuracyPaint);

            accuracyPaint.setColor(0x186666ff);
            accuracyPaint.setStyle(Style.FILL);
            canvas.drawCircle(center.x, center.y, radius, accuracyPaint);

            drawable.setBounds(center.x - width/2, center.y - height/2, center.x + width/2, center.y + height/2);
            drawable.draw(canvas);
        }
    }
}

清单文件

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.joshclemm.android.tutorial"
      android:versionCode="1"
      android:versionName="1.0">

    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".MyMapLocationActivity"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    <!-- Make sure the uses-library line is inside the application tag -->
    <uses-library android:name="com.google.android.maps" />
    </application>
     <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="8" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
</manifest>

布局的XML文件：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <com.google.android.maps.MapView
        android:id="@+id/mapview" android:layout_width="fill_parent"
        android:layout_height="wrap_content" android:clickable="true"
        android:apiKey="AIzaSyCx7eq9mnY609bDebfAEeBLx8L2Exw8J30" />
</LinearLayout>

这是完全出现的图像

enter image description here

Answer 1

我看到你的MyMapLocationActivity.java是2010年的一个示例片段，可能是为Google Maps Android v1编写的。在v2中，事情的表现略有不同。

此代码段应该可以帮助您前进。请注意，在尝试缩放到当前位置之前，请使用OnGlobalLayoutListener检查布局是否已完成。

public class ShowMapTest extends FragmentActivity {
private GoogleMap mMap;
private LinearLayout layout;
private LocationManager lm = null;
private LatLng mySpot = null;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.nearbymapview);

    lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    Criteria criteria = new Criteria();
    criteria.setAccuracy(Criteria.ACCURACY_FINE);
    Location loc = lm.getLastKnownLocation(lm.getBestProvider(criteria, false));

    if (loc != null) {
        mySpot = new LatLng(loc.getLatitude(), loc.getLongitude());
    } else {
        criteria.setAccuracy(Criteria.ACCURACY_FINE);
        loc = lm.getLastKnownLocation(lm.getBestProvider(criteria, false));

        if (loc == null) {
            mySpot = new LatLng(39.952451,-75.163664); // city hall by default
        }
    }

    // check if already instantiated
    if (mMap == null) {
        mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap();
        mMap.setMyLocationEnabled(true);
        layout = (LinearLayout)findViewById(R.id.LinearLayout01);
        ViewTreeObserver vto = layout.getViewTreeObserver();
        vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                layout.getViewTreeObserver().removeGlobalOnLayoutListener(this);
                // Center & zoom the map after map layout completes
                mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(mySpot, 15));
            }
        });
    } else {
        mMap.clear();
    }

    // check if got map
    if (mMap == null) {
        Log.e("Couldn't get map fragment!", "No map fragment");
        return;
    }

nearbymapview.xml：

<?xml version="1.0" encoding="UTF-8"?>
<LinearLayout android:id="@+id/LinearLayout01"
    android:layout_above="@+id/mapview" xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_height="fill_parent" android:layout_width="fill_parent"
    android:orientation="vertical">
    <RelativeLayout android:id="@+id/RelativeLayout01"
        android:layout_width="wrap_content" android:layout_height="wrap_content"
        android:paddingLeft="4sp" android:paddingTop="4sp"
        android:paddingRight="6sp">
        <TextView android:id="@+id/TextViewT1"
            android:layout_height="wrap_content" android:layout_width="wrap_content"
            android:layout_alignParentLeft="true" android:layout_marginLeft="2sp"
            android:textSize="20sp" android:textStyle="bold" android:text="Test Map"></TextView>
        <TextView android:id="@+id/TextViewT3"
            android:layout_width="wrap_content" android:layout_height="wrap_content"
            android:layout_alignParentRight="true" android:textSize="20sp"
            android:textStyle="bold"></TextView>
    </RelativeLayout>
    <fragment
        android:id="@+id/map"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:name="com.google.android.gms.maps.SupportMapFragment"/>
</LinearLayout>

清单中的

：

<activity
    android:name="ShowMapTest"
    android:finishOnTaskLaunch="true"
    android:launchMode="singleTop" >
</activity>

...

 <meta-data
        android:name="com.google.android.maps.v2.API_KEY"
        android:value="YOUR_KEY_HERE"/>

Google地图未显示且未检测到位置

1 个答案: