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  • GPS开发报错provider为空问题解决

      本人初学Android,最近尝试做一个GPS练习,通过上网查找资料自己学习开发,但是测试过程中出现问题 provider的值一直为空,上网查找资料有说没加权限的 有说需要加“locationManager.setTestProviderEnabled("gps", true);”这行代码的,我都试验了一遍但是仍然报错。困扰了很长时间,最后终于发现问题所在跟大家分享一下希望对大家有帮助。

    我的问题是出在权限上,我最开始找到的资料上权限是这样加的

    <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
     <uses-permission android:name="android.permission.ACCESS_FIND_LOCATION" />注意这行代码

    后来发现应该是

    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
        <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />注意是FINE而不是FIND

    修改之后 问题解决,如获重释一般的感觉。下面把我的测试通过的代码分享一下 希望对学习GPS的朋友有所帮助。

    我的GPSActivitys

    import android.app.Activity;
    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.widget.TextView;

    public class GPSActivity extends Activity {
        /** Called when the activity is first created. */
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main);
           
            LocationManager locationManager;
            String serviceName = Context.LOCATION_SERVICE;
            locationManager = (LocationManager)getSystemService(serviceName);
            //String provider = LocationManager.GPS_PROVIDER;
           
            Criteria criteria = new Criteria();
            criteria.setAccuracy(Criteria.ACCURACY_FINE);
            criteria.setAltitudeRequired(false);
            criteria.setBearingRequired(false);
            criteria.setCostAllowed(true);
            criteria.setPowerRequirement(Criteria.POWER_LOW);
            String provider = locationManager.getBestProvider(criteria, true);
           
            Location location = locationManager.getLastKnownLocation(provider);
            //updateWithNewLocation(location);
            locationManager.requestLocationUpdates(provider, 2000, 10,
                            locationListener);
            updateWithNewLocation(location);
        }
       
        private final LocationListener locationListener = new LocationListener() {
      public void onLocationChanged(Location location) {
       updateWithNewLocation(location);
      }

      public void onProviderDisabled(String provider) {
       updateWithNewLocation(null);
      }

      public void onProviderEnabled(String provider) {
      }

      public void onStatusChanged(String provider, int status, Bundle extras) {
      }
     };
     
     private void updateWithNewLocation(Location location) {
      String latLongString;
      TextView myLocationText;
      myLocationText = (TextView) findViewById(R.id.myLocationText);//这个自己设计一个TextViews
      if (location != null) {
       double lat = location.getLatitude();
       double lng = location.getLongitude();
       latLongString = "纬度:" + lat + "\n经度:" + lng;
      } else {
       latLongString = "无法获取地理信息";
      }
      myLocationText.setText("您当前的位置是:\n" + latLongString);
     }
    }

     

    AndroidManifest.xml代码如下

    <?xml version="1.0" encoding="utf-8"?>
    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="com.gzsk.gps"
          android:versionCode="1"
          android:versionName="1.0">
        <uses-sdk android:minSdkVersion="7" />

        <application android:icon="@drawable/icon" android:label="@string/app_name">
            <activity android:name=".GPSActivity"
                      android:label="@string/app_name">
                <intent-filter>
                    <action android:name="android.intent.action.MAIN" />
                    <category android:name="android.intent.category.LAUNCHER" />
                </intent-filter>
            </activity>

        </application>
        <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
     <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />  
       
    </manifest>

     

     

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  • 原文地址:https://www.cnblogs.com/huanglong/p/2109689.html
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