在屏幕上显示GPS位置- Android

Question

我在这里遵循指南:http://www.firstdroid.com/2010/04/29/android-development-using-gps-to-get-current-location-2/

我正试图使一个安卓应用程序，简单地得到设备的GPS坐标，并显示在屏幕上。当我telnet到模拟器并输入"geo fix 30.0 30.0"时，我的代码在模拟器中工作得很好，但是当我在手机上使用它时，它永远不会得到坐标。我的GPS工作正常，因为我打开地图，它有我的确切位置。所以下面的代码一定有问题:

import java.io.IOException;
import android.app.Activity;
import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;
import android.widget.Toast;
public class BusAppActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        /* Use the LocationManager class to obtain GPS locations */
        LocationManager locManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
        LocationListener locListener = new MyLocationListener();
        locManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, locListener);
    }
   /* To test in the emulator, use the telnet commands:
    * telnet localhost 5554
    * geo fix 30.0 30.0 */
    /* Class My Location Listener */
    public class MyLocationListener implements LocationListener
    {
        TextView tv = (TextView) findViewById(R.id.textview);
        @Override
        public void onLocationChanged(Location loc){
            Log.d("tag", "Finding Latitude");
            double lat = loc.getLatitude();
            Log.d("tag", "Lat: "+String.valueOf(lat));
            Log.d("tag", "Finding Longitude");
            double lon = loc.getLongitude();
            Log.d("tag", "Lon: "+String.valueOf(lon));
            String Text = "My current location is: " +
            "nLatitude = " + lat +
            "nLongitude = " + lon;
            // Display location
            tv.setText(Text);
        }
        @Override
        public void onProviderDisabled(String provider){
            Toast.makeText(getApplicationContext(), "Gps Disabled", Toast.LENGTH_SHORT ).show();
        }
        @Override
        public void onProviderEnabled(String provider){
            Toast.makeText(getApplicationContext(), "Gps Enabled", Toast.LENGTH_SHORT).show();
        }
        @Override
        public void onStatusChanged(String provider, int status, Bundle extras){
        }
    }
}

这是我的清单:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="gsingh.busapp"
    android:versionCode="1"
    android:versionName="1.0" >
    <uses-sdk android:minSdkVersion="8" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"></uses-permission>
    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:label="@string/app_name"
            android:name=".BusAppActivity" >
            <intent-filter >
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>

如果不太麻烦的话，也许有人可以构建这个项目并在他们的手机上试用?所有需要添加的是将唯一的textview标记为"textview"

Answer 1

我找不到你的代码有任何问题。同样的代码对我来说工作得很好。

我认为这可能是你的文本视图(layout_height或其他东西)的问题。