Question

我想分享我到目前为止所准备的内容，同时就下一步所需的编码步骤寻求帮助和建议。

基于简短的基本java和android培训以及在线资源，我提出了以下具有以下目标的理论代码（理论上因为我还没有测试过）：

明确选择GPS提供商（GPS /手机/ wifi）以了解手机的位置
在textview中显示当前位置
通过3g连接到服务器
尽可能频繁地将纬度，经度和时间戳发送到服务器

以下是我准备的代码：

 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.telephony.TelephonyManager;
 import android.util.Log;
 import android.widget.TextView;
 import java.io.IOException;
 import java.io.PrintWriter;
 import java.net.Socket;
 import java.net.UnknownHostException;

 public class GpsActivity extends Activity {

private LocationManager lm;
private LocationListener locationListener;
public static TelephonyManager tm;
public static TextView tv;
public static Socket s;
public static PrintWriter out;


/**
 * Called when the activity is first created.
 */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
 /**
  * retrieve a reference to provide access to information about the telephony services on the device     
  */
    tm = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE); 
    setContentView(R.layout.main);
 /**
  * retrieve a reference to provide access to the system location services    
  */              
lm = (LocationManager)getSystemService(Context.LOCATION_SERVICE);    


/**
 * explicitly select the GPS provider, create a set of Criteria and let android choose the best provider available
 */

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 = lm.getBestProvider(criteria, true);
/**
 * This method takes in four parameters:
provider: The name of the provider with which you register
minTime: The minimum time interval for notifications, in milliseconds.
minDistance: The minimum distance interval for notifications, in meters.
listener: An object whose onLocationChanged() method will be called for each location update.
 */
locationListener = new MyLocationListener();
lm.requestLocationUpdates(provider, 0, 0, locationListener);

tv = (TextView) findViewById(R.id.textView1);
tv.setText("I currently have no Location Data.");

}

/**
 * Connects the Android Client to a given server
 * 
 * @param name
 *            The name of the remote server
 * @param port
 *            Port number to connect to at the remote server.
 * @throws IOException
 * @throws UnknownHostException
 */
public static void connect(String name, int port)
        throws UnknownHostException, IOException
{

    s = new Socket(name, port);
    out = new PrintWriter(s.getOutputStream(), true);
}

/**
 * Sends a string message to the server.
 * 
 * @param msg
 *            The message to be sent.
 * @throws IOException
 */
public static void send(String msg) throws IOException
{
    if (!s.isClosed() && msg != null)
    {
        out.println(msg);
        if (msg.contains("CMD_QUIT"))
        {
            out.close();
            s.close();
            Log.i("ServerConnection", "Client Disconnected.");
        }
    }
}


private class MyLocationListener implements LocationListener{

    @Override
    public void onLocationChanged(Location loc) {
        String txt = "Latitude:" + loc.getLatitude() + "/nLongitude:" + loc.getLongitude();
        Log.i("GeoLocation", "My current location is:\n " + txt);
        tv.setText("My current location is:\n" + txt);
        String msg = loc.getLongitude() + "\n" + loc.getLatitude() + "\n"
           + loc.getTime();

    try
        {
        connect("IP address", 27960);
        send("CMD_HELLO");
        send(msg);
        send("CMD_QUIT");
        } catch (UnknownHostException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        }



    @Override
    public void onProviderDisabled(String provider) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onProviderEnabled(String provider) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
        // TODO Auto-generated method stub

    }

}

}

请帮助

请注意以上代码是否符合给出的四个目标。
我如何能够达到我的第五个目标-----我希望Android应用程序开始触发连接到服务器并仅在手机（在汽车中使用）位于道路区域内时发送经度和纬度（比方说1km x 30m）。它会不断地听到它的位置，但是一旦它进入该区域就会开始发送到服务器，并且会一直发送，只有在它离开该区域后才会停止。

Answer 1

否。您要求操作系统提供最佳提供商。这将是明确lm.requestLocationUpdates(LocationManager.GPS_PROVIDER,
不会工作，因为您无法从侦听器更新文本视图。看看android.OS.Handler
从技术上讲，你遇到了这个问题，但是最好不要使用JSON或XML over HTTP而不是发明自己的协议。
是

对于5，创建两个位置，一个NorthWest位置和一个代表您的盒子的SouthEast位置。在您的onLocationChanged方法中，将新位置与角落进行比较，以便（l.lat＆gt; se.lat＆amp;＆amp; l.lat＆lt; nw.lat）和（l.lon＆lt; se。 lon＆amp; l.lon＆gt; nw.lon）其中“l”是回调的最新位置，“se”是你边界的东南角，“nw”是你的bounder的西北角。如果它符合上述4个条件，则发送到您的服务器。

android gps客户端仅在区域内向服务器发送坐标

1 个答案: