Android Studio：无法解析符号“ requestLocationUpdates”

Question

使用基本的GPS代码，新的Android Studio遇到了问题-我的意思是，到目前为止，其预览软件已经足够可靠，可以长时间使用。 所以这是给我问题的代码：

import android.app.Activity;
import android.app.AlertDialog; 
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.widget.TextView;

public class WhereAmI extends Activity implements LocationListener{

TextView lat, lon, alt, status;
Context myContext = this;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.whereami);
    lat = (TextView)findViewById(R.id.latTxt);
    lon = (TextView)findViewById(R.id.lonTxt);
    alt = (TextView)findViewById(R.id.altTxt);
    status = (TextView)findViewById(R.id.gpsStatus);
}

/* Use the LocationManager class to obtain GPS locations */
LocationManager LM = (LocationManager) getSystemService(LOCATION_SERVICE);
//Gather GPS data at a certain time interval.
LM.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1, 1f, myContext);
//Check to see if GPS is on
boolean isGPS = LM
        .isProviderEnabled(LocationManager.GPS_PROVIDER);

//If its off, request to turn it on.
if (isGPS == false)
{
    //Enable GPS pop-up notification.
    AlertDialog.Builder adb = new AlertDialog.Builder(myContext);

    // set title
    adb.setTitle("Enable GPS?");

    // set dialog message
    adb.setMessage("Enable GPS to get full function from the app.");
    adb.setCancelable(false);

    //Yes Button
    adb.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int id) {
            startActivityForResult(
                    new Intent(
                            android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS),
                    0);
        }
    });

    //No Button
    adb.setNegativeButton("No", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int id) {
            dialog.cancel();
        }
    });

    // create GPS Alert [Pop-up]
    AlertDialog alertDialog = adb.create();

    // show it
    alertDialog.show();
}
else
{
    //Added this so when the app gets refreshed it will show the true GPS info status.
    status.setText("GPS Status: Enabled");
}

@Override
public void onLocationChanged(Location location) {
    lat.setText("Latitude: " + location.getLatitude());
    lon.setText("Longitude: " + location.getLongitude());
    alt.setText("Altitude: " + location.getAltitude());
}

@Override
public void onStatusChanged(String s, int i, Bundle bundle) {

}

@Override
public void onProviderEnabled(String s) {
    status.setText("GPS Status: Enabled");
}

@Override
public void onProviderDisabled(String s) {

}
}

由于某种原因，它不断出现，无法解析requestLocationUpdates的符号。

还有其他人遇到这个问题或知道解决方案吗？

Answer 1

没有requestLocationUpdates()函数将Context作为输入。 以下是requestLocationUpdates（）函数的允许参数：

requestLocationUpdates(long minTime, float minDistance, Criteria criteria, PendingIntent intent)
requestLocationUpdates(long minTime, float minDistance, Criteria criteria, LocationListener listener, Looper looper)
requestLocationUpdates(String provider, long minTime, float minDistance, LocationListener listener)
requestLocationUpdates(String provider, long minTime, float minDistance, LocationListener listener, Looper looper)
requestLocationUpdates(String provider, long minTime, float minDistance, PendingIntent intent)

也请参见LocationManager页面。 希望这可以帮助。

更新

在oncreate()移动以下代码：

/* Use the LocationManager class to obtain GPS locations */
LocationManager LM = (LocationManager) getSystemService(LOCATION_SERVICE);
//Gather GPS data at a certain time interval.
LM.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1, 1f, myContext);
//Check to see if GPS is on
boolean isGPS = LM
        .isProviderEnabled(LocationManager.GPS_PROVIDER);

//If its off, request to turn it on.
if (isGPS == false)
{
    //Enable GPS pop-up notification.
    AlertDialog.Builder adb = new AlertDialog.Builder(myContext);

    // set title
    adb.setTitle("Enable GPS?");

    // set dialog message
    adb.setMessage("Enable GPS to get full function from the app.");
    adb.setCancelable(false);

    //Yes Button
    adb.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int id) {
            startActivityForResult(
                    new Intent(
                            android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS),
                    0);
        }
    });

    //No Button
    adb.setNegativeButton("No", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int id) {
            dialog.cancel();
        }
    });

    // create GPS Alert [Pop-up]
    AlertDialog alertDialog = adb.create();

    // show it
    alertDialog.show();
}
else
{
    //Added this so when the app gets refreshed it will show the true GPS info status.
    status.setText("GPS Status: Enabled");
}