通过短信发送GPS坐标

我是android的新手。 我正在尝试开发一个应用程序，用于获取用户当前的GPS坐标并通过短信发送到硬编码的数字。 我正在使用两个活动，第一个有进度条和一些文本（Processing，Please wait），它实际上是在后台获取GPS坐标。 第二个是从第一个活动接收坐标并发送短信。 我面临的问题是，在MainActivity.java文件中，条件if（纬度> 0）永远不会满足，因为gps通常需要一些时间来获取坐标，我不能去第二个活动。 我附上代码，请帮帮我。 如果你愿意，你可以编辑代码。 提前致谢。

package com.shaji.smartcab; import com.shaji.smartcab.MainActivity; import com.shaji.smartcab.MyLocationListener; import com.shaji.smartcab.R; import android.os.Bundle; import android.app.Activity; import android.view.Menu; import android.widget.TextView; import android.widget.Toast; import android.location.LocationListener; import android.content.Context; import android.content.Intent; import android.location.LocationManager; public class MainActivity extends Activiy{ double lat; double lon; String coordinates; String coor; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); TextView tv= (TextView) findViewById(R.id.textView1); LocationManager mlocManager=null; LocationListener mlocListener; mlocManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE); mlocListener = new MyLocationListener(); mlocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 600,10, mlocListener); if (mlocManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) { if(MyLocationListener.latitude>0) { lat = MyLocationListener.latitude; lon = MyLocationListener.longitude; tv.setText("m fetching coordinates"); coordinates= lat+","+lon; Intent intent = new Intent(MainActivity.this, Sec.class); intent.putExtra(coor, coordinates); startActivity(intent); //tv1.setText("Latitude:" + MyLocationListener.latitude + ",Longitude:" + MyLocationListener.longitude ); }} else { Context context = getApplicationContext(); CharSequence text = "Please turn ON GPS and Try again Later!"; int duration = Toast.LENGTH_SHORT; Toast toast = Toast.makeText(context, text, duration); toast.show(); tv.setText(" "); } }; @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.main, menu); return true; }} 

enter code here包com.shaji.smartcab;

 import android.location.Location; import android.location.LocationListener; import android.os.Bundle; public class MyLocationListener implements LocationListener { public static double latitude; public static double longitude; @Override public void onLocationChanged(Location loc) { loc.getLatitude(); loc.getLongitude(); latitude=loc.getLatitude(); longitude=loc.getLongitude(); } @Override public void onProviderDisabled(String provider) { //print "Currently GPS is Disabled"; } @Override public void onProviderEnabled(String provider) { //print "GPS got Enabled"; } @Override public void onStatusChanged(String provider, int status, Bundle extras) { } } //this is the second activity. package com.shaji.smartcab; import com.shaji.smartcab.R; import android.app.Activity; import android.os.Bundle; import android.telephony.SmsManager; import android.view.View; import android.widget.Button; import android.widget.Toast; public class Sec extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.second); final String sms = (String) getIntent().getExtras().get("coor"); Button c = (Button) findViewById(R.id.button1); c.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View arg0) { String phoneNo = "03136166588"; //String sms = "coordinates"; try { SmsManager smsManager = SmsManager.getDefault(); smsManager.sendTextMessage(phoneNo, null, sms, null, null); Toast.makeText(getApplicationContext(), "Request Sent!", Toast.LENGTH_LONG).show(); } catch (Exception e) { Toast.makeText(getApplicationContext(), " Error, please try again later!", Toast.LENGTH_LONG).show(); e.printStackTrace(); } }}); }} 

Answer 1

我认为问题是，在调用下一个Activity之前，没有完成位置更新。

在获得更新之前，请使用3个提供商之一获取坐标。 请参阅以下代码。

 private Location getUserLocation() { location_manager = (LocationManager) getSystemService(LOCATION_SERVICE); if (location_manager != null) { List provider=location_manager .getAllProviders(); Location location = null; for(int i=0;i