我已经看到了很多这类问题的答案，但它与我的任务无关。我正在尝试在后台获取gps位置，但我在Cant Create Handler Inside Thread That Has Not Called Looper Prepare in Android中的mlocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, mlocListener);例外。
public class GPSLocation extends AsyncTask<Void, Void, Void>
{
@Override
protected void onPreExecute()
{
super.onPreExecute();
progressDialog = new ProgressDialog(RoadMaintenanceActivity.this);
progressDialog.setCancelable(true);
progressDialog.setMessage("Getting GPS Location...");
progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
progressDialog.setProgress(1);
progressDialog.show();
}
@Override
protected void onProgressUpdate(Void... values) {
super.onProgressUpdate(values);
// Things to be done while execution of long running operation is in progress. For example updating ProgessDialog
}
@Override
protected void onPostExecute(Void result)
{
progressDialog.cancel();
}
@Override
protected Void doInBackground(Void... params) {
boolean isGps = false;
while(!isGps)
{
LocationManager mlocManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
LocationListener mlocListener = new MyLocationListener();
mlocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, mlocListener);
if(longitude !=0 && latitude!=0)
{
isGps = true;
sendSMS();
}
}
return null;
}
}
我不确定为什么我们不能在doBackground（）方法中调用它。
感谢您的帮助。
答案 0 :(得分：5)
最后我想出了问题，我认为这会对像我这样的人有所帮助
public class GPSLocation extends AsyncTask<Void, Void, Void>
{
boolean running =true;
@Override
protected void onPreExecute()
{
super.onPreExecute();
progressDialog = new ProgressDialog(RoadMaintenanceActivity.this);
progressDialog.setOnCancelListener(new DialogInterface.OnCancelListener(){
public void onCancel(DialogInterface dialog) {
getgps.cancel(true);
}
});
LocationManager mlocManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
LocationListener mlocListener = new MyLocationListener();
mlocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, mlocListener);
progressDialog.setCancelable(true);
progressDialog.setMessage("Getting GPS Location...");
progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
progressDialog.setProgress(1);
progressDialog.show();
}
@Override
protected void onProgressUpdate(Void... values) {
super.onProgressUpdate(values);
// Things to be done while execution of long running operation is in progress. For example updating ProgessDialog
}
@Override
protected void onPostExecute(Void result)
{
progressDialog.cancel();
}
@Override
protected Void doInBackground(Void... params) {
boolean isDataSubmitted = false;
while(!isDataSubmitted)
{
if(longitude !=0 && latitude!=0)
{
sendSMS();
isDataSubmitted = true;
}
}
return null;
}
}
通过在onPreExecute()中设置Locationmanager，异常将从我的应用程序中删除。我们可以在onpreexecute中获取gps而不是doinbackground()。
答案 1 :(得分：3)
你不能这样做.mlocListener需要一个Looper线程才能运行。
doInBackground中的调用Looper.prepare();
所以你的代码会变成这样的东西。
@Override
protected Void doInBackground(Void... params) {
Looper.myLooper().prepare();
boolean isGps = false;
-----------------
答案 2 :(得分：1)
这似乎适合我此刻想要做的事情。你有机会向我展示完整的消息来源吗？我目前已将其用于我的代码，但我想知道你是如何获得GPS协议并启动异步的
ProgressDialog progressDialog;
double longitude, latitude;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_confirm_screen);
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
Boolean locationCheck = sp.getBoolean("LOCATION", false);
if(locationCheck){
}
else
{
sendEmail();
playSound();
}
}
public class GPSLocation extends AsyncTask<Void, Void, Void>
{
boolean running =true;
@Override
protected void onPreExecute()
{
super.onPreExecute();
progressDialog = new ProgressDialog(ConfirmScreen.this);
progressDialog.setOnCancelListener(new DialogInterface.OnCancelListener(){
public void onCancel(DialogInterface dialog) {
getgps.cancel(true);
}
});
LocationManager mlocManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
LocationListener mlocListener = new MyLocationListener();
mlocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, mlocListener);
progressDialog.setCancelable(true);
progressDialog.setMessage("Getting GPS Location...");
progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
progressDialog.setProgress(1);
progressDialog.show();
}
@Override
protected void onProgressUpdate(Void... values) {
super.onProgressUpdate(values);
// Things to be done while execution of long running operation is in progress. For example updating ProgessDialog
}
@Override
protected void onPostExecute(Void result)
{
progressDialog.cancel();
}
@Override
protected Void doInBackground(Void... params) {
boolean isDataSubmitted = false;
while(!isDataSubmitted)
{
if(longitude !=0 && latitude!=0)
{
sendEmail();
isDataSubmitted = true;
}
}
return null;
}
}
public void backHome(View view)
{
Intent intent = new Intent (this, MainScreen.class);
startActivity(intent);
}
// Method to start playing and looping a sound.
public void playSound()
{
MediaPlayer clickSound = MediaPlayer.create(this, R.raw.warning);
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
Boolean soundCheck = sp.getBoolean("SOUND", false);
if (soundCheck)
{
clickSound.start();
}
}// method end
public void sendEmail()
{
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
String nameValue = sp.getString("NAME", "failed to get name");
String emailValue = sp.getString("EMAIL", "failed to get email");
Intent i = new Intent(Intent.ACTION_SEND);
i.setType("message/rfc822");
i.putExtra(Intent.EXTRA_EMAIL, new String[]{emailValue});
i.putExtra(Intent.EXTRA_SUBJECT, "Email sent from DON'T PANIC - A Chris O'Brien Project");
i.putExtra(Intent.EXTRA_TEXT, "Hi there\n" + nameValue + " is in mortal danger. They didn't include co-ords as they assume you know where they are..\nKind Regards\nDon't Panic! \n\n\n");
try
{ startActivity(Intent.createChooser(i, "Send mail...."));
}
catch (android.content.ActivityNotFoundException ex){
Toast.makeText(ConfirmScreen.this, "There are no email clients installed or set up", Toast.LENGTH_SHORT).show();
}
}
public void sendEmail(String a, String b, String c)
{
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
String nameValue = sp.getString("NAME", "failed to get name");
String emailValue = sp.getString("EMAIL", "failed to get email");
Intent i = new Intent(Intent.ACTION_SEND);
i.setType("message/rfc822");
i.putExtra(Intent.EXTRA_EMAIL, new String[]{emailValue});
i.putExtra(Intent.EXTRA_SUBJECT, "Email sent from DON'T PANIC - A Chris O'Brien Project");
i.putExtra(Intent.EXTRA_TEXT, "Hi there\n" + nameValue + " is in mortal danger. Please see the co-ords attached and run to their rescue!" +
" If you don't see any co-ords, they didn't check the box and assume you know where they are.\nKind Regards\nDon't Panic! \n\n\n" +
a + b + c);
try
{ startActivity(Intent.createChooser(i, "Send mail...."));
}
catch (android.content.ActivityNotFoundException ex){
Toast.makeText(ConfirmScreen.this, "There are no email clients installed or set up", Toast.LENGTH_SHORT).show();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_confirm_screen, menu);
return true;
}
}