我正在开发地图应用程序。
在编辑文本字段中，应用程序会自动提取用户位置。如果未获取位置，则必须打开一个对话框，显示“无法获取位置，是否要关闭应用程序？”。
当按下后退按钮时，onBackPressed（）可用于关闭应用程序。
但我希望在应用程序运行之间发生这种情况。
以下是我必须使用它的活动。
Tripdetails.java
public class TripDetails extends Activity implements LocationListener {
EditText pres_location, destination_et;
protected LocationManager locationManager;
protected Context context;
ImageView destination_icon;
Button done, cancel;
Double deslat, deslong;
String veh;
String provider;
Location location;
EditText vechile;
SharedPreferences pref;
// protected String latitude,longitude;
// protected boolean gps_enabled,network_enabled;
String logDate, logLatitude = "no data avilable",
logLongtitude = "no data avilable",
logAddress = "no data avilable";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_trip_details);
vechile = (EditText) findViewById(R.id.vechile_number);
veh = vechile.getText().toString();
pres_location = (EditText) findViewById(R.id.present_location);
destination_icon = (ImageView) findViewById(R.id.destination_icon);
destination_et = (EditText) findViewById(R.id.et_destination);
done = (Button) findViewById(R.id.btn_done);
cancel = (Button) findViewById(R.id.btn_cancel);
pref = getSharedPreferences("gps", Context.MODE_PRIVATE);
//gps checking
LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
if (locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
Toast.makeText(this, "GPS is Enabled in your device", Toast.LENGTH_SHORT).show();
} else {
showGPSDisabledAlertToUser();
}
done.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(getApplication(),"Alert has been sent to your emergency contact.",Toast.LENGTH_SHORT).show();
new Thread(new Runnable() {
public void run() {
if ((!pres_location.getText().toString().equals("")) && (!destination_et.getText().toString().equals("")) && (!vechile.getText().toString().equals(""))) {
String a = pref.getString("mobile", "");
String a2 = pref.getString("mobile2", "");
String name = pref.getString("Name", "");
/*SmsManager smsManager = SmsManager.getDefault();
smsManager.sendTextMessage(a, null, "Your Friend " + name + " " + "travelling from " + pres_location.getText().toString()
+ " " + "to:" + destination_et.getText().toString()
+ ", in V.No " + vechile.getText().toString()
, null, null);
smsManager.sendTextMessage(a2, null, "Your Friend " + name + " " + "travelling from " + pres_location.getText().toString()
+ " " + "to:" + destination_et.getText().toString()
+ ", in V.No " + vechile.getText().toString()
, null, null);
*/
Intent in = new Intent(TripDetails.this,
MapsActivityConnect.class);
in.putExtra("deslatitude", deslat);
in.putExtra("deslongitude", deslong);
in.putExtra("srclatitude", location.getLatitude());
in.putExtra("srclongitude", location.getLongitude());
startActivity(in);
} else {
runOnUiThread(new Runnable() {
public void run() {
Toast.makeText(getApplication(), "Please check your network", Toast.LENGTH_SHORT).show();
}
});
}
}
}).start();
}
});
destination_icon.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
new Thread(new Runnable() {
public void run() {
Intent in = new Intent(TripDetails.this,
MapsActivity.class);
startActivity(in);
}
}).start();
}
});
// Getting LocationManager objectlatitude
locationManager = (LocationManager)
getSystemService(Context.LOCATION_SERVICE);
// Creating an empty criteria object
Criteria criteria = new Criteria();
// Getting the name of the provider that meets the criteria
provider = locationManager.getBestProvider(criteria, true);
if (provider != null && !provider.equals(""))
{
// Get the location from the given provider
location = locationManager.getLastKnownLocation(provider);
locationManager.requestLocationUpdates(provider, 2000, 0, this);
if (location != null)
onLocationChanged(location);
else
Toast.makeText(getBaseContext(), "Location can't be retrieved", Toast.LENGTH_SHORT).show();
} else
{
Toast.makeText(getBaseContext(), "No Provider Found", Toast.LENGTH_SHORT).show();
onBackPressed();
}
Spinner dropdown = (Spinner) findViewById(R.id.spinner1);
String[] items = new String[]{"Car", "Bus", "Bike", "Train", "Flight"};
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_dropdown_item, items);
dropdown.setAdapter(adapter);
cancel.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent in = new Intent(TripDetails.this,
Sign_in.class);
startActivity(in);
}
});
}
@Override
public void onLocationChanged(Location location) {
Bundle extras = getIntent().getExtras();
if (extras != null) {
deslat = extras.getDouble("latitude");
deslong = extras.getDouble("longitude");
destination_et.setText(getCompleteAddressString(deslat, deslong));
}
pres_location.setText(getCompleteAddressString(location.getLatitude(), location.getLongitude()));
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
Log.d("Latitude", "status");
}
@Override
public void onProviderEnabled(String provider) {
Log.d("Latitude", "Enable");
}
@Override
public void onProviderDisabled(String provider) {
Log.d("Latitude", "disable");
}
private String getCompleteAddressString(double LATITUDE, double LONGITUDE) {
String loc = null;
Address returnedAddress = null;
// geocode object is created
Geocoder geocoder = new Geocoder(this, Locale.getDefault());
try {
// address is derived
List<Address> addresses = geocoder.getFromLocation(LATITUDE,
LONGITUDE, 1);
if (addresses != null) {
returnedAddress = addresses.get(0);
// address details are retrived line by line
if (returnedAddress != null) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < returnedAddress
.getMaxAddressLineIndex(); i++) {
sb.append(returnedAddress.getAddressLine(i));
}
loc = sb.toString();
// Toast.makeText(getBaseContext(), "address is "+loc, Toast.LENGTH_SHORT).show();
logAddress = loc;
logLatitude = Double.toString(LATITUDE);
logLongtitude = Double.toString(LONGITUDE);
} else {
}
} else {
}
} catch (Exception e) {
e.printStackTrace();
}
return loc;
}
private void showGPSDisabledAlertToUser() {
AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
alertDialogBuilder.setMessage("GPS is disabled in your device. Would you like to enable it?")
.setCancelable(false)
.setPositiveButton("Goto Settings Page To Enable GPS",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
Intent callGPSSettingIntent = new Intent(
android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS);
startActivity(callGPSSettingIntent);
}
});
alertDialogBuilder.setNegativeButton("Cancel",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
}
});
AlertDialog alert = alertDialogBuilder.create();
alert.show();
}
}
任何帮助都表示赞赏.. !!
答案 0 :(得分：1)
尝试此操作以关闭应用程序：
quitBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View paramView)
{
finish();
moveTaskToBack(true);
}
});
答案 1 :(得分：1)
试试这个：
将此代码放在location为null的条件中。
new AlertDialog.Builder(context)
.setTitle("Close Application")
.setMessage("Do you want to close the Application?")
.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
finish();
}
})
.setNegativeButton("No", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// do nothing
}
})
.setIcon(android.R.drawable.ic_dialog_alert)
.show();