为什么当我单击按钮时此应用程序崩溃了？ 那是什么problam？ 我在主要活动中只有一个按钮，当我单击该按钮时，它崩溃了！
package com.example.gpsapp;
import android.Manifest;
import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;
import android.provider.ContactsContract;
import android.provider.Settings;
import android.support.v4.app.ActivityCompat;
import android.support.annotation.Nullable;
public class GpsTracker extends Service implements LocationListener {
private Context context;
private LocationManager locationManager;
private Location location;
private double latitude = 0.0;
private double longitude = 0.0;
private boolean isGpsEnabled= false; // flagi baraye gps
private boolean isNetworkEnabled = false;//hamishe ke az ro gps nis az net ham mishe
private boolean canGetLocation = false; //neshan midahad aya object ma mitavanad location ra daryaft konad ya na
public static final int TIME_BW_UPDATE = 1000*60*1; // 1 minute
public static final int MIN_DISTANCE_FOR_UPDATE =10; // 10 METER
// tabee sazande ke context ro daryaft mikone
public GpsTracker(Context context){
this.context = context;
getLocation();
}
public Location getLocation() throws SecurityException {
locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);// daryafte location manage va set kardane anha
isGpsEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
isNetworkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGpsEnabled && !isNetworkEnabled) {
//no provider enabled
canGetLocation = false;
} else {
canGetLocation = true;
// first , get location by network provider
if (isNetworkEnabled) {
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, TIME_BW_UPDATE, MIN_DISTANCE_FOR_UPDATE, this);// bayad dar manifest mojavez dashte bashe
if (locationManager!= null){
location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location!= null){
latitude=location.getLatitude();
longitude =location.getLongitude();
}
}
}
if(isGpsEnabled && location == null){
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER , TIME_BW_UPDATE, MIN_DISTANCE_FOR_UPDATE , this);
if (locationManager !=null){
location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null){
latitude=location.getLatitude();
longitude =location.getLongitude();
}
}
}
}
return location;
}
public double getLatitude(){
if (location != null){
latitude = location.getLatitude();
}
return latitude;
}
public double getLongitude(){
if (location != null){
longitude = location.getLongitude();
}
return longitude;
}
public boolean canGetLocation (){ // aya mitavanad location ra begirad ya na agar natonest ye dialogi mide be karbar
return this.canGetLocation;
}
// zamani ke Gps roshan nist chikar konad
public void showGpsAlertDialog(){
AlertDialog.Builder builder = new AlertDialog.Builder(context);
builder.setTitle("GPS").setMessage("Gps is not Enabled . turn it ON")
.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent();
intent.setAction(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
context.startActivity(intent);
// dialog.dismiss();
}
})
.setNegativeButton("cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
builder.show();
}
public void stopUsingGps (){
if(locationManager != null){
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_DENIED &&
ActivityCompat.checkSelfPermission(this,Manifest.permission.ACCESS_COARSE_LOCATION)
==PackageManager.PERMISSION_GRANTED) {
locationManager.removeUpdates(this);
}
}
}
@Override
public void onLocationChanged(Location location) {
this.location = location;
getLatitude();
getLongitude();
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
@Nullable
@Override
public IBinder onBind(Intent intent) {
return null;
}
}
这是我单击时因以下错误而崩溃的错误代码：
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.gpsapp, PID: 30374
java.lang.IllegalStateException: Could not execute method for android:onClick
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:390)
at android.view.View.performClick(View.java:6261)
at android.widget.TextView.performClick(TextView.java:11163)
at android.view.View$PerformClick.run(View.java:23748)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6776)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1496)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1386)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:385)
at android.view.View.performClick(View.java:6261)
at android.widget.TextView.performClick(TextView.java:11163)
at android.view.View$PerformClick.run(View.java:23748)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6776)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1496)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1386)
Caused by: java.lang.SecurityException: "network" location provider requires ACCESS_COARSE_LOCATION or ACCESS_FINE_LOCATION permission.:
MainActivity：
public class MainActivity extends AppCompatActivity {
TextView tv;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv= this.<TextView>findViewById(R.id.tv);
}
public void onClick(View view) {
// Toast.makeText(this, "hi sahar", Toast.LENGTH_SHORT).show();
GpsTracker gpsTracker = new GpsTracker(this);
if (gpsTracker.canGetLocation()){
double lat = gpsTracker.getLatitude();
double lon= gpsTracker.getLongitude();
tv.append("Your Location is - \nLat: " + lat+ "\nLong: " + lon);
// Toast.makeText(this, "Location is \n lat : " + lat + "\n lon : " +lon ,
Toast.LENGTH_SHORT).show();
}else {
gpsTracker.showGpsAlertDialog();
}
}