Questions:
When I press the button(named “current location”) it should shows current location(lat & long) on the textview(named “tvAddress”) .But it’s not working as I expect. It’s giving me errors.Errors are given below.Can anyone help me plz
Error is :
02-05 23:37:22.429: E/AndroidRuntime(20293): FATAL EXCEPTION: main
02-05 23:37:22.429: E/AndroidRuntime(20293): java.lang.IllegalStateException: Could not execute method of the activity
02-05 23:37:22.429: E/AndroidRuntime(20293): at android.view.View$1.onClick(View.java:3680)
02-05 23:37:22.429: E/AndroidRuntime(20293): at android.view.View.performClick(View.java:4191)
02-05 23:37:22.429: E/AndroidRuntime(20293): at android.view.View$PerformClick.run(View.java:17229)
02-05 23:37:22.429: E/AndroidRuntime(20293): at android.os.Handler.handleCallback(Handler.java:615)
02-05 23:37:22.429: E/AndroidRuntime(20293): at android.os.Handler.dispatchMessage(Handler.java:92)
02-05 23:37:22.429: E/AndroidRuntime(20293): at android.os.Looper.loop(Looper.java:137)
02-05 23:37:22.429: E/AndroidRuntime(20293): at android.app.ActivityThread.main(ActivityThread.java:4960)
02-05 23:37:22.429: E/AndroidRuntime(20293): at java.lang.reflect.Method.invokeNative(Native Method)
02-05 23:37:22.429: E/AndroidRuntime(20293): at java.lang.reflect.Method.invoke(Method.java:511)
02-05 23:37:22.429: E/AndroidRuntime(20293): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038)
02-05 23:37:22.429: E/AndroidRuntime(20293): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805)
02-05 23:37:22.429: E/AndroidRuntime(20293): at dalvik.system.NativeStart.main(Native Method)
02-05 23:37:22.429: E/AndroidRuntime(20293): Caused by: java.lang.reflect.InvocationTargetException
02-05 23:37:22.429: E/AndroidRuntime(20293): at java.lang.reflect.Method.invokeNative(Native Method)
02-05 23:37:22.429: E/AndroidRuntime(20293): at java.lang.reflect.Method.invoke(Method.java:511)
02-05 23:37:22.429: E/AndroidRuntime(20293): at android.view.View$1.onClick(View.java:3675)
02-05 23:37:22.429: E/AndroidRuntime(20293): ... 11 more
02-05 23:37:22.429: E/AndroidRuntime(20293): Caused by: java.lang.NullPointerException
02-05 23:37:22.429: E/AndroidRuntime(20293): at com.mamun.tasktest.MapActivity.marker(MapActivity.java:129)
02-05 23:37:22.429: E/AndroidRuntime(20293): ... 14 more
MapActivity.java
package com.mamun.tasktest;
import java.io.IOException;
import java.util.ArrayList;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.Address;
import android.location.Geocoder;
import android.location.Location;
import android.location.LocationManager;
import android.os.Bundle;
import android.provider.Settings;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesClient;
import com.google.android.gms.location.LocationClient;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.MapFragment;
import com.google.android.gms.maps.GoogleMap.OnMarkerDragListener;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
public class MapActivity extends Activity implements GooglePlayServicesClient.ConnectionCallbacks, GooglePlayServicesClient.OnConnectionFailedListener, LocationListener {
private LocationManager manager;
private TextView tvAddress;
private Button btncurrent;
private LocationClient locationClient;
private GoogleMap googleMap;
private MapFragment mapFragment;
@Override
protected void onCreate(Bundle savedInstanceState) {
manager = (LocationManager) getSystemService(LOCATION_SERVICE);
tvAddress = (TextView) findViewById(R.id.tvaddress);
btncurrent= (Button)findViewById(R.id.btncurrent
super.onCreate(savedInstanceState);
setContentView(R.layout.map);
locationClient = new LocationClient(this, this, this);
}
public void marker(View v) {
Location currentLocation = locationClient.getLastLocation();
tvAddress.setText(currentLocation.getLatitude()+" , "+ currentLocation.getLongitude());
Geocoder geocoder = new Geocoder(this);
try {
ArrayList<Address> addresses = (ArrayList<Address>) geocoder.getFromLocation(currentLocation.getLatitude(), currentLocation.getLongitude(), 5);
Address addr = addresses.get(0);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
@Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();
locationClient.connect();
}
@Override
protected void onPause() {
// TODO Auto-generated method stub
super.onPause();
locationClient.disconnect();
}
@Override
public void onLocationChanged(Location location) {
// TODO Auto-generated method stub
}
@Override
public void onConnectionFailed(ConnectionResult result) {
// TODO Auto-generated method stub
}
@Override
public void onConnected(Bundle connectionHint) {
}
@Override
public void onDisconnected() {
// TODO Auto-generated method stub
}
}
map.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical" >
<EditText
android:id="@+id/etSearch"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10"
android:hint="Search your location" >
<requestFocus />
</EditText>
<TextView
android:id="@+id/tvaddress"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<Button
android:id="@+id/btncurrent"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="marker"
android:text="Current Location"
android:layout_marginLeft="98dp" />
<Button
android:id="@+id/btnsave"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Save" />
</LinearLayout>
</LinearLayout>
<FrameLayout
android:id="@+id/map_container"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<fragment
android:id="@+id/maps"
android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.google.android.gms.maps.MapFragment" />
</FrameLayout>
</LinearLayout>
How to&Answers:
You are calling findViewById before setting the View, so when you call tvAddress.setText, tvAddress is null. Start with this code instead :
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.map);
manager = (LocationManager) getSystemService(LOCATION_SERVICE);
tvAddress = (TextView) findViewById(R.id.tvaddress);
btncurrent= (Button)findViewById(R.id.btncurrent);
locationClient = new LocationClient(this, this, this);
}
Also, you got the error wrong, the real cause is this :
Caused by: java.lang.NullPointerException
at com.mamun.tasktest.MapActivity.marker(MapActivity.java:129)
Take your time to read the stack trace carefully and look for places where it points to classes you wrote, it is always a good place to start for investigating bugs 😉
Answer：
Your first two lines in onCreate method should be these ones:
super.onCreate(savedInstanceState);
setContentView(R.layout.map);
Answer：
Just you have wrongly initialized your views. As you can only access the views after setContentView() method and you have done that totally reverse that is why its throwing error.
Just change your onCreate() as below:
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.map);
manager = (LocationManager) getSystemService(LOCATION_SERVICE);
tvAddress = (TextView) findViewById(R.id.tvaddress);
btncurrent= (Button)findViewById(R.id.btncurrent);
