Android Check GPS State On and Off condition useing Toggle Button?

MainActivity.java

public class MainActivity extends Activity {

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

final ToggleButton tB = (ToggleButton) findViewById(R.id.toggleButton);

tB.setOnClickListener(new OnClickListener() {

@Override

public void onClick(View arg0) {

if (tB.isChecked()) {

// Button is ON

Log.i("", "true");

Intent intent = new Intent(

"android.location.GPS_ENABLED_CHANGE");

intent.putExtra("enabled", true);

sendBroadcast(intent);

String provider = Settings.Secure.getString(

getContentResolver(),

Settings.Secure.LOCATION_PROVIDERS_ALLOWED);

if (!provider.contains("gps")) { // if gps is disabled

final Intent poke = new Intent();

poke.setClassName("com.android.settings",

"com.android.settings.widget.SettingsAppWidgetProvider");

poke.addCategory(Intent.CATEGORY_ALTERNATIVE);

poke.setData(Uri.parse("3"));

sendBroadcast(poke);

}

} else {

// Button is OFF

Log.i("", "false");

String provider = Settings.Secure.getString(

getContentResolver(),

Settings.Secure.LOCATION_PROVIDERS_ALLOWED);

if (provider.contains("gps")) { // if gps is enabled

final Intent poke = new Intent();

poke.setClassName("com.android.settings",

"com.android.settings.widget.SettingsAppWidgetProvider");

poke.addCategory(Intent.CATEGORY_ALTERNATIVE);

poke.setData(Uri.parse("3"));

sendBroadcast(poke);

}

}

}

});

}

}

activity.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent" >

    <LinearLayout

        android:id="@+id/toggleButton1"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:orientation="horizontal" >

        <ToggleButton

            android:id="@+id/toggleButton"

            android:layout_width="fill_parent"

            android:layout_height="wrap_content"

            android:layout_marginLeft="50dp"

            android:layout_marginRight="50dp"

            android:layout_marginTop="50dp"

            android:text="ToggleButton" />

    </LinearLayout>

</RelativeLayout>

and give permissions to in  `Androidmanifest.xml ` like this 

      <uses-permission android:name="android.permission.INTERNET" />

    <uses-permission android:name="android.permission.WRITE_SETTINGS" />    

    <uses-permission android:name="android.permission.CHANGE_NETWORK_STATE"/>