地理位置显示不同的城市不是很准确

Question

I'm using geolocation to detect current city which is not showing the exact city, for example i am in Bangalore and it shows Chennai or sometimes Thiruvanantpuram. Please let me know how to make it accurate to show current city. Below is my code -

function fetch($host) {

    if ( function_exists('curl_init') ) {

        //use cURL to fetch data
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $host);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_USERAGENT, 'geoPlugin PHP Class v1.1');
        $response = curl_exec($ch);
        curl_close ($ch);

    } else if ( ini_get('allow_url_fopen') ) {

        //fall back to fopen()
        $response = file_get_contents($host, 'r');

    } else {

        trigger_error ('geoPlugin class Error: Cannot retrieve data. Either compile PHP with cURL support or enable allow_url_fopen in php.ini ', E_USER_ERROR);
        return;

    }

    return $response;
}

function convert($amount, $float=2, $symbol=true) {

    //easily convert amounts to geolocated currency.
    if ( !is_numeric($this->currencyConverter) || $this->currencyConverter == 0 ) {
        trigger_error('geoPlugin class Notice: currencyConverter has no value.', E_USER_NOTICE);
        return $amount;
    }
    if ( !is_numeric($amount) ) {
        trigger_error ('geoPlugin class Warning: The amount passed to geoPlugin::convert is not numeric.', E_USER_WARNING);
        return $amount;
    }
    if ( $symbol === true ) {
        return $this->currencySymbol . round( ($amount * $this->currencyConverter), $float );
    } else {
        return round( ($amount * $this->currencyConverter), $float );
    }
}

Answer 1

The issue is not with your code but the source of information. IP geolocation is not 100% accurate and you need to live with it. The best remedy is to use a service such as Ipregistry (disclaimer: I run the service) that correlates data from multiple sources in order to reduce false positives and mitigate what you experience.

Based on your code, it looks like you are guessing your users' currency. In that case, you could perform an HTTP get to the following endpoint:

https://api.ipregistry.co/?key=tryout

and look at the response field currency.