本文实例讲述了PHP实现货币换算的方法。分享给大家供大家参考。

具体实现代码如下：

/*

* File: CurrencyConverter.php

* Author: Simon Jarvis

* Copyright: 2005 Simon Jarvis

* Date: 10/12/05

* Link: http://www.white-hat-web-design.co.uk/articles/php-currency-conversion.php

*

* This program is free software; you can redistribute it and/or

* modify it under the terms of the GNU General Public License

* as published by the Free Software Foundation; either version 2

* of the License, or (at your option) any later version.

*

* This program is distributed in the hope that it will be useful,

* but WITHOUT ANY WARRANTY; without even the implied warranty of

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

* GNU General Public License for more details:

* http://www.gnu.org/licenses/gpl.html

*

*/

class CurrencyConverter {

var $xml_file = "www.ecb.int/stats/eurofxref/eurofxref-daily.xml";

var $mysql_host, $mysql_user, $mysql_pass, $mysql_db, $mysql_table;

var $exchange_rates = array();

//Load Currency Rates

function CurrencyConverter($host,$user,$pass,$db,$tb) {

$this->mysql_host = $host;

$this->mysql_user = $user;

$this->mysql_pass = $pass;

$this->mysql_db = $db;

$this->mysql_table = $tb;

$this->checkLastUpdated();

$conn = mysql_connect($this->mysql_host,$this->mysql_user,$this->mysql_pass);

$rs = mysql_select_db($this->mysql_db,$conn);

$sql = "SELECT * FROM ".$this->mysql_table;

$rs =  mysql_query($sql,$conn);

while($row = mysql_fetch_array($rs)) {

$this->exchange_rates[$row['currency']] = $row['rate'];

}

}

/* Perform the actual conversion, defaults to £1.00 GBP to USD */

function convert($amount=1,$from="GBP",$to="USD",$decimals=2) {

return(number_format(($amount/$this->exchange_rates[$from])*$this->exchange_rates[$to],$decimals));

}

/* Check to see how long since the data was last updated */

function checkLastUpdated() {

$conn = mysql_connect($this->mysql_host,$this->mysql_user,$this->mysql_pass);

$rs = mysql_select_db($this->mysql_db,$conn);

$sql = "SHOW TABLE STATUS FROM ".$this->mysql_db." LIKE '".$this->mysql_table."'";

$rs =  mysql_query($sql,$conn);

if(mysql_num_rows($rs) == 0 ) {

$this->createTable();

} else {

$row = mysql_fetch_array($rs);

if(time() > (strtotime($row["Update_time"])+(12*60*60)) ) {

$this->downloadExchangeRates();

}

}

}

/* Download xml file, extract exchange rates and store values in database */

function downloadExchangeRates() {

$currency_domain = substr($this->xml_file,0,strpos($this->xml_file,"/"));

$currency_file = substr($this->xml_file,strpos($this->xml_file,"/"));

$fp = @fsockopen($currency_domain, 80, $errno, $errstr, 10);

if($fp) {

$out = "GET ".$currency_file." HTTP/1.1rn";

$out .= "Host: ".$currency_domain."rn";

$out .= "User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8) Gecko/20051111 Firefox/1.5rn";

$out .= "Connection: Closernrn";

fwrite($fp, $out);

while (!feof($fp)) {

$buffer .= fgets($fp, 128);

}

fclose($fp);

$pattern = "{}is";

preg_match_all($pattern,$buffer,$xml_rates);

array_shift($xml_rates);

for($i=0;$i

$exchange_rate[$xml_rates[0][$i]] = $xml_rates[1][$i];

}

$conn = mysql_connect($this->mysql_host,$this->mysql_user,$this->mysql_pass);

$rs = mysql_select_db($this->mysql_db,$conn);

foreach($exchange_rate as $currency=>$rate) {

if((is_numeric($rate)) && ($rate != 0)) {

$sql = "SELECT * FROM ".$this->mysql_table." WHERE currency='".$currency."'";

$rs =  mysql_query($sql,$conn) or die(mysql_error());

if(mysql_num_rows($rs) > 0) {

$sql = "UPDATE ".$this->mysql_table." SET rate=".$rate." WHERE currency='".$currency."'";

} else {

$sql = "INSERT INTO ".$this->mysql_table." VALUES('".$currency."',".$rate.")";

}

$rs =  mysql_query($sql,$conn) or die(mysql_error());

}

}

}

}

/* Create the currency exchange table */

function createTable() {

$conn = mysql_connect($this->mysql_host,$this->mysql_user,$this->mysql_pass);

$rs = mysql_select_db($this->mysql_db,$conn);

$sql = "CREATE TABLE ".$this->mysql_table." ( currency char(3) NOT NULL default '', rate float NOT NULL default '0', PRIMARY KEY(currency) ) ENGINE=MyISAM";

$rs =  mysql_query($sql,$conn) or die(mysql_error());

$sql = "INSERT INTO ".$this->mysql_table." VALUES('EUR',1)";

$rs =  mysql_query($sql,$conn) or die(mysql_error());

$this->downloadExchangeRates();

}

}

?>

上面的代码复制到一个新文件并将其保存为CurrencyConverter.php。当你需要转换包含类文件,称为“转换”功能。你需要输入自己的mysql数据库变量如登录详细信息。下面的例子将￡2.50英镑转换成美元(美元)。

include('CurrencyConverter.php');

$x = new CurrencyConverter('your_host','your_username','your_password','your_database_name','your_table_name');

echo $x->convert(2.50,'GBP','USD');

?>

希望本文所述对大家的php程序设计有所帮助。