前言
API是個類似介面的東西,它提供一個窗口讓大家去做eBay的操作,這邊打個比方。

一個人去銀行(API)要選擇你要做什麼事情,去相關的櫃檯(窗口)去處理,櫃檯會詢問你要做什麼事情,並且驗證你的身分(Token),你只需要把你的需求(參數),還有要做什麼事情(呼叫哪個服務),他就會幫你去做操作,譬如你要查詢你的帳戶餘額,那麼可能需要驗證你的身分,他會跟你說(回傳)你餘額多少錢,API的概念差不多是這樣,不過這是指WEB APIs(網站應用程式)。
工具與環境
目前使用PHP&MySQL(WAMP)&PHP5_SimpleTrading來作開發。

申請eBay開發者帳號
申請網址：https://go.developer.ebay.com/

申請好後，登入進去，然後幫使用者申請帳號，
並且綁定開發者帳號綁定網址：http://sandbox.ebay.com/

會看到這個頁面

然後輸入eBay帳號密碼，如果第一次可能需要語音驗證，eBay那邊會用程式打電話過來，會唸一串數字記得記錄下來，才能來做綁定動作，並且獲取到Token。

實戰篇

Key.php 設定

<?php
    error_reporting(E_ALL);

    // these keys can be obtained by registering at http://developer.ebay.com
    
    $production         = TRUE;   // toggle to true if going against production
    $compatabilityLevel = 890;    // eBay API version
    
    if ($production) {
        $devID = 'my dev';   // these prod keys are different from sandbox keys
        $appID = 'my app';
        $certID = 'certID';
        //set the Server to use (Sandbox or Production)
        $serverUrl = 'https://api.ebay.com/ws/api.dll';      // server URL different for prod and sandbox
        //the token representing the eBay user to assign the call with
        $userToken = '';          
    } else {  
        // sandbox (test) environment
        $devID = 'DDD_SAND';         // insert your devID for sandbox
        $appID = 'AAA_SAND';   // different from prod keys
        $certID = 'CCC_SAND';  // need three 'keys' and one token
        //set the Server to use (Sandbox or Production)
        $serverUrl = 'https://api.sandbox.ebay.com/ws/api.dll';
        // the token representing the eBay user to assign the call with
        // this token is a long string - don't insert new lines - different from prod token
        $userToken = 'SANDBOX_TOKEN';                 
    }        
?>

範例一（取得ebay時間）

<?php

require_once('keys.php');
require_once('eBaySession.php');

//SiteID must also be set in the Request's XML
//SiteID = 0  (US) - UK = 3, Canada = 2, Australia = 15, ....
//SiteID Indicates the eBay site to associate the call with

$siteID = 0;

//the call being made:
$verb = 'GeteBayOfficialTime';
//Level / amount of data for the call to return (default = 0)
$detailLevel = 0;


///Build the request Xml string
$requestXmlBody = <<<XML
<?xml version="1.0" encoding="utf-8" ?>
<GeteBayOfficialTimeRequest xmlns="urn:ebay:apis:eBLBaseComponents">
<RequesterCredentials>
<eBayAuthToken>$userToken</eBayAuthToken>
</RequesterCredentials> 
</GeteBayOfficialTimeRequest>
XML;

//Create a new eBay session with all details pulled in from included keys.php
$session = new eBaySession($userToken, $devID, $appID, $certID, $serverUrl, $compatabilityLevel, $siteID, $verb);

//send the request and get response
$responseXml = $session->sendHttpRequest($requestXmlBody);
if (stristr($responseXml, 'HTTP 404') || $responseXml == ''):
    die('<P>Error sending request');
endif;

$xml = simplexml_load_string($responseXml);
$json = json_encode($xml);
$array = json_decode($json, TRUE);
var_dump($array);

結語
多參考一下官方的範例去寫，最主要要了解參數的意義，還有就是獲取回傳的值，把資料放入到自己的資料庫，在去做篩選動作，或者去做其他操作，多嘗試多看文件，預祝大家系統成功！

參考資料
eBay api文件
http://developer.ebay.com/Devzone/xml/docs/Reference/ebay/index.html

作者資料
暱稱：蒼鴻、老鷹、eagle
QQ號 : 1486394478
Skype : chingfeng18@hotmail.com
Mail:
chingfeng18@hotmail.com
chingfeng18@gmail.com