啥也不说，直接上代码。

我这里是post请求。

$url = "http://www.wd1x.com";
//headers数组内的格式
$headers = array();
$headers[] = "app-id:xxxxx";
$headers[] = "Content-Type:application/json";
$body   = array(
            "username" => "username",
            "password" => "password"
       );
$postBody    = json_encode($body);
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, $url);
curl_setopt($curl, CURLOPT_POST, true);
curl_setopt($curl, CURLOPT_HTTPHEADER, $headers);//设置请求头
curl_setopt($curl, CURLOPT_POSTFIELDS, $postBody);//设置请求体
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($curl, CURLOPT_CUSTOMREQUEST, 'POST');//使用一个自定义的请求信息来代替"GET"或"HEAD"作为HTTP请求。(这个加不加没啥影响)
$data = curl_exec($curl);
echo $data;