PHP - 在键/值对中拆分字符串

array(
  "key" => "value",
  "key2" => "value2"
)

$parts = explode(",", $string)
$parts = array_map("trim", $parts);
foreach($parts as $currentPart)
{
    list($key, $value) = explode("=", $currentPart);
    $keyValues[$key] = $value;
}

$str = "key=value, key2=value2";
preg_match_all("/([^,= ]+)=([^,= ]+)/", $str, $r); 
$result = array_combine($r[1], $r[2]);
var_dump($result);