I would only use a custom header when there is no other way to pass information by standard or convention. Darren102 is explaining the typical way to pass that value. Your Api will be much more friendly by using typical patterns verse using custom headers.That's not to say you won't have a case to use them, just that they should be the last resort and something not already handled by the HTTP spec.
The URL indicates the resource itself. A "client" is a resource that can be acted upon, so should be part of the base url: /orders/view/client/23.
参数就是参数化对资源的访问。这尤其适用于文章和搜索: /orders/find?q=blahblah&sort=foo。参数和子资源之间有一条细微的界限: /orders/view/client/23/active versus /orders/view/client/23?show=active。我建议使用子资源样式和保留参数进行搜索。