rest - 如何在 Flutter 网络调用中添加动态 HTTP header

Question

我必须从登录 API 响应中获取“cookie” header 并将其用于其他 API。

我能够从 http.Response 获取 header 值

像这样

var cookie = loginResponsehttp.headers.keys.firstWhere(
    (k) => loginResponsehttp.headers[k] == 'cookie',
    orElse: () => null);

但现在我想在未来的 API 调用中动态添加此 header 值。 (将在登录后调用 API)

Answer 1

只需创建一个带有自定义方法的 API 类即可执行请求并将 cookie 存储在类中。

基本实现(改编自工作代码，删除和简化的内容):

class MyApi {

  String myCookie;

  Future<bool> loginUser({@required String username, @required String password}) {

    // THIS must be the return point, because we are returning a future!!!
    return this.apiRequest(method: 'post', url: 'http://example.com/api/login', params: {'user': username, 'password':password})
    .then( (response) {
        if (response.statusCode == 200) {

            // GET THE COOKIE HERE
            myCookie = response.headers.keys.firstWhere((k) => loginResponsehttp.headers[k] == 'cookie', orElse: () => null);
        }
    }

  Future<http.Response> apiRequest({
    @required String url,
    dynamic params}) async {

      // separate in to get an all
      if(method == 'get') {
        return http.get(url, headers: {'X-Auth': myCookie, 'Content-Type': 'application/json'});
      } else if (method == 'post') {
        return http.post(url, body: json.encode(params), headers: {'X-Auth': myCookie, "Content-Type": 'application/json'});
      } else {
        // ERROR!!! throw exception?
        throw Exception('Unknown http method: ' + method);
      }
    }
 }