Dart HttpOverrides用法及代碼示例

此類有助於使用模擬實現覆蓋HttpClient。它應該由客戶端代碼中的另一個類擴展，並具有構建模擬實現的覆蓋。此基類中的實現默認為實際的HttpClient 實現。例如：

// An implementation of the HttpClient interface
class MyHttpClient implements HttpClient {
  MyHttpClient(SecurityContext? c);

  @override
  noSuchMethod(Invocation invocation) {
    // your implementation here
  }
}

void main() {
  HttpOverrides.runZoned(() {
    // Operations will use MyHttpClient instead of the real HttpClient
    // implementation whenever HttpClient is used.
  }, createHttpClient: (SecurityContext? c) => MyHttpClient(c));
}