您将 responseType: 'text' 放在了 httpOptions 的错误部分 - 它应该坐在headers的外面，像这样:

You've put responseType: 'text' in the wrong section of your httpOptions - It should sit outside of headers, like so:

private httpOptions = {
  headers: new HttpHeaders({
    'Accept': 'text/html, application/xhtml+xml, */*',
    'Content-Type': 'application/x-www-form-urlencoded'
  }),
  responseType: 'text'
};

根据您之前的情况，responseType 的请求标头被发送到服务器，而不是简单地向 Angular 发出指令以实际将响应视为文本.

With what you had before, a request header of responseType was being sent to the server, rather than simply having an instruction to Angular to actually treat the response as text.