POST提取请求-转换为JSON

Question

我正在尝试从React前端向php文件发出发布请求。

handleFormSubmit(event) {
  event.preventDefault()
  let payload = this.state.email;
  fetch(`http://website.com/file.php`, {
    credentials: 'same-origin',
    method: 'POST',
    mode: 'cors',
    headers:{
      'Access-Control-Allow-Origin':'*'
      },
    body: payload
  })
  .then((response) => response.json() )
  .then((body) => {
    console.log(body);
    this.setState({
      email: body,
      message: 'Success!'
    });
  });
}

我收到一条错误消息，而不是通过获取请求。

Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin '...' is therefore not allowed access. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

Answer 1

看起来您的服务器不包含响应预检请求（OPTIONS）的Access-Control-Allow-Origin标头。 如果缺少Access-Control-Allow-Origin，则CORS请求将失败。

以下是一些很棒的文章，它们解释了CORS的工作原理：

https://www.html5rocks.com/zh-CN/tutorials/cors/

https://developer.mozilla.org/zh-CN/docs/Web/HTTP/Access_control_CORS

希望这可以帮助！