如何用php API解决try and catch flutter错误？

Question

当我使用try和catch来使用API插入操作并且操作插入成功时，但不幸的是toast消息没有打印“注册成功”，它打印的是：

"Error:  ClientException: XMLHttpRequest error., uri="http://localhost/dashboard/help_me/signup.php"

  Future<void> SignupClient() async {
    if (name.text!= "" || phone.text!= "") {
      try {

        var res = await http.post(
          Uri.parse(ApisConnect.signupApi),
          body: 
          {
            "name": name.text,
            "phone": phone.text,
          }
        );

        var response = jsonDecode(res.body);

        if (response["success"] == true) {
          Fluttertoast.showToast(msg: 'signed up successfully');
        } else if (response["success"] == false) {
          Fluttertoast.showToast(msg: 'try again');
        }


      } catch (e) {
        Fluttertoast.showToast(msg: 'Error $e');
      }
    }
  }

我尝试删除 try and catch 或更改它。

Answer 1

您遇到的问题可能是由于 CORS（跨源资源共享）错误造成的。试试这个：

1-将响应正文和标头打印到终端。这将帮助您了解服务器返回的内容以及是否存在必要的 CORS 标头。

2-确保服务器的响应包含必要的 CORS 标头。服务器应通过包含标头来允许来自应用程序来源的请求。您必须在 API Gateway 中启用 CORS，如下所示：

<?php
// Allow from any origin
header("Access-Control-Allow-Origin: *"); //add this line for your flutter app would probably work.

// Allow specific HTTP methods
header("Access-Control-Allow-Methods: GET, POST, PUT, DELETE, OPTIONS");

// Allow specific headers
header("Access-Control-Allow-Headers: Content-Type, Authorization, X-Requested-With");

// Handle preflight requests
if ($_SERVER['REQUEST_METHOD'] == 'OPTIONS') {
    // Indicate allowed methods and headers
    header("Access-Control-Allow-Methods: GET, POST, PUT, DELETE, OPTIONS");
    header("Access-Control-Allow-Headers: Content-Type, Authorization, X-Requested-With");
    exit(0);
...

3-也请查看以下问题：IN Flutter Web getting 'XMLHttpRequest' error while Making HTTP call 以及这个 API Gateway CORS: no 'Access-Control-Allow-Origin' header