当我用postman测试php代码时，我得到的答案是“success”。但是当我们用flutter测试时，代码没有进入if结构或else结构，打印不起作用。我尝试不使用json_encode，但它仍然不起作用。当我用Dio测试时，我再次看到同样的无响应。我该怎么办？

import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;

import 'login.dart';

abstract class LoginViewModel extends State<Login> {
  final TextEditingController email_controller = TextEditingController();
  final TextEditingController pass_controller = TextEditingController();
  Future<void> fetchLogin() async {
    try {
      final response = await http.post(Uri.parse("http://********/canlidestek/login.php"),
          body: {"email": email_controller.text, "password": pass_controller.text});

      if (response.statusCode == 200) {
        var data = json.decode(response.body);
        print(data);
      }
    } catch (e) {
      print(e);
    }
  }
}

PHP语言

<?php 
    session_start();
    include_once "config.php";
    if($_POST){
        $email = $_POST['email'];
    $password = $_POST['password'];
    if(!empty($email) && !empty($password)){
        $sql = mysqli_query($conn, "SELECT * FROM livesup WHERE email = '{$email}'");
        if(mysqli_num_rows($sql) > 0){
            $row = mysqli_fetch_assoc($sql);
    
                $status = "Online";
                $sql2 = mysqli_query($conn, "UPDATE livesup SET status = '{$status}' WHERE unique_id = {$row['unique_id']}");
                if($sql2){
                    $_SESSION['unique_id'] = $row['unique_id'];
                    echo json_encode("success");
                }else{
                    echo "Something went wrong. Please try again!";
                }
        
        }else{
            echo "$email - This email not Exist!";
        }
    }else{
        echo "All input fields are required!";
    }
    }else
    {
            echo "no data post";

    }
?>