在颤抖中，我使用了一个php文件，该文件从数据库查询返回了json响应，但是当我尝试解码json时，出现此错误：

E/flutter ( 8294): [ERROR:flutter/lib/ui/ui_dart_state.cc(148)] Unhandled
Exception: FormatException: Unexpected character (at character 1)
E/flutter ( 8294): [{"0":"PRUEBA","usu_nombre":"PRUEBA"}]
E/flutter ( 8294): ^

这是我的飞镖功能：

Future<String> iniciarSesion() async{
var usuario = textUsuario.text;
var password = textPassword.text;
var nombreUsuario;
var url ="http://192.168.1.37/usuario.php";

//Metodo post
var response = await http.post(
    url,
    headers:{ "Accept": "application/json" } ,
    body: { "usuario": '$usuario',"password": '$password'},
    encoding: Encoding.getByName("utf-8")
);
  List data = json.decode(response.body);
}

以及来自我的php文件的代码：

<?php
error_reporting(E_ALL);
ini_set('display_errors', '1');

include_once "Clases/conexion.php";

$usuario = $_POST['usuario'];
$password = $_POST['password'];

$consulta = "select usu_nombre
FROM usu_usuarios
WHERE usu_nusuario='$usuario'and usu_password='$password' and  usu_activo='SI'";

$mysql_obj = new Conectar();
$mysqli = $mysql_obj->crearConexion();

if($result = $mysqli->query($consulta)) {
if ($mysqli->affected_rows > 0) {
    while($row = $result->fetch_array()) {
        $myArray[] = $row;
    }
    header('Content-type: application/json');
    echo json_encode($myArray);
}else {
    header("HTTP/1.0 401 Datos Incorrectos");
    header('Content-type: application/json');
    $data = array("mensaje" => "Datos Incorrectos");
    echo json_encode($data);
}}
?>

我正在使用http dart依赖