mysql的android fetch图像导致app冻结

Question

我做了一个学校项目，我在网上将图像作为blob插入到MySQL中，我将该图像提取到Android应用程序，然后在用ImageView解码后将图像设置为base64，问题是这个过程导致应用程序冻结并需要很长时间才能在Android中显示它，有时手机响应超过两分钟，我不知道该怎么做，我的代码中没有任何错误{ {1}}也不在PHP。请帮助我并告诉我我能做些什么，以更快更有效地显示这个图像。谢谢

php代码：

Java android

访问以上功能：

  ...
 public function StudentsOfParent($mobile){

 $stmt = $this->conn->prepare("SELECT
                         a.id,
                         a.name, 
                         a.mobile, 
                         c.id as sutdentId, 
                         c.user_id, 
                         c.full_name, 
                         c.school, 
                         c.level,
                         c.year,
                         c.photo,
                         d.id as busId,                   
                         d.bus_name as plate_no,
                         e.id as DriverId,                           
                         e.driverphone_number,                          
                         e.driver_fullname                          
                         from users a 
                         join students c 
                         on a.id = c.user_id
                         join buses d 
                         on c.id = d.student_id
                         join drivers e
                         on e.id = d.driver_id where a.mobile= ?");

    $stmt->bind_param("i", $mobile);
if ($stmt->execute()) {    
   $result = $stmt->get_result();
   $usersArr = $result->fetch_all(MYSQLI_ASSOC);
   $stmt->close();
   $result->free(); //Because why not?
   return array_map(function ($user) {
         $user['photo'] = base64_encode($user['photo']);
         return $user;
  }, $usersArr);
 } else {
       return NULL; 
 }
  ...

用于将图片传输到界面的Android代码：

          ....
       if (isset($_POST['mobile'])){

    $mobile = $_POST['mobile'];

    $usersArr = $db->StudentsOfParent($mobile);
    if ($usersArr != false) { 

      $response["error"]= FALSE;

      $response["user"] = $usersArr;
    echo json_encode($response); 

      .....