namespace app\admin\api;
class TestApi{
public function demo1(){
echo 333;
}
}
下面调用

use app\admin\api\TestApi;
class TestController{
public $test=null;
public $test1=null;
public $test2=null;

public function demo1(){
$this->test['b']=new TestApi();
$this->test2=new TestApi();
//代码执行正常
$this->test2->demo1();
//无法调用demo1()方法
$this->test['b']->demo1();

}
}