如何删除插槽，在Designer模式下创建？
问题描述：
我创建了 cancelButton 按钮。然后我创建了函数槽 on_cancelButton_clicked（）它使用上下文菜单项转到槽。但是，一段时间后，我删除了这个按钮（它不再需要），并试图删除该函数，但编译器给出错误未定义的引用< class_name> :: on_cancelButton_clicked（）
I've created the button cancelButton. Then I've created function-slot on_cancelButton_clicked() for it using context menu item Go to slot. But, after a while, I've deleted this button (it wasn't longer needed), and tried to delete that function, but compiler gives error undefined reference to <class_name>::on_cancelButton_clicked().
我已清除build文件夹（并删除了它），检查了ui文件中可以指向此函数的一些行，但我没有发现任何东西。
I've made cleanup of build folder (and removed it), checked for some lines in ui file that can point to this function, but i didn't found anything.