我正在尝试使用swift1.2中的AppConnectSDK访问MDM,但出现以下错误:[AppConnect:Error]AppConnectcannotbeinstantiateddirectly.Instead,call+initWithDelegate:andthen+sharedInstance.代码片段:importUIKit@UIApplicationMainclassAppDelegate:UIResponder,UIApplicationDelegate,AppConnectDelegate{varwindow:UIWindow?varappct=AppConnect