iOS移除屏幕的系统弹框

系统弹框在keyWindow中的class是 _UIAlertControllerShimPresenterWindow

UIWindow* keyWindow = [[UIApplication sharedApplication] keyWindow]；
NSString *windowDescription = NSStringFromClass([keyWindow class]);
        if ([windowDescription isEqualToString:@"_UIAlertControllerShimPresenterWindow"]){
            keyWindow.hidden = YES;
        }