我需要检查MFMessageComposeViewController
当前是否可见。我怎样才能做到这一点?
我现在正在做的是:
//Get the current visible view controller
ViewController *visible = ...
if([visible isKindOfClass:[MFMessageComposeViewController class]])
// This doesn't work because the class is actually CKSMSComposeController
而且我无法检查 CKSMSComposeController 然后 Xcode 会抱怨“使用未声明的标识符 'CKSMSComposeController'”