尝试实现 MIDIReceived 但我不知道结果发送到哪里
我想在 Objective C 程序中实现 MIDIReceived：
extern OSStatus MIDIReceived(MIDIEndpointRef src,const MIDIPacketList *pktlist);
一旦发送了 src 和 pktlist 变量，我应该将代码放在哪里？
我一直在尝试阅读代码的 extern OSStatus 部分，但我找不到任何内容。任何朝着正确方向前进的障碍将不胜感激。
I would like to implement MIDIReceived in a Objective C Program:
extern OSStatus MIDIReceived(MIDIEndpointRef src,const MIDIPacketList *pktlist);
Where would I put the code to utilize the src and pktlist variables once they are sent?
I've been trying to read about the extern OSStatus part of the code but I havn't been able to find anything. Any bumps in the right direction would be greatly appreciated.
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extern声明只是向编译器暗示某处存在具有该定义的函数。您可以将该代码放在其他任何地方，但它至少必须位于某个地方，否则您将在构建过程中收到链接器错误。有关更多信息，我建议阅读以下内容：
至于
OSStatus，这只是 OSX 上的返回代码。The
externdeclaration just hints to the compiler that there exists somewhere a function with that definition. You can put that code anywhere else, but it at least has to be somewhere or else you'll get a linker error during building.For more information, I suggest reading up on the following:
As for
OSStatus, that's just a return code on OSX.