当将东西添加到NSPasteboard时收到通知
在我的应用程序中，我想收到通知如果有东西添加到NSPasteboard。如果我从任何其他程序复制文本，我希望我的应用程序知道它。
In my application I want to get notified if something is added into the NSPasteboard. If I copy an text from any other program I want my application to know about it.
在某个地方我读不能这样做。我应该创建一个计时器，并自己检查NSPasteboard的内容。
Somewhere I read it can't be done that way. I should create a timer and check the content of the NSPasteboard myself.
这是要做的方法吗？
是的，您必须轮询粘贴板以查看其内容是否已更改。这不是理想，但它是可能的。基本上，您有一个计时器，每秒触发一次或两次，并检查 - [NSPasteboard changeCount] 。如果 changeCount 更改，这意味着粘贴板的内容也已更改（或至少有一个新的所有者）。
Yes, you essentially have to poll the pasteboard to see if its contents have changed. It's not ideal, but it's possible. Basically, you have a timer that fires once or twice a second and checks the -[NSPasteboard changeCount]. If the changeCount changes, that means the contents of the pasteboard have also changed (or there's at least a new owner).