First Responder

Question

我是i-phone开发的新手，任何人都可以向我解释IB中的第一响应者。在IB中可以在哪里使用它？有什么用。

Answer 1

See this previous answer: The concept of file's owner,first responder, and application delegate in iPhone.

You can also search for "First responder" in SO. There was many subjects

Answer 2

Every nib file has atleast two files; File's Owner and First Responder which cannot be deleted. File's Owner simply shows that it owns the object in the nib file. First Responder tells us which object are we currently interacting with; like the textbox, buttons...