使用[self方法]或@selector（方法）？

问题描述

任何人都可以告诉我下面两个语句之间的区别。

Can anyone enlighten me as to the differences between the two statements below.

[self playButtonSound];

AND：

[self performSelector:@selector(playButtonSound)];

我只是问我，因为我有一些旧的代码使用 @selector ，现在有了更多的知识，我不能想到为什么我没有使用 [self playButtonSound] 相反，他们似乎都做同样的这里写的。

I am just asking as I had some old code that used @selector, now with a little more knowledge I can't think why I did not use [self playButtonSound] instead, they both seem to do the same as written here.

gary

推荐答案

但是 [self playButtonSound]; 绝对是调用Objective-C中的方法的正常方法。但是，使用 performSelector：可以调用只在运行时确定的方法。

Both to the same thing, but [self playButtonSound]; is definitely the normal way to invoke a method in Objective-C. However, using performSelector: allows you to call a method that is only determined at runtime.

href =http://developer.apple.com/mac/library/documentation/cocoa/Reference/Foundation/Protocols/NSObject_Protocol/Reference/NSObject.html#//apple_ref/occ/intfm/NSObject/performSelector： = nofollow noreferrer> NSObject协议参考：

From the NSObject Protocol Reference:

id myClone = [anObject copy];
id myClone = [anObject performSelector:@selector(copy)];
id myClone = [anObject performSelector:sel_getUid("copy")];

但是， performSelector： $ b允许您发送
在运行时之前未确定的消息。 A
变量选择器可以作为
参数传递：

However, the performSelector: method allows you to send messages that aren’t determined until runtime. A variable selector can be passed as the argument:

SEL myMethod = findTheAppropriateSelectorForTheCurrentSituation();
[anObject performSelector:myMethod];

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