NSObject中的performSelector用法简介

- (id)performSelector:(SEL)aSelector

Description

[说明]

Sends a specified message to the receiver and returns the result of the message. (required)

[发送指定消息的接收和返回消息的结果。（必填)]

 

The performSelector: method is equivalent to sending an aSelector message directly to the receiver. For example, all three of the following messages do the same thing:

[该performSelector：方法等效于直接发送aSelector消息发送到接收器。举例来说，所有这三个以下消息做同样的事情：]

 

id myClone = [anObject copy];

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

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

 

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

[然而，performSelector：方法允许你发送那些没有确定，直到运行时的消息。变量选择器可作为参数传递：]

 

SEL myMethod = findTheAppropriateSelectorForTheCurrentSituation(); 

[anObject performSelector:myMethod];

 

The aSelector argument should identify a method that takes no arguments. For methods that return anything other than an object, use NSInvocation.

[该aSelector参数应该找出一种方法，它没有参数。对于返回以外的任何一个对象的方法，使用NSInvocation。]

Parameters

[参数]

aSelector

A selector identifying the message to send. If aSelector is NULL, an NSInvalidArgumentException is raised. [选择器确定要发送的消息。如果aSelector为NULL，一个NSInvalidArgumentException提高。]

Returns

[返回]

An object that is the result of the message.

[一个对象，该对象是消息的结果。]

Availability

[可用性]

OS X (10.0 and later)

[OS X 10.0及更高版本]

Declared In

[宣称]

NSObject.h

Reference

[参考]

NSObject Protocol Reference

[参考NSObject协议]