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NSObject中的performSelector用法简介

發布時間:2024/4/14 编程问答 33 豆豆
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-?(id)performSelector:(SEL)aSelector

Description

[說明]

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

[發送指定消息的接收和返回消息的結果。(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:

[該performSelector:方法等效于直接發送aSelector消息發送到接收器。舉例來說,所有這三個以下消息做同樣的事情:]

?

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:方法允許你發送那些沒有確定,直到運行時的消息。變量選擇器可作為參數傳遞:]

?

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.

[該aSelector參數應該找出一種方法,它沒有參數。對于返回以外的任何一個對象的方法,使用NSInvocation。]

Parameters

[參數]

aSelector

A selector identifying the message to send. If aSelector is NULL, an NSInvalidArgumentException is raised.

[選擇器確定要發送的消息。如果aSelector為NULL,一個NSInvalidArgumentException提高。]

Returns

[返回]

An object that is the result of the message.

[一個對象,該對象是消息的結果。]

Availability

[可用性]

OS X (10.0 and later)

[OS X 10.0及更高版本]

Declared In

[宣稱]

NSObject.h

Reference

[參考]

NSObject Protocol Reference

[參考NSObject協議]

轉載于:https://www.cnblogs.com/iOSCain/p/4015488.html

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