objective-c - @selector - 有多个参数？

Question

我今天第一次使用 @selector，但一直无法弄清楚如何执行以下操作？如果您有多个参数，您将如何编写 @selector？

没有参数:

-(void)printText {
    NSLog(@"Fish");
}

[self performSelector:@selector(printText) withObject:nil afterDelay:0.25];

单个参数:

-(void)printText:(NSString *)myText {
    NSLog(@"Text = %@", myText);
}

[self performSelector:@selector(printText:) withObject:@"Cake" afterDelay:0.25];

两个参数:

-(void)printText:(NSString *)myText andMore:(NSString *)extraText {
    NSLog(@"Text = %@ and %@", myText, extraText);
}

[self performSelector:@selector(printText:andMore:) withObject:@"Cake" withObject:@"Chips"];

多个参数:(即超过 2 个)

NSInvocation

Answer 1

 - (id)performSelector:(SEL)aSelector
           withObject:(id)anObject  
           withObject:(id)anotherObject

来自Documentation :

This method is the same as performSelector: except that you can supply two arguments for aSelector. aSelector should identify a method that can take two arguments of type id. For methods with other argument types and return values, use NSInvocation.

所以在你的情况下你会使用:

[self performSelector:@selector(printText:andMore:)
           withObject:@"Cake"
           withObject:@"More Cake"]