iPhone：如何在执行选择器方法中传递参数？

Question

在iPhone中有没有什么办法在[self performSelector]方法中传参数？这个方法中有多少个最大参数？如果是的话，请给我任何链接或任何想法来开发此功能。

Answer 1

http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Protocols/NSObject_Protocol/Reference/NSObject.html#//apple_ref/occ/intfm/NSObject/performSelector:withObject：

使用

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

侧击

Answer 2

可以传递只有一个参数与performSelector

[self performSelector:@selector(aSelector) withObject:(id)object]; 

Answer 3

NSObject的有以下：

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

和

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

你总是可以让anObject是一个NSArray，NSDictionary的或其他自定义类，将包含参数为你

Answer 4

你有三种可能性，整体：

1. – performSelector: 
2. – performSelector:withObject: 
3. – performSelector:withObject:withObject: 

第一个根本没有论据;第二，一个论点;第三，两个论点。

Answer 5

如果你想通过不超过两个参数，使用

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

之一，如果你需要传递更多的参数，使用NSInvocation。这里是docs。

UPD：这里是一个NSInvocation的例子。再说了，你要发送doThis:andThis:andThis:到targetObjectMyClass类型：

SEL message = @selector(doThis:andThis:andThis:); 
NSMethodSignature *signature = [MyClass methodSignatureForSelector:message]; 
NSInvocation  *invocation = [NSInvocation invocationWithMethodSignature:signature]; 

[invocation setTarget:targetObject]; 
[invocation setSelector:message]; 
[invocation setArgument:&fist atIndex:2]; // Note that you need to put & 
[invocation setArgument:&second atIndex:3]; // as you send a pointer 
[invocation setArgument:&third atIndex:4]; // Also the indexing starts from 2 
              // 0 is for target, 1 is for selector 
[invocation invoke]; 

Answer 6

多个对象 - 只需创建你的对象数组/字典，并通过这个数组/词典

[self performSelector:@selector(aSelector) withObject:myArray];