从NSArray执行块？ [英] Executing Blocks From NSArray?

问题描述

我只是想，因为你可以处理块像对象，如果我创建两个，然后将它们添加到一个NSArray是有办法从数组中执行他们。

I was just thinking, as you can treat Blocks like objects if I create two of them and then add them to an NSArray is there a way to execute them from the array?

int (^Block_001)(void) = ^{ return 101; };
int (^Block_002)(void) = ^{ return 202; };
NSArray *array = [NSArray arrayWithObjects:Block_001, Block_002, nil];

编辑：更新为了清楚Per @ davedelong的优秀答案

Update for clarity Per @davedelong's excellent answer

int (^Block_001)(void) = [^{ return 101; } copy];
int (^Block_002)(void) = [^{ return 202; } copy];
NSArray *array = [NSArray arrayWithObjects:Block_001, Block_002, nil];

[Block_001 release];
[Block_002 release];

推荐答案

当然，你只需调用（）像任何其他块，但你需要类型转换从 NSArray 检索的值。这里是一个例子（添加了typedef，因为否则我的头疼）：

Sure, you just invoke it with () like any other block, but you need to typecast the value you retrieve from NSArray. Here's an example (with an added typedef, because otherwise my head hurts):

typedef int (^IntBlock)(void);
IntBlock Block_001 = ^{ return 101; };
IntBlock Block_002 = ^{ return 202; };
NSArray *array = [NSArray arrayWithObjects:Block_001, Block_002, nil];
int x = ((IntBlock)[array objectAtIndex:0]) (); // now x == 101

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