iOS 4 - 使用块作为类的成员

发布于 2024-10-05 14:28:45 字数 865 浏览 0 评论 0 原文

我希望有人可以帮助我理解块用作类成员时的语法。我有一些代码实际上工作得很好：

@class Structure;
typedef void (^StructureDeleteCallback)(Structure *);

@interface StructureListDelegate : NRFCTableDelegate
{
    StructureDeleteCallback _structureDeleteCallback;
}

@property (nonatomic, copy) StructureDeleteCallback structureDeleteCallback;

@end

这可以工作，但我想了解 typedef 语句的语法；以及是否确实需要使用 typedef。

我读到的内容表明，在这种情况下建议使用 typedef，因为它使代码更加清晰；但当我尝试在没有 typedef 的情况下执行此操作时，我根本无法编译它。我对 typedef 的理解是，语法基本上是：

typedef [actual type] [new name for type];

如：

typedef double CLLocationDegrees;

但我的 typedef 语句的语法与此不匹配。所以我的问题是：

我的 typedef 的语法如何声明与其他声明如此不同 typedef 语句/我使用的语法对编译器实际上意味着什么？
是否可以有一个块作为类的成员不使用 typedef？

原文

I was hoping someone could help me understand the syntax of blocks when used as members of a class. I have some code that's actually working just fine:

@class Structure;
typedef void (^StructureDeleteCallback)(Structure *);

@interface StructureListDelegate : NRFCTableDelegate
{
    StructureDeleteCallback _structureDeleteCallback;
}

@property (nonatomic, copy) StructureDeleteCallback structureDeleteCallback;

@end

This works, but I would like to understand the syntax of the typedef statement; and whether or not it's actually required to use typedef.

What I've read says that using typedef in this situation is recommended because it makes the code a lot clearer; but I've been unable to get it to compile at all when trying to do this without typedef. My understanding of typedef was that the syntax was basically:

typedef [actual type] [new name for type];

Such as:

typedef double CLLocationDegrees;

But the syntax of my typedef statement doesn't match this. So my questions are:

How can the syntax of my typedef
statement be so different from other
typedef statements / what does the syntax I'm using actually mean to the compiler?
Is it possible to
have a block as a member of a class
without using typedef?