目标 C 中的静态初始值设定项 [英] static initializers in objective C

问题描述

如何在objective-c 中创建静态初始值设定项(如果我的术语正确的话).基本上我想做这样的事情:

How do I make static initializers in objective-c (if I have the term correct). Basically I want to do something like this:

static NSString* gTexts[] = 
{
    @"A string.",
    @"Another string.",
}

但我想做这个更像结构的事情，即对于这个数组中的每个元素，不仅有一个 NSString，而是一个 NSString 加上一个包含可变数量的 MyObjectType 的 NSArray，其中 MyObjectType 将包含一个 NSString，一对整数等

But I want to do this more struct-like, i.e. have not just an NSString for each element in this array, but instead an NSString plus one NSArray that contains a variable number of MyObjectType where MyObjectType would contain an NSString, a couple ints, etc.

推荐答案

由于 NSArrays 和 MyObjectTypes 是堆分配的对象，您不能在静态上下文中创建它们.您可以声明变量，然后在方法中初始化它们.

Since NSArrays and MyObjectTypes are heap-allocated objects, you cannot create them in a static context. You can declare the variables, and then initialize them in a method.

所以你不能这样做:

static NSArray *myStaticArray = [[NSArray alloc] init....];

相反，您必须:

static NSArray *myStaticArray = nil;

- (void) someMethod {
  if (myStaticArray == nil) {
    myStaticArray = [[NSArray alloc] init...];
  }
}

这发生适用于常量字符串(@"foo" 等)，因为它们不是堆分配的.它们被硬编码到二进制文件中.

This happens to work with constant strings (@"foo", etc), because they are not heap-allocated. They are hardcoded into the binary.

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