一句话简介：最著名的OC开源网络库。
Github: 传送门
PS: 本拾遗系列文章只专注于代码以及工程层面知识点拾遗，架构层面作者文章已经进行了详细的讲解。
1. @import和modulemap
首先OC中的@import以及Swift中的import其实都是基于modulemap实现的。
- @import的使用可以参考：@import vs #import
- 关于modulemap相关的内容可以参考：Modular framework, creating and using them
2. 各种标记
- __unused: 避免因变量声明未使用造成的警告。
- ARC相关（如__autoreleasing）参考: iOS开发ARC内存管理技术要点
- NS_DESIGNATED_INITIALIZER 声明了designated初始化方法后，其余初始化方法如果没有调用designated初始化会有警告提示，具体可以参考: Xcode 6 Objective-C Modernization
- DEPRECATED_ATTRIBUTE（过期）、NS_SWIFT_NOTHROW（一些便于OC迁移Swift的标记）等
3. 宏
- FOUNDATION_EXPORT: 对于extern的兼容性封装，根据不同的平台，转化为对应的extern形式。
- NS_ASSUME_NONNULL_BEGIN、NS_ASSUME_NONNULL_END: 在宏范围内的变量、参数、返回值等都默认添加nonnull。
4. queryString转换的经典代码
经常被摘出来放到自己项目中使用。
/**
Returns a percent-escaped string following RFC 3986 for a query string key or value.
RFC 3986 states that the following characters are "reserved" characters.
- General Delimiters: ":", "#", "[", "]", "@", "?", "/"
- Sub-Delimiters: "!", "$", "&", "'", "(", ")", "*", "+", ",", ";", "="
In RFC 3986 - Section 3.4, it states that the "?" and "/" characters should not be escaped to allow
query strings to include a URL. Therefore, all "reserved" characters with the exception of "?" and "/"
should be percent-escaped in the query string.
- parameter string: The string to be percent-escaped.
- returns: The percent-escaped string.
*/
NSString * AFPercentEscapedStringFromString(NSString *string) {
static NSString * const kAFCharactersGeneralDelimitersToEncode = @":#[]@"; // does not include "?" or "/" due to RFC 3986 - Section 3.4
static NSString * const kAFCharactersSubDelimitersToEncode = @"!$&'()*+,;=";
NSMutableCharacterSet * allowedCharacterSet = [[NSCharacterSet URLQueryAllowedCharacterSet] mutableCopy];
[allowedCharacterSet removeCharactersInString:[kAFCharactersGeneralDelimitersToEncode stringByAppendingString:kAFCharactersSubDelimitersToEncode]];
// FIXME: https://github.com/AFNetworking/AFNetworking/pull/3028
// return [string stringByAddingPercentEncodingWithAllowedCharacters:allowedCharacterSet];
// 以下为针对非单字节字符的处理
static NSUInteger const batchSize = 50;
NSUInteger index = 0;
NSMutableString *escaped = @"".mutableCopy;
while (index < string.length) {
NSUInteger length = MIN(string.length - index, batchSize);
NSRange range = NSMakeRange(index, length);
// To avoid breaking up character sequences such as 👴🏻👮🏽
range = [string rangeOfComposedCharacterSequencesForRange:range];
NSString *substring = [string substringWithRange:range];
NSString *encoded = [substring stringByAddingPercentEncodingWithAllowedCharacters:allowedCharacterSet];
[escaped appendString:encoded];
index += range.length;
}
return escaped;
}[escaped appendString:encoded]
