AFHTTPRequestSerialization:
@方法1
- (NSMutableURLRequest *)requestWithMethod:(NSString *)method
URLString:(NSString *)URLString
parameters:(id)parameters
error:(NSError *__autoreleasing *)error ／／设置请求方法，设置请求url，内部调用@方法2设置请求头和路径参数或者httpbody
@方法2
- (NSURLRequest *)requestBySerializingRequest:(NSURLRequest *)request
withParameters:(id)parameters
error:(NSError *__autoreleasing *)error／／设置请求头，根据paramters拼接请求路径或设置httpbody
@方法3
- (NSMutableURLRequest *)multipartFormRequestWithMethod:(NSString *)method
URLString:(NSString *)URLString
parameters:(NSDictionary *)parameters
constructingBodyWithBlock:(void (^)(id <AFMultipartFormData> formData))block
error:(NSError *__autoreleasing *)error／／内部调用@方法1设置请求方法，设置请求url，设置请求头
调用AFStreamingMultipartFormData初始化@方法1，根据params组成AFQueryStringPair对象数组，遍历取出AFQueryPair的value和key，调用AFStreamingMultipartFormData 的@方法2拼接数据，调用block，在外部调用AFMultipartFormData协议方法，通过调用AFStreamingMultipartFormData的@方法2，拼接数据。最后调用AFStreamingMultipartFormData的@方法4，设置请求头content-type和
Content-Length以及httpbodystream
AFStreamingMultipartFormData
@方法1
- (instancetype)initWithURLRequest:(NSMutableURLRequest *)urlRequest
stringEncoding:(NSStringEncoding)encoding／／持有NSMutableRequest,设置字符编码，随机设置boundary，初始化
AFMultipartBodyStream对象
@方法2
- (void)appendPartWithFormData:(NSData *)data
name:(NSString *)name／／设置字典headers，key为Content-Disposition，value为：[NSString stringWithFormat:@"form-data; name=\"%@\"", name]，传递headers和data调用@方法3组装数据
@方法3
- (void)appendPartWithHeaders:(NSDictionary *)headers
body:(NSData *)body／／设置一个AFHTTPBodyPart对象，赋值对象的header和body属性值，调用AFMultipartBodyStream@方法3将该对象添加到AFMultipartBodyStream的HTTPBodyParts数组中
@方法4
- (NSMutableURLRequest *)requestByFinalizingMultipartFormData/／设置请求头content-type和Content-Length以及httpbodystream,
AFMultipartBodyStream
@方法1
- (instancetype)initWithStringEncoding:(NSStringEncoding)encoding／／设置字符编码，初始化HTTPBodyParts数组
@方法2
- (NSInteger)read:(uint8_t *)buffer
maxLength:(NSUInteger)maxLength/／调用AFHTTPBodyPart@方法1逐段读书数据到buffer中
@方法3
- (void)appendHTTPBodyPart:(AFHTTPBodyPart *)bodyPart／／追加HTTPBodyPart对象到HTTPBodyParts数组
AFHTTPBodyPart
@方法1
- (NSInteger)read:(uint8_t *)buffer
maxLength:(NSUInteger)length／／根据当前所处阶段值AFHTTPBodyPartReadPhase，获取该阶段的内容，如
AFEncapsulationBoundaryPhase&AFFinalBoundaryPhase就是boundary的内容，将内容转为data，调用@方法2取出data的字节赋值给buffer
AFHeaderPhase就是AFHTTPBodyPart的header值，将内容转为data，调用@方法2取出data的字节赋值给buffer
AFBodyPhase就是AFHTTPBodyPart的body值，body通过inputstream引用起来，通过NSInputStream流读取
@方法2
- (NSInteger)readData:(NSData *)data
intoBuffer:(uint8_t *)buffer
maxLength:(NSUInteger)length／／取出data的字节赋值给buffer
@方法3
- (NSInputStream *)inputStream {／／将body转为NSInputStream
if (!_inputStream) {
if ([self.body isKindOfClass:[NSData class]]) {
_inputStream = [NSInputStream inputStreamWithData:self.body];
} else if ([self.body isKindOfClass:[NSURL class]]) {
_inputStream = [NSInputStream inputStreamWithURL:self.body];
} else if ([self.body isKindOfClass:[NSInputStream class]]) {
_inputStream = self.body;
} else {
_inputStream = [NSInputStream inputStreamWithData:[NSData data]];
}
}
return _inputStream;
}