AFHTTPSessionManager相对来说比较好理解，代码也比较短。但却是我们平时可能使用最多的类。
AFNetworking 3.0 源码解读（一）之 AFNetworkReachabilityManager
AFNetworking 3.0 源码解读（二）之 AFSecurityPolicy
AFNetworking 3.0 源码解读（三）之 AFURLRequestSerialization
AFNetworking 3.0 源码解读（四）之 AFURLResponseSerialization
AFNetworking 3.0 源码解读（五）之 AFURLSessionManager
前言
AFHTTPSessionManager是AFURLSessionManager的子类，是专门为HTTP请求设计的。里边涉及到了GET,POST,PUT,DELETE 等等HTTPMehtod。因此我们要想正确的使用各种方法，就要理解每个method的含义。
可以通过这篇文章来了解HTTP Method详细解读(GET HEAD POST OPTIONS PUT DELETE TRACE CONNECT)
1.相对路径(relative)
假如有一个基础路径NSURL *baseURL = [NSURL URLWithString:@"http://example.com/v1/"];我们暂时命名为baseURL.所谓 相对 肯定跟这个baseURL有关系。
我们可以通过NSURL +URLWithString:relativeToURL:这个方法来获取一个路径，至于怎么使用，我们通过一个例子来说明：
NSURL *baseURL = [NSURL URLWithString:@"http://example.com/v1/"];
[NSURL URLWithString:@"foo" relativeToURL:baseURL]; // http://example.com/v1/foo
[NSURL URLWithString:@"foo?bar=baz" relativeToURL:baseURL]; // http://example.com/v1/foo?bar=baz
[NSURL URLWithString:@"/foo" relativeToURL:baseURL]; // http://example.com/foo
[NSURL URLWithString:@"foo/" relativeToURL:baseURL]; // http://example.com/v1/foo
[NSURL URLWithString:@"/foo/" relativeToURL:baseURL]; // http://example.com/foo/
[NSURL URLWithString:@"http://example2.com/" relativeToURL:baseURL]; // http://example2.com/
至于 绝对路径 和 相对路径 的定义，使用方法，优缺点，这里就不提了，大家可以自行了解。说一下为什么使用相对路径吧。
在真实开发中，一般都会有一个线上的服务器和一下测试服务器，当然也可能多个。在ios开发中切换开发环境有好几种方法，
- 通过target
- 自定义一个字段HTTPURL，用它来控制路径
- 通过相对路径来切换接口
2.GET
// 使用GET 方法获取数据，不带进度
- (NSURLSessionDataTask *)GET:(NSString *)URLString
parameters:(id)parameters
success:(void (^)(NSURLSessionDataTask *task, id responseObject))success
failure:(void (^)(NSURLSessionDataTask *task, NSError *error))failure
{
return [self GET:URLString parameters:parameters progress:nil success:success failure:failure];
}
// 使用GET 方法获取数据，带进度
- (NSURLSessionDataTask *)GET:(NSString *)URLString
parameters:(id)parameters
progress:(void (^)(NSProgress * _Nonnull))downloadProgress
success:(void (^)(NSURLSessionDataTask * _Nonnull, id _Nullable))success
failure:(void (^)(NSURLSessionDataTask * _Nullable, NSError * _Nonnull))failure
{
NSURLSessionDataTask *dataTask = [self dataTaskWithHTTPMethod:@"GET"
URLString:URLString
parameters:parameters
uploadProgress:nil
downloadProgress:downloadProgress
success:success
failure:failure];
[dataTask resume];
return dataTask;
}
3.HEAD
// 使用HEAD 方法获取数据，
- (NSURLSessionDataTask *)HEAD:(NSString *)URLString
parameters:(id)parameters
success:(void (^)(NSURLSessionDataTask *task))success
failure:(void (^)(NSURLSessionDataTask *task, NSError *error))failure
{
NSURLSessionDataTask *dataTask = [self dataTaskWithHTTPMethod:@"HEAD" URLString:URLString parameters:parameters uploadProgress:nil downloadProgress:nil success:^(NSURLSessionDataTask *task, __unused id responseObject) {
if (success) {
success(task);
}
} failure:failure];
[dataTask resume];
return dataTask;
}
4.POST
- (NSURLSessionDataTask *)POST:(NSString *)URLString
parameters:(id)parameters
success:(void (^)(NSURLSessionDataTask *task, id responseObject))success
failure:(void (^)(NSURLSessionDataTask *task, NSError *error))failure
{
return [self POST:URLString parameters:parameters progress:nil success:success failure:failure];
}
- (NSURLSessionDataTask *)POST:(NSString *)URLString
parameters:(id)parameters
progress:(void (^)(NSProgress * _Nonnull))uploadProgress
success:(void (^)(NSURLSessionDataTask * _Nonnull, id _Nullable))success
failure:(void (^)(NSURLSessionDataTask * _Nullable, NSError * _Nonnull))failure
{
NSURLSessionDataTask *dataTask = [self dataTaskWithHTTPMethod:@"POST" URLString:URLString parameters:parameters uploadProgress:uploadProgress downloadProgress:nil success:success failure:failure];
[dataTask resume];
return dataTask;
}
5.上传数据
- (NSURLSessionDataTask *)POST:(NSString *)URLString
parameters:(nullable id)parameters
constructingBodyWithBlock:(nullable void (^)(id<AFMultipartFormData> _Nonnull))block
success:(nullable void (^)(NSURLSessionDataTask * _Nonnull, id _Nullable))success
failure:(nullable void (^)(NSURLSessionDataTask * _Nullable, NSError * _Nonnull))failure
{
return [self POST:URLString parameters:parameters constructingBodyWithBlock:block progress:nil success:success failure:failure];
}
- (NSURLSessionDataTask *)POST:(NSString *)URLString
parameters:(id)parameters
constructingBodyWithBlock:(void (^)(id <AFMultipartFormData> formData))block
progress:(nullable void (^)(NSProgress * _Nonnull))uploadProgress
success:(void (^)(NSURLSessionDataTask *task, id responseObject))success
failure:(void (^)(NSURLSessionDataTask *task, NSError *error))failure
{
NSError *serializationError = nil;
NSMutableURLRequest *request = [self.requestSerializer multipartFormRequestWithMethod:@"POST" URLString:[[NSURL URLWithString:URLString relativeToURL:self.baseURL] absoluteString] parameters:parameters constructingBodyWithBlock:block error:&serializationError];
if (serializationError) {
if (failure) {
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wgnu"
dispatch_async(self.completionQueue ?: dispatch_get_main_queue(), ^{
failure(nil, serializationError);
});
#pragma clang diagnostic pop
}
return nil;
}
__block NSURLSessionDataTask *task = [self uploadTaskWithStreamedRequest:request progress:uploadProgress completionHandler:^(NSURLResponse * __unused response, id responseObject, NSError *error) {
if (error) {
if (failure) {
failure(task, error);
}
} else {
if (success) {
success(task, responseObject);
}
}
}];
[task resume];
return task;
}
6.PUT
- (NSURLSessionDataTask *)PUT:(NSString *)URLString
parameters:(id)parameters
success:(void (^)(NSURLSessionDataTask *task, id responseObject))success
failure:(void (^)(NSURLSessionDataTask *task, NSError *error))failure
{
NSURLSessionDataTask *dataTask = [self dataTaskWithHTTPMethod:@"PUT" URLString:URLString parameters:parameters uploadProgress:nil downloadProgress:nil success:success failure:failure];
[dataTask resume];
return dataTask;
}
7.PATCH
- (NSURLSessionDataTask *)PATCH:(NSString *)URLString
parameters:(id)parameters
success:(void (^)(NSURLSessionDataTask *task, id responseObject))success
failure:(void (^)(NSURLSessionDataTask *task, NSError *error))failure
{
NSURLSessionDataTask *dataTask = [self dataTaskWithHTTPMethod:@"PATCH" URLString:URLString parameters:parameters uploadProgress:nil downloadProgress:nil success:success failure:failure];
[dataTask resume];
return dataTask;
}
8.DELETE
- (NSURLSessionDataTask *)DELETE:(NSString *)URLString
parameters:(id)parameters
success:(void (^)(NSURLSessionDataTask *task, id responseObject))success
failure:(void (^)(NSURLSessionDataTask *task, NSError *error))failure
{
NSURLSessionDataTask *dataTask = [self dataTaskWithHTTPMethod:@"DELETE" URLString:URLString parameters:parameters uploadProgress:nil downloadProgress:nil success:success failure:failure];
[dataTask resume];
return dataTask;
}
9.私有方法
- (NSURLSessionDataTask *)dataTaskWithHTTPMethod:(NSString *)method
URLString:(NSString *)URLString
parameters:(id)parameters
uploadProgress:(nullable void (^)(NSProgress *uploadProgress)) uploadProgress
downloadProgress:(nullable void (^)(NSProgress *downloadProgress)) downloadProgress
success:(void (^)(NSURLSessionDataTask *, id))success
failure:(void (^)(NSURLSessionDataTask *, NSError *))failure
{
NSError *serializationError = nil;
NSMutableURLRequest *request = [self.requestSerializer requestWithMethod:method URLString:[[NSURL URLWithString:URLString relativeToURL:self.baseURL] absoluteString] parameters:parameters error:&serializationError];
if (serializationError) {
if (failure) {
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wgnu"
dispatch_async(self.completionQueue ?: dispatch_get_main_queue(), ^{
failure(nil, serializationError);
});
#pragma clang diagnostic pop
}
return nil;
}
__block NSURLSessionDataTask *dataTask = nil;
dataTask = [self dataTaskWithRequest:request
uploadProgress:uploadProgress
downloadProgress:downloadProgress
completionHandler:^(NSURLResponse * __unused response, id responseObject, NSError *error) {
if (error) {
if (failure) {
failure(dataTask, error);
}
} else {
if (success) {
success(dataTask, responseObject);
}
}
}];
return dataTask;
}
这篇文章确实比较简单，有了前几篇文章的铺垫，到了我们真正使用的时候，一切都变得那么简单自然啊.我们已经不知不觉中学到了很多知识，但有一点，知识这东西，要反复的记忆才能记住。举个例子吧 ，平时可能我们需要在web端查看json数据，当我们把参数拼接到paramter中，该怎么查看呢？
- 找到
AFURLRequestSerialization这个.m - 找到
requestBySerializingRequest: withParameters: error:这个方法 NSLog(@"URL: %@",mutableRequest.URL.absoluteString);
说明
接下来先把 AFNetworking 的分类再解析完，然后开始搭建网络框架。
