<h2>afn封装</h2>    <p>一旦AFN有较大的变动，用到AFN的项目需要更改很多的地方，为了避免这种情况，一般会对AFN封装出一个类，这样有了变动之后，只需要更改这个类即可（代码如下）</p>    <h3>.h文件</h3>    <pre>  <code>#import <Foundation/Foundation.h>    typedef NS_ENUM(NSInteger, RequestMethod)  {      post,      get  };    @interface NetworkTools : NSObject    + (instancetype)shareNetworkTools;    /**   * requestMethod:请求方式   * urlString:请求地址   * parameters:请求参数   * responseBlock:请求成功或失败的回调   */    - (void)requestWithMethod:(RequestMethod)requestMethod andUrlString:(NSString *)urlString andParameters:(id) parameters andFinished:(void(^)(id response, NSError *error))responseBlock;    /**   * data:上传资料   * name:上传资料的名字   * urlString:请求地址   * parameters:请求参数   * responseBlock:请求成功或失败的回调   */    - (void)requestWithData:(NSData *)data andName:(NSString *)name andUrlString:(NSString *)urlString andParameters:(id) parameters andFinished:(void(^)(id response, NSError *error))responseBlock;    @end</code></pre>    <h3>.m文件</h3>    <pre>  <code>#import "NetworkTools.h"  #import <AFNetworking.h>    @implementation NetworkTools    + (instancetype)shareNetworkTools  {      static NetworkTools *networkTools = nil;      static dispatch_once_t onceToken;      dispatch_once(&onceToken, ^{          networkTools = [[NetworkTools alloc] init];      });      return networkTools;  }    - (void)requestWithMethod:(RequestMethod)requestMethod andUrlString:(NSString *)urlString andParameters:(id) parameters andFinished:(void(^)(id response, NSError *error))responseBlock  {      // 定义成功的block      void (^success)(NSURLSessionDataTask *dataTask, id responseObject) = ^(NSURLSessionDataTask *dataTask,id responseObject)      {          responseBlock(responseObject, nil);      };      // 定义失败的block      void (^failure)(NSURLSessionDataTask *dataTask,NSError *error) = ^(NSURLSessionDataTask *dataTask,NSError *error)      {          responseBlock(nil, error);      };      if (requestMethod == get) {          [[AFHTTPSessionManager manager] GET:urlString parameters:parameters success:success failure:failure];      } else {          [[AFHTTPSessionManager manager] POST:urlString parameters:parameters success:success failure:failure];      }  }    - (void)requestWithData:(NSData *)data andName:(NSString *)name andUrlString:(NSString *)urlString andParameters:(id) parameters andFinished:(void(^)(id response, NSError *error))responseBlock  {      void (^success)(NSURLSessionDataTask *dataTask, id responseObject) = ^(NSURLSessionDataTask *dataTask,id responseObject)      {          responseBlock(responseObject, nil);      };      void (^failure)(NSURLSessionDataTask *dataTask,NSError *error) = ^(NSURLSessionDataTask *dataTask,NSError *error)      {          responseBlock(nil, error);      };      [[AFHTTPSessionManager manager] POST:urlString parameters:parameters constructingBodyWithBlock:^(id<AFMultipartFormData>  _Nonnull formData) {          [formData appendPartWithFileData:data name:name fileName:@"aa" mimeType:@"application/octet-stream"];      } success:success failure:failure];  }    @end</code></pre>    <p><br> via：http://www.jianshu.com/p/37ba814bb66d<br>  </p>