关于AFNetworking 类库的一般用法

  (一)：关于 iOS 的两种开源网络请求类库   目前，在 iOS 以及 Mac应用中，使用较多的两种开源网络类库为 ASIHttpRequest和 AFNetworking.但是由于 ASIHttpRequest 已经停止更新，所以越来越多的开发者投入到了AFNetworking的使用和研究中。         在 github 上，其地址为 https://github.com/AFNetworking/AFNetworking/tree/master#requirements，有关信息查阅请自行前往。   (二):有关使用        创建工程后，将 AFNetworking和UIKit+AFNetworking导入到项目中，并添加MobileCoreServices.framework、SystemConfiguration.framework、Security.framework框架。在需要使用的文件中，统一导入#import"AFNetworking.h"。          在AFNetworking中，我们可以自行将其文件分为5个小类：1：关于发起网络请求(AFURLConnectionOperation、AFHTTPRequestOperation、AFHTTPRequestOperationManager)2:关于发起网络请求(其封装的 NSURLSession相关，需要 iOS7.0以后才支持，AFURLSessionManager、AFHTTPSessionManager)3:关于请求及相应的序列化(AFURLRequestSerialization、AFURLResponseSerialization)4：关于网络可到达性及连接状态发送改变(AFNetworkReachabilityManager)5:关于加密(AFSecurityPolicy)。a)发起一个GET 请求/******************使用AFHTTPRequestOperationManager发送GET请求*****************/    /*****     - (AFHTTPRequestOperation *)GET:(NSString *)URLString     parameters:(id)parameters     success:(void (^)(AFHTTPRequestOperation *operation, id responseObject))success     failure:(void (^)(AFHTTPRequestOperation *operation, NSError *error))failure;    *****/    //http://itunes.apple.com/lookup?id=794851407    NSString *URLString =@"http://itunes.apple.com/lookup?id=794851407";    //创建请求管理器    AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManagermanager];    //设置请求管理器的请求和响应数据的格式    manager.requestSerializer = [AFHTTPRequestSerializerserializer];    manager.responseSerializer =[AFJSONResponseSerializerserializer];    //发起 GET请求    [managerGET:URLString parameters:nilsuccess:^(AFHTTPRequestOperation *operation,id responseObject){       //请求成功回调        NSLog(@"responseObject %@",responseObject);    }failure:^(AFHTTPRequestOperation *operation,NSError *error){        //请求失败回调       NSLog(@"error is %d",[errorcode]);    }];b)发送一个POST1请求  /******************使用AFHTTPRequestOperationManager发送POST1请求*****************/        /*****     - (AFHTTPRequestOperation *)POST:(NSString *)URLString     parameters:(id)parameters     success:(void (^)(AFHTTPRequestOperation *operation, id responseObject))success     failure:(void (^)(AFHTTPRequestOperation *operation, NSError *error))failure;    *****/        NSString *URLString =@"http://itunes.apple.com/lookup";    //构建请求的参数   NSDictionary *para =@{@"id":@794851407};    //获取请求管理器    AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManagermanager];    //设置响应格式    manager.responseSerializer = [AFJSONResponseSerializerserializer];    //发起POST1请求    [managerPOST:URLString parameters:parasuccess:^(AFHTTPRequestOperation *operation,id responseObject){     //请求成功回调        NSLog(@"operation.responseObject %@",operation.response);       NSLog(@"responseObject %@",responseObject);    }failure:^(AFHTTPRequestOperation *operation,NSError *error){    //请求失败回调   NSLog(@"errorcode %d",[errorcode]);    }];c)发送一个POST2请求 /******************使用AFHTTPRequestOperationManager发送POST1请求*****************/        /*****    - (AFHTTPRequestOperation *)POST:(NSString *)URLString                      parameters:(id)parameters       constructingBodyWithBlock:(void (^)(id <AFMultipartFormData> formData))block                         success:(void (^)(AFHTTPRequestOperation *operation, id responseObject))success                         failure:(void (^)(AFHTTPRequestOperation *operation, NSError *error))failure    *****/

//获取请求管器

AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];

NSDictionary *parameters = @{@"foo": @"bar"};

NSURL *filePath = [NSURL fileURLWithPath:@"file://path/to/image.png"];

[manager POST:@"http://example.com/resources.json" parameters:parameters constructingBodyWithBlock:^(id<AFMultipartFormData> formData) {
[formData appendPartWithFileURL:filePath name:@"image" error:nil];
} success:^(AFHTTPRequestOperation *operation, id responseObject) {
NSLog(@"Success: %@", responseObject);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(@"Error: %@", error);
}];

d）使用AFHTTPRequestOperation发起请求

AFHTTPRequestOperation

 is a subclass of 

AFURLConnectionOperation

 forrequests using the HTTP or HTTPS protocols. It encapsulates the concept of acceptable status codes and content types, which determine the success or failure of a request.Although 

AFHTTPRequestOperationManager

 is usually the best way to go about making requests, 

AFHTTPRequestOperation

 canbe used by itself.AFHTTPRequestOperation是

AFURLConnectionOperation

 的子类，并使用HTTPor HTTPS协议发起请求。AFHTTPRequestOperation概括了关于请求的状态码和内容类型，决定了请求的成功与失败。尽管AFHTTPRequestOperationManager是通常关于发起请求最好的方式，但AFHTTPRequestOperation对象也能通过自身发起请求。

GET

 with 

AFHTTPRequestOperation

NSURL *URL = [NSURL URLWithString:@"http://example.com/resources/123.json"];
NSURLRequest *request = [NSURLRequest requestWithURL:URL];
AFHTTPRequestOperation *op = [[AFHTTPRequestOperation alloc] initWithRequest:request];
op.responseSerializer = [AFJSONResponseSerializer serializer];
[op setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
NSLog(@"JSON: %@", responseObject);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(@"Error: %@", error);
}];
[[NSOperationQueue mainQueue] addOperation:op];

e）Batch of Operations(批量请求)

NSMutableArray *mutableOperations = [NSMutableArray array];
for (NSURL *fileURL in filesToUpload) {
NSURLRequest *request = [[AFHTTPRequestSerializer serializer] multipartFormRequestWithMethod:@"POST" URLString:@"http://example.com/upload" parameters:nil constructingBodyWithBlock:^(id<AFMultipartFormData> formData) {
[formData appendPartWithFileURL:fileURL name:@"images[]" error:nil];
}];

AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];

[mutableOperations addObject:operation];
}

NSArray *operations = [AFURLConnectionOperation batchOfRequestOperations:@[...] progressBlock:^(NSUInteger numberOfFinishedOperations, NSUInteger totalNumberOfOperations) {
NSLog(@"%lu of %lu complete", numberOfFinishedOperations, totalNumberOfOperations);
} completionBlock:^(NSArray *operations) {
NSLog(@"All operations in batch complete");
}];
[[NSOperationQueue mainQueue] addOperations:operations waitUntilFinished:NO];

f）网络检测及连接状态改变1：

[[AFNetworkReachabilityManager sharedManager] setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
NSLog(@"Reachability: %@", AFStringFromNetworkReachabilityStatus(status));
}];

2：

NSURL *baseURL = [NSURL URLWithString:@"http://example.com/"];
AFHTTPRequestOperationManager *manager = [[AFHTTPRequestOperationManager alloc] initWithBaseURL:baseURL];

NSOperationQueue *operationQueue = manager.operationQueue;
[manager.reachabilityManager setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
switch (status) {
case AFNetworkReachabilityStatusReachableViaWWAN:
case AFNetworkReachabilityStatusReachableViaWiFi:
[operationQueue setSuspended:NO];
break;
case AFNetworkReachabilityStatusNotReachable:
default:
[operationQueue setSuspended:YES];
break;
}
}];

[manager.reachabilityManager startMonitoring];