AFNetworking的学习

AFNetworking是一个讨人喜欢的网络库,适用于iOS以及Mac OS X. 它构建于在 NSURLConnection, NSOperation, 以及其他熟悉的Foundation技术之上. 它拥有良好的架构,丰富的api,以及模块化构建方式,使得使用起来非常轻松.例如,他可以使用很轻松的方式从一个url来得到json数据:

NSURL *url = [NSURL URLWithString:@ "http://api.twitter.com/1/statuses/public_timeline.json" ];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) {
    NSLog(@ "Public Timeline: %@" , JSON);
} failure:nil];
[operation start];

综述

CORE:

　　AFURLConnectionOperation:一个 NSOperation 实现了NSURLConnection 的代理方法.

HTTP Requests:

　　AFHTTPRequestOperation:AFURLConnectionOperation的子类,当request使用的协议为HTTP和HTTPS时,它压缩了用于决定request是否成功的状态码和内容类型.
　　AFJSONRequestOperation:AFHTTPRequestOperation的一个子类,用于下载和处理jason response数据.
　　AFXMLRequestOperation:AFHTTPRequestOperation的一个子类,用于下载和处理xml response数据.
　　AFPropertyListRequestOperation:AFHTTPRequestOperation的一个子类,用于下载和处理property list response数据.

HTTP CLIENT:

　　AFHTTPClient:捕获一个基于http协议的网络应用程序的公共交流模式.包含:
使用基本的url相关路径来只做request，为request自动添加设置http headers.
使用http 基础证书或者OAuth来验证request
为由client制作的requests管理一个NSOperationQueue
从NSDictionary生成一个查询字符串或http bodies.
从request中构建多部件
自动的解析http response数据为相应的表现数据
在网络可达性测试用监控和响应变化.

IMAGES

　　AFImageRequestOperation:一个AFHTTPRequestOperation的子类,用于下载和处理图片.
　　UIImageView+AFNetworking:添加一些方法到UIImageView中,为了从一个URL中异步加载远程图片

例子程序

XML REQUEST

NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@ "http://api.flickr.com/services/rest/?method=flickr.groups.browse&api_key=b6300e17ad3c506e706cb0072175d047&cat_id=34427469792%40N01&format=rest" ]];
AFXMLRequestOperation *operation = [AFXMLRequestOperation XMLParserRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, NSXMLParser *XMLParser) {
  XMLParser.delegate = self;
  [XMLParser parse];
} failure:nil];
[operation start];

IMAGE REQUEST

UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0.0f, 0.0f, 100.0f, 100.0f)];
[imageView setImageWithURL:[NSURL URLWithString:@ "http://i.imgur.com/r4uwx.jpg" ] placeholderImage:[UIImage imageNamed:@ "placeholder-avatar" ]];

API CLIENT REQUEST

// AFGowallaAPIClient is a subclass of AFHTTPClient, which defines the base URL and default HTTP headers for NSURLRequests it creates
[[AFGowallaAPIClient sharedClient] getPath:@ "/spots/9223" parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) {
    NSLog(@ "Name: %@" , [responseObject valueForKeyPath:@ "name" ]);
    NSLog(@ "Address: %@" , [responseObject valueForKeyPath:@ "address.street_address" ]);
} failure:nil];

FILE UPLOAD WITH PROGRESS CALLBACK

NSURL *url = [NSURL URLWithString:@ "http://api-base-url.com" ];
AFHTTPClient *httpClient = [[AFHTTPClient alloc] initWithBaseURL:url];
NSData *imageData = UIImageJPEGRepresentation([UIImage imageNamed:@ "avatar.jpg" ], 0.5);
NSMutableURLRequest *request = [httpClient multipartFormRequestWithMethod:@ "POST" path:@ "/upload" parameters:nil constructingBodyWithBlock: ^(id formData) {
    [formData appendPartWithFileData:imageData name:@ "avatar" fileName:@ "avatar.jpg" mimeType:@ "image/jpeg" ];
}];

AFHTTPRequestOperation *operation = [[[AFHTTPRequestOperation alloc] initWithRequest:request] autorelease];
[operation setUploadProgressBlock:^(NSInteger bytesWritten, long long totalBytesWritten, long long totalBytesExpectedToWrite) {
    NSLog(@ "Sent %lld of %lld bytes" , totalBytesWritten, totalBytesExpectedToWrite);
}];
[operation start];

STREAMING REQUEST

NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@ "http://localhost:8080/encode" ]];
AFHTTPRequestOperation *operation = [[[AFHTTPRequestOperation alloc] initWithRequest:request] autorelease];
operation.inputStream = [NSInputStream inputStreamWithFileAtPath:[[NSBundle mainBundle] pathForResource:@ "large-image" ofType:@ "tiff" ]];
operation.outputStream = [NSOutputStream outputStreamToMemory];
[operation start];