AFNetwork是一個輕量級的網絡請求api類庫。是以NSURLConnection, NSOperation和其它方法為基礎的。


以下這個樣例是用來處理json請求的： 
NSURL *url = [NSURL URLWithString:@"https://alpha-api.app.net/stream/0/posts/stream/global"]; 
NSURLRequest *request = [NSURLRequest requestWithURL:url]; 
AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) { 
    NSLog(@"App.net Global Stream: %@", JSON); 
} failure:nil]; 
[operation start]; 
用法： 
1.下載AFNetwork， 點擊下載 
2.將目錄名稱為AFNetworking拖入到你的工程項目就可以 
常見問題： 
1.  AFNetworking作用都有哪些？ 
NSURLConnection 提供了+sendAsynchronousRequest:queue:completionHandler: 和+sendAsynchronousRequest:queue:completionHandler: ，可是AFNetworking提供了更好的功能 
＊AFURLConnectionOperation和它的子類繼承NSOperation的，同意請求被取消，暫停/恢復和由NSOperationQueue進行管理。
 
 
＊AFURLConnectionOperation也能夠讓你輕松得完畢上傳和下載，處理驗證。監控上傳和下載進度，控制的緩存。
 
＊AFHTTPRequestOperation和它得子類能夠基於http狀態和 內容列下來區分是否成功請求了 
＊AFNetworking能夠將遠程媒體數據類型（NSData）轉化為可用的格式。比方如JSON，XML，圖像和plist。
 
＊AFHTTPClient提供了一個方便的網絡交互接口，包含默認頭，身份驗證。是否連接到網絡，批量處理操作。查詢字符串參數序列化。已經多種表單請求 
＊的UIImageView+ AFNetworking添加了一個方便的方法來異步載入圖像。 
2. AFNetworking是否支持緩存？ 
能夠。NSURLCache及其子類提供了非常多高級接口用於處理緩存 
假設你想將緩存存儲再磁盤，推薦使用SDURLCache 
3.怎樣使用AFNetworking上傳一個文件？ 
NSData *imageData = UIImagePNGRepresentation(image); 
NSURLRequest *request = [client multipartFormRequestWithMethod:@"POST" path:@"/upload" parameters:nil constructingBodyWithBlock: ^(id <AFMultipartFormData> formData) { 
  [formData appendPartWithFileData:imageData mimeType:@"image/png" name:@"avatar"]; 
}]; 
4.怎樣使用AFNetworking下載一個文件？ 
先創建一個 AFURLConnectionOperation對象，然後再使用它的屬性 outputStream進行處理 
operation.outputStream = [NSOutputStream outputStreamToFileAtPath:@"download.zip" append:NO]; 
5.怎樣解決：SystemConfiguration framework not found in project 
請導入： 
#import <SystemConfiguration/SystemConfiguration.h> 
#import <MobileCoreServices/MobileCoreServices.h> 
6.當應用程序退出時。怎樣保持持續的請求？ 
AFURLConnectionOperation有一個叫 setShouldExecuteAsBackgroundTaskWithExpirationHandler:的方法用於處理在應用程序進入後臺後，進行持續的請求 
[self setShouldExecuteAsBackgroundTaskWithExpirationHandler:^{ 
}]; 
一些實例： 
1.XML 請求 
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]; 
2.圖片請求： 
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"]]; 
3.圖片上傳處理，監測上傳狀態： 
didiwei  17:28:57 
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 <AFMultipartFormData>formData) { 
    [formData appendPartWithFileData:imageData name:@"avatar" fileName:@"avatar.jpg" mimeType:@"image/jpeg"]; 
}]; 
AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request]; 
[operation setUploadProgressBlock:^(NSUInteger bytesWritten, long long totalBytesWritten, long long totalBytesExpectedToWrite) { 
    NSLog(@"Sent %lld of %lld bytes", totalBytesWritten, totalBytesExpectedToWrite); 
}]; 
[operation start]; 
4.在線流媒體請求 
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://localhost:8080/encode"]]; 
AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request]; 
operation.inputStream = [NSInputStream inputStreamWithFileAtPath:[[NSBundle mainBundle] pathForResource:@"large-image" ofType:@"tiff"]]; 
operation.outputStream = [NSOutputStream outputStreamToMemory]; 
[operation start];

AFNetWorking能做什麽