https://github.com/AFNetworking/AFNetworking

与asi-http-request功能类似的网络库，不过是基于 和  的,同样支持iOS与MacOS双平台。目前的更新比较频繁，适合新项目使用，而且使用起来也更简单。

操作JSON

- (IBAction)jsonTapped:(id)sender {    // 1    NSString *weatherUrl = [NSString stringWithFormat:@"%@weather.php?format=json", BaseURLString];    NSURL *url = [NSURL URLWithString:weatherUrl];    NSURLRequest *request = [NSURLRequest requestWithURL:url];     // 2    AFJSONRequestOperation *operation =    [AFJSONRequestOperation JSONRequestOperationWithRequest:request        // 3        success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) {            self.weather  = (NSDictionary *)JSON;            self.title = @"JSON Retrieved";            [self.tableView reloadData];        }        // 4        failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON) {            UIAlertView *av = [[UIAlertView alloc] initWithTitle:@"Error Retrieving Weather"                                                         message:[NSString stringWithFormat:@"%@",error]                                                        delegate:nil                                               cancelButtonTitle:@"OK" otherButtonTitles:nil];            [av show];        }];     // 5    [operation start];}

1. 根据基本的URL构造出完整的一个URL。然后通过这个完整的URL获得一个NSURL对象，然后根据这个url获得一个NSURLRequest.
2. AFJSONRequestOperation 是一个功能完整的类（all-in-one）— 整合了从网络中获取数据并对JSON进行解析。
3. 当请求成功，则运行成功块（success block）。在本示例中，把解析出来的天气数据从JSON变量转换为一个字典（dictionary），并将其存储在属性 weather 中.
4. 如果运行出问题了，则运行失败块（failure block），比如网络不可用。如果failure block被调用了，将会通过提示框显示出错误信息。

 

操作Property Lists(plists)

-(IBAction)plistTapped:(id)sender{    NSString *weatherUrl = [NSString stringWithFormat:@"%@weather.php?format=plist",BaseURLString];    NSURL *url = [NSURL URLWithString:weatherUrl];    NSURLRequest *request = [NSURLRequest requestWithURL:url];     AFPropertyListRequestOperation *operation =    [AFPropertyListRequestOperation propertyListRequestOperationWithRequest:request        success:^(NSURLRequest *request, NSHTTPURLResponse *response, id propertyList) {            self.weather  = (NSDictionary *)propertyList;            self.title = @"PLIST Retrieved";            [self.tableView reloadData];        }        failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id propertyList) {            UIAlertView *av = [[UIAlertView alloc] initWithTitle:@"Error Retrieving Weather"                              message:[NSString stringWithFormat:@"%@",error]                                                        delegate:nil                                               cancelButtonTitle:@"OK"                                               otherButtonTitles:nil];            [av show];    }];     [operation start];}

上面的代码几乎与JSON版的一致，只不过将操作（operation）的类型从AFJSONOperation 修改为 AFPropertyListOperation.

操作XML

- (IBAction)xmlTapped:(id)sender{    NSString *weatherUrl = [NSString stringWithFormat:@"%@weather.php?format=xml",BaseURLString];    NSURL *url = [NSURL URLWithString:weatherUrl];    NSURLRequest *request = [NSURLRequest requestWithURL:url];     AFXMLRequestOperation *operation =    [AFXMLRequestOperation XMLParserRequestOperationWithRequest:request        success:^(NSURLRequest *request, NSHTTPURLResponse *response, NSXMLParser *XMLParser) {            //self.xmlWeather = [NSMutableDictionary dictionary];            XMLParser.delegate = self;            [XMLParser setShouldProcessNamespaces:YES];            [XMLParser parse];        }        failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, NSXMLParser *XMLParser) {            UIAlertView *av = [[UIAlertView alloc] initWithTitle:@"Error Retrieving Weather"                                                         message:[NSString stringWithFormat:@"%@",error]                                                        delegate:nil                                               cancelButtonTitle:@"OK"                                               otherButtonTitles:nil];            [av show];    }];     [operation start];}

到现在为止，这看起来跟之前处理JSON和plist很类似。最大的改动就是在成功块（success block）中, 在这里不会传递给你一个预处理好的NSDictionary对象. 而是AFXMLRequestOperation实例化的NSXMLParse对象，这个对象将用来处理繁重的XML解析任务。

NSXMLParse对象有一组delegate方法是你需要实现的 — 用来获得XML数据。注意，在上面的代码中我将XMLParser的delegate设置为self, 因此WTTableViewController将用来处理XML的解析任务。

下载图片

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"]];

- (IBAction)updateBackgroundImage:(id)sender {     //Store this image on the same server as the weather canned files    NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.scott-sherwood.com/wp-content/uploads/2013/01/scene.png"]];    AFImageRequestOperation *operation = [AFImageRequestOperation imageRequestOperationWithRequest:request        imageProcessingBlock:nil        success:^(NSURLRequest *request, NSHTTPURLResponse *response, UIImage *image) {            self.backgroundImageView.image = image;            [self saveImage:image withFilename:@"background.png"];        }        failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error) {            NSLog(@"Error %@",error);    }];    [operation start];}

-(void)saveImage:(UIImage *)image withFilename:(NSString *)filename{        NSString *path;    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);    path = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"WeatherHTTPClientImages/"];            BOOL isDir;        if(![[NSFileManager defaultManager] fileExistsAtPath:path isDirectory:&isDir]){        if(!isDir){            NSError *error;            [[NSFileManager defaultManager] createDirectoryAtPath:path withIntermediateDirectories:YES attributes:nil error:&error];                        NSLog(@"%@",error);        }    }        path = [path stringByAppendingPathComponent:filename];    NSData *imageData = UIImagePNGRepresentation(image);    NSLog(@"Written: %d",[imageData writeToFile:path atomically:YES]);}

 

AFHTTPClient

AFHTTPClient一般是给它设置一个基本的URL，然后用AFHTTPClient进行多个请求（而不是像之前的那样，每次请求的时候，都创建一个AFHTTPClient）。

- (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex{        if(buttonIndex==0){        NSURL *baseURL = [NSURL URLWithString:[NSString stringWithFormat:BaseURLString]];        NSDictionary *parameters = [NSDictionary dictionaryWithObject:@"json" forKey:@"format"];                AFHTTPClient *client = [[AFHTTPClient alloc] initWithBaseURL:baseURL];        [client registerHTTPOperationClass:[AFJSONRequestOperation class]];        [client setDefaultHeader:@"Accept" value:@"application/json"];                [client postPath:@"weather.php"              parameters:parameters                 success:^(AFHTTPRequestOperation *operation, id responseObject) {                     self.weather = responseObject;                     self.title = @"HTTP POST";                     [self.tableView reloadData];                 }                 failure:^(AFHTTPRequestOperation *operation, NSError *error) {                     UIAlertView *av = [[UIAlertView alloc] initWithTitle:@"Error Retrieving Weather"                                                                  message:[NSString stringWithFormat:@"%@",error]                                                                 delegate:nil                                                        cancelButtonTitle:@"OK" otherButtonTitles:nil];                     [av show];                                      }         ];    }    else if (buttonIndex==1){        NSURL *baseURL = [NSURL URLWithString:[NSString stringWithFormat:BaseURLString]];        NSDictionary *parameters = [NSDictionary dictionaryWithObject:@"json" forKey:@"format"];                AFHTTPClient *client = [[AFHTTPClient alloc] initWithBaseURL:baseURL];        [client registerHTTPOperationClass:[AFJSONRequestOperation class]];        [client setDefaultHeader:@"Accept" value:@"application/json"];                [client getPath:@"weather.php"             parameters:parameters                success:^(AFHTTPRequestOperation *operation, id responseObject) {                    self.weather = responseObject;                    self.title = @"HTTP GET";                    [self.tableView reloadData];                }                failure:^(AFHTTPRequestOperation *operation, NSError *error) {                    UIAlertView *av = [[UIAlertView alloc] initWithTitle:@"Error Retrieving Weather"                                                                 message:[NSString stringWithFormat:@"%@",error]                                                                delegate:nil                                                       cancelButtonTitle:@"OK" otherButtonTitles:nil];                    [av show];                                    }         ];    }}

1. 构建一个baseURL，以及一个参数字典，并将这两个变量传给AFHTTPClient.
2. 将AFJSONRequestOperation注册为HTTP的操作, 这样就可以跟之前的示例一样，可以获得解析好的JSON数据。
3. 做了一个GET请求，这个请求有一对block：success和failure。
4. POST请求跟GET一样。

 

上传一个文件

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];[operation setUploadProgressBlock:^(NSUInteger bytesWritten, long long totalBytesWritten, long long totalBytesExpectedToWrite) {    NSLog(@"Sent %lld of %lld bytes", totalBytesWritten, totalBytesExpectedToWrite);}];[httpClient enqueueHTTPRequestOperation:operation];
     

下载一个文件

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];

 

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