AFNetwork作用和用法详解

AFNetwork是一个轻量级的网络请求api类库。是以NSURLConnection, NSOperation和其他方法为基础的。

下面这个例子是用来处理json请求的：

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];

使用方法：

1.下载AFNetwork，点击下载

2.将文件夹名称为AFNetworking拖入到你的工程项目即可

常见问题：

1. AFNetworking作用都有哪些？

NSURLConnection提供了+sendAsynchronousRequest:queue:completionHandler:和+sendAsynchronousRequest:queue:completionHandler:
，但是AFNetworking提供了更好的功能

＊AFURLConnectionOperation和它的子类继承NSOperation的，允许请求被取消，暂停/恢复和由NSOperationQueue进行管理。

＊AFURLConnectionOperation也可以让你轻松得完成上传和下载，处理验证，监控上传和下载进度，控制的缓存。

＊AFHTTPRequestOperation和它得子类可以基于http状态和内容列下来区分是否成功请求了

＊AFNetworking可以将远程媒体数据类型（NSData）转化为可用的格式，比如如JSON，XML，图像和plist。

＊AFHTTPClient提供了一个方便的网络交互接口，包括默认头，身份验证，是否连接到网络，批量处理操作，查询字符串参数序列化，已经多种表单请求

＊的UIImageView+ AFNetworking增加了一个方便的方法来异步加载图像。

2. AFNetworking是否支持缓存？

可以，NSURLCache及其子类提供了很多高级接口用于处理缓存

如果你想将缓存存储再磁盘，推荐使用SDURLCache

3.如何使用AFNetworking上传一个文件？

NSData *imageData = UIImagePNGRepresentation(image);

NSURLRequest *request = [client multipartFormRequestWithMethod:@"POST" path:@"/upload" parameters:nil
constructingBodyWithBlock: ^(id formData) {

[formData appendPartWithFileData:imageData mimeType:@"image/png" name:@"avatar"];

}];

4.如何使用AFNetworking下载一个文件？

先创建一个AFURLConnectionOperation对象，然后再使用它的属性outputStream进行处理

operation.outputStream = [NSOutputStream outputStreamToFileAtPath:@"download.zip" append:NO];

5.如何解决：SystemConfiguration framework not found in project

请导入：

#import

#import

6.当应用程序退出时，如何保持持续的请求？

AFURLConnectionOperation有一个叫setShouldExecuteAsBackgroundTaskWithExpirationHandler:的方法用于处理在应用程序进入后台后，进行持续的请求

[self setShouldExecuteAsBackgroundTaskWithExpirationHandler:^{

}];

一些实例：

1.XML 请求

NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://api.flickr.com/services/rest/?method=flickr.groups.browse&api_key=b6300e17ad3c506e706cb0072175d047&cat_id=34427469792@N01&format=rest"]];

AFXMLRequestOperation *operation = [AFXMLRequestOperation XMLParserRequestOperationWithRequest:request
success:^(NSURLRequest *request, NSHTTPURLResponse *response, NSXMLParser *XMLParser) {

XMLParser.delegate = self;

[XMLParser parse];

} failure:nil];

[operation start];

2.图片请求：

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.图片上传处理，监测上传状态：

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 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.在线流媒体请求

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];

from :http://www.zpluz.com/forum.php?mod=viewthread&tid=2052