NSString *str=[NSString stringWithFormat:@"https://alpha-api.app.net/stream/0/posts/stream/global"];
NSURL *url = [NSURL URLWithString:[str stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
// 从URL获取json数据
AFJSONRequestOperation *operation1 = [AFJSONRequestOperation JSONRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, NSDictionary* JSON) {
NSLog(@"获取到的数据为：%@",JSON);
} failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id data) {
NSLog(@"发生错误！%@",error);
}];
[operation1 start];
第二种方法，利用AFHTTPRequestOperation 先获取到字符串形式的数据，然后转换成json格式，将NSString格式的数据转换成json数据，利用IOS5自带的json解析方法：
NSString *str=[NSString stringWithFormat:@"https://alpha-api.app.net/stream/0/posts/stream/global"];
NSURL *url = [NSURL URLWithString:[str stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc]initWithRequest:request];
[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, idresponseObject) {
NSString *html = operation.responseString;
NSData* data=[html dataUsingEncoding:NSUTF8StringEncoding];
id dict=[NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
NSLog(@"获取到的数据为：%@",dict);
}failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(@"发生错误！%@",error);
}];
NSOperationQueue *queue = [[NSOperationQueue alloc] init];
[queue addOperation:operation];
如果发生Error Domain=NSURLErrorDomain Code=-1000 "bad URL" UserInfo=0x14defc80 {NSUnderlyingError=0x14deea10 "bad URL", NSLocalizedDescription=bad URL这个错误，请检查URL编码格式。有没有进行stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding
如何通过URL获取图片
异步获取图片，通过队列实现，而且图片会有缓存，在下次请求相同的链接时，系统会自动调用缓存，而不从网上请求数据。
UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0.0f, 100.0f, 100.0f, 100.0f)];
[imageView setImageWithURL:[NSURL URLWithString:@"http://i.imgur.com/r4uwx.jpg"]placeholderImage:[UIImage imageNamed:@"placeholder-avatar"]];
[self.view addSubview:imageView];
上面的方法是官方提供的，还有一种方法，
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;
} failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error) {
NSLog(@"Error %@",error);
}];
[operation start];
如果使用第一种URLWithString： placeholderImage：会有更多的细节处理，其实实现还是通过AFImageRequestOperation处理，可以点击URLWithString： placeholderImage：方法进去看一下就一目了然了。所以我觉得还是用第一种好。
如何通过URL获取plist文件
通过url获取plist文件的内容，用的很少，这个方法在官方提供的方法里面没有
NSString *weatherUrl = @"http://www.calinks.com.cn/buick/kls/Buickhousekeeper.plist";
NSURL *url = [NSURL URLWithString:[weatherUrl stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
[AFPropertyListRequestOperation addAcceptableContentTypes:[NSSet setWithObject:@"text/plain"]];
AFPropertyListRequestOperation *operation = [AFPropertyListRequestOperation propertyListRequestOperationWithRequest:request success:^(NSURLRequest *request,NSHTTPURLResponse *response, id propertyList) {
NSLog(@"%@",(NSDictionary *)propertyList);
}failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, idpropertyList) {
NSLog(@"%@",error);
}];
[operation start];
如果稍不留神，可能就出现Error Domain=AFNetworkingErrorDomain Code=-1016 "Expected content type {(
"application/x-plist"
)}, got text/plain" UserInfo=0x16e91ce0 {NSLocalizedRecoverySuggestion=
...
...
, AFNetworkingOperationFailingURLRequestErrorKey= { }, NSErrorFailingURLKey=, NSLocalizedDescription=Expected content type {(
"application/x-plist"
)}, got text/plain, AFNetworkingOperationFailinponseErrorKey= { URL: } { status code: 200, headers {
"Accept-Ranges" = bytes;
Connection = "keep-alive";
"Content-Length" = 974;
"Content-Type" = "text/plain";
Date = "Sat, 25 Jan 2014 07:29:26 GMT";
Etag = ""1014c2-3ce-4ee63e1c80e00"";
"Last-Modified" = "Wed, 25 Dec 2013 23:04:24 GMT";
Server = "nginx/1.4.2";
} }}
可能还会出现乱码，解决办法就是[AFPropertyListRequestOperation addAcceptableContentTypes:[NSSet setWithObject:@"text/plain"]];
