http网络库是集XML解析,Json解析,网络图片下载,plist解析,数据流请求操作,上传,下载,缓存等网络众多功能于一身的强大的类库。最新版本支持session,xctool单元测试。网络获取数据一直是手机软件的重中之重,如果处理的不好,会造成很差的用户体验。随着ASIHTTPRequest的停止更新,更换网络库是必然的事情,AFNetworking就是很好的替代品。而且都是轻量级,不要担心加入太多库会多软件性能有影响。
1.为什么用第三方网络库?先说如果不用网络库,我曾有一次觉得什么都用苹果原生的好,XML解析用苹果自带的委托,下载图片自己写,如果你也有跟我一样的经历,那你会发现自己管理起来很复杂,很容易出错。而且性能不好。如果你是一个追求完美的人,那就放下你的固执,就如当初的我一样,尝试一下网络库吧。
2.为什么要用AFNetworking?第一点,它有人更新和维护,而且目前使用者很多,第二点,还是使用者很多,那么他的资料,文档,demo就多,很好找遇到问题好解决。如果不用AFNetworking,还有一种MKNetworkKit也不错,不妨一试。
NSString *str=[NSString stringWithFormat:@"https://alpha-api./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./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, id responseObject) {
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./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./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./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, id propertyList) {
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"]];
如何通过URL获取XML数据
xml解析使用AFXMLRequestOperation,需要实现苹果自带的NSXMLParserDelegate委托方法,XML中有一些不需要的协议格式内容,所以就不能像json那样解析,还得实现委托。我之前有想过能否所有的XML链接用一个类处理,而且跟服务端做了沟通,结果很不方便,效果不好。XML大多标签不同,格式也不固定,所以就有问题,使用json就要方便的多。
第一步;在.h文件中加入委托NSXMLParserDelegate
第二步;在.m文件方法中加入代码
NSURL
*url = [NSURL
URLWithString:@"http://113.106.90.22:5244/sshopinfo"];
NSURLRequest *request = [NSURLRequest
requestWithURL:url];
AFXMLRequestOperation *operation =
[AFXMLRequestOperation
XMLParserRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, NSXMLParser *XMLParser) {
XMLParser.delegate = self;
[XMLParser
setShouldProcessNamespaces:YES];
[XMLParser parse];
}failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, NSXMLParser *XMLParser) {
NSLog(@"%@",error);
}];
[operation start];
第三步;在.m文件中实现委托方法
//在文档开始的时候触发
-(void)parserDidStartDocument:(NSXMLParser *)parser{
NSLog(@"解析开始!");
}
//解析起始标记
- (void)parser:(NSXMLParser *)parser
didStartElement:(NSString
*)elementName namespaceURI:(NSString *)namespaceURI
qualifiedName:(NSString *)qName
attributes:(NSDictionary
*)attributeDict{
NSLog(@"标记:%@",elementName);
}
//解析文本节点
- (void)parser:(NSXMLParser *)parser
foundCharacters:(NSString
*)string{
NSLog(@"值:%@",string);
}
//解析结束标记
- (void)parser:(NSXMLParser *)parser
didEndElement:(NSString
*)elementName namespaceURI:(NSString *)namespaceURI
qualifiedName:(NSString
*)qName{
NSLog(@"结束标记:%@",elementName);
}
//文档结束时触发
-(void)
parserDidEndDocument:(NSXMLParser *)parser{
NSLog(@"解析结束!");
}
运行的结果:
如何使用AFHTTPClient进行web service操作
BaseURLString =
@"http://www./downloads/weather_sample/";
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:@"text/html"];
[client postPath:@"weather.php" parameters:parameters success:^(AFHTTPRequestOperation *operation,
id responseObject) {
NSString* newStr = [[NSString alloc] initWithData:responseObject encoding:NSUTF8StringEncoding];
NSLog(@"POST请求:%@",newStr);
}failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(@"%@",error);
}];
[client getPath:@"weather.php" parameters:parameters success:^(AFHTTPRequestOperation *operation,
id responseObject) {
NSString* newStr = [[NSString alloc] initWithData:responseObject encoding:NSUTF8StringEncoding];
NSLog(@"GET请求:%@",newStr);
}failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(@"%@",error);
}];
运行结果: