1、 同步GET请求
//第一步,创建URL
NSURL *url = [NSURL URLWithString:@ "http://api.hudong.com/iphonexml.do?type=focus-c" ];
//第二步,通过URL创建网络请求
NSURLRequest *request = [[NSURLRequest alloc]initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:10];
//NSURLRequest初始化方法第一个参数:请求访问路径,第二个参数:缓存协议,第三个参数:网络请求超时时间(秒)
其中缓存协议是个枚举类型包含:
NSURLRequestUseProtocolCachePolicy(基础策略)
NSURLRequestReloadIgnoringLocalCacheData(忽略本地缓存)
NSURLRequestReturnCacheDataElseLoad(首先使用缓存,如果没有本地缓存,才从原地址下载)
NSURLRequestReturnCacheDataDontLoad(使用本地缓存,从不下载,如果本地没有缓存,则请求失败,此策略多用于离线操作)
NSURLRequestReloadIgnoringLocalAndRemoteCacheData(无视任何缓存策略,无论是本地的还是远程的,总是从原地址重新下载)
NSURLRequestReloadRevalidatingCacheData(如果本地缓存是有效的则不下载,其他任何情况都从原地址重新下载)
//第三步,连接服务器
NSData *received = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
NSString *str = [[NSString alloc]initWithData:received encoding:NSUTF8StringEncoding];
NSLog(@ "%@" ,str);
2、同步POST请求
//第一步,创建URL
NSURL *url = [NSURL URLWithString:@ "http://api.hudong.com/iphonexml.do" ];
//第二步,创建请求
NSMutableURLRequest *request = [[NSMutableURLRequest alloc]initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:10];
[request setHTTPMethod:@ "POST" ]; //设置请求方式为POST,默认为GET
NSString *str = @ "type=focus-c" ; //设置参数
NSData *data = [str dataUsingEncoding:NSUTF8StringEncoding];
[request setHTTPBody:data];
//第三步,连接服务器
NSData *received = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
NSString *str1 = [[NSString alloc]initWithData:received encoding:NSUTF8StringEncoding];
NSLog(@ "%@" ,str1);
3、异步GET请求
//第一步,创建url
NSURL *url = [NSURL URLWithString:@ "http://api.hudong.com/iphonexml.do?type=focus-c" ];
//第二步,创建请求
NSURLRequest *request = [[NSURLRequest alloc]initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:10];
//第三步,连接服务器
NSURLConnection *connection = [[NSURLConnection alloc]initWithRequest:request delegate:self];
4、异步POST请求
//第一步,创建url
NSURL *url = [NSURL URLWithString:@ "http://api.hudong.com/iphonexml.do" ];
//第二步,创建请求
NSMutableURLRequest *request = [[NSMutableURLRequest alloc]initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:10];
[request setHTTPMethod:@ "POST" ];
NSString *str = @ "type=focus-c" ;
NSData *data = [str dataUsingEncoding:NSUTF8StringEncoding];
[request setHTTPBody:data];
//第三步,连接服务器
NSURLConnection *connection = [[NSURLConnection alloc]initWithRequest:request delegate:self];
5、异步请求的代理方法
//接收到服务器回应的时候调用此方法
- ( void )connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
NSHTTPURLResponse *res = (NSHTTPURLResponse *)response;
NSLog(@ "%@" ,[res allHeaderFields]);
self.receiveData = [NSMutableData data];
}
//接收到服务器传输数据的时候调用,此方法根据数据大小执行若干次
-( void )connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
[self.receiveData appendData:data];
}
//数据传完之后调用此方法
-( void )connectionDidFinishLoading:(NSURLConnection *)connection
{
NSString *receiveStr = [[NSString alloc]initWithData:self.receiveData encoding:NSUTF8StringEncoding];
NSLog(@ "%@" ,receiveStr);
}
//网络请求过程中,出现任何错误(断网,连接超时等)会进入此方法
-( void )connection:(NSURLConnection *)connection
didFailWithError:(NSError *)error
{
NSLog(@ "%@" ,[error localizedDescription]);
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