#pragma mark -同步GET请求

- (IBAction)synGet:(id)sender

{

//第一步，创建URL

NSURL *url=[[NSURL alloc]initWithString:@"http://www.weather.com.cn/data/sk/101010100.html"];

//第二步，通过URL创建网络请求

NSURLRequest *request=[[NSURLRequest alloc]initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60];

//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

NSURLResponse *response=nil;

NSError *error=nil;

NSData *received=[NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];

NSString *str=[[NSString alloc]initWithData:received encoding:NSUTF8StringEncoding];

NSLog(@"%@",str);

}

#pragma mark -同步POST请求

- (IBAction)synPost:(id)sender

{

NSURL *url=[NSURL URLWithString:@"http://api.hudong.com/iphonexml.do"];

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];

NSData *received=[NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];

NSString *str1=[[NSString alloc]initWithData:received encoding:NSUTF8StringEncoding];

NSLog(@"%@",str1);

}

//异步GET请求

-(void)a{

NSURL *url=[NSURL URLWithString:@"http://api.hudong.com/iphonexml.do?type=focus-c"];

NSURLRequest *request = [[NSURLRequest alloc]initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:10];

NSURLConnection *connection = [[NSURLConnection alloc]initWithRequest:request delegate:self];

}

//异步POST请求

-(void)b{

NSURL *url = [NSURL URLWithString:@"http://api.hudong.com/iphonexml.do"];

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];

NSURLConnection *connection = [[NSURLConnection alloc]initWithRequest:request delegate:self];

}

//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]);

}