同步和异步GET,POST请求
#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]);
}
