get方法:（在代码中可以直接看到请求内容 NSString *str = @"http://api.hudong.com/iphonexml.do?type=focus-c"; focus-c是接受服务器上的命令）
同步请求:
1 //请求数据, 把数据放在textView上 2 NSString *str = @"http://api.hudong.com/iphonexml.do?type=focus-c"; 3 NSURL *url = [NSURL URLWithString:str]; 4 NSMutableURLRequest *req = [[NSMutableURLRequest alloc]initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:6]; 5 NSData *data = [NSURLConnection sendSynchronousRequest:req returningResponse:nil error:nil]; 6 NSString *str1 = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding]; 7 self.textView.text = str1;
异步请求:
1、签代理 （NSURLConnectionDataDelegate）,实例化URL
1 //请求数据, 把数据放在textView上 2 NSString *str = @"http://api.hudong.com/iphonexml.do?type=focus-c"; 3 NSURL *url = [NSURL URLWithString:str]; 4 NSMutableURLRequest *req = [[NSMutableURLRequest alloc]initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:3]; 5 [[NSURLConnection alloc]initWithRequest:req delegate:self];
2、实现基本的三个代理方法 (timeoutInterval 不能设置太小 否则内容加载不出来)
发出请求-->收到服务器响应-->接收到服务器数据-->服务器数据加载完成
还要实现发生错误时的代理方法（timeoutInterval 不能设置太小 否则内容加载不出来，下面方法就是出现错误时候调用）：
post方法:（看不到请求内容，保密性较好）
NSString *str = @"http://api.hudong.com/iphonexml.do";
同步请求：
1 NSString *str = @"http://api.hudong.com/iphonexml.do"; 2 NSURL *url = [NSURL URLWithString:str]; 3 NSMutableURLRequest *requ = [[NSMutableURLRequest alloc]initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:3]; 4 [requ setHTTPMethod:@"POST"]; 5 //[requ setTimeoutInterval:3]; 6 //[requ setURL:url]; 7 NSString *str1 = @"type=focus-c"; 8 NSData *data = [str1 dataUsingEncoding:NSUTF8StringEncoding]; 9 [requ setHTTPBody:data]; 10 NSData *dta1 = [NSURLConnection sendSynchronousRequest:requ returningResponse:nil error:nil]; 11 NSString *str2 = [[NSString alloc]initWithData:dta1 encoding:NSUTF8StringEncoding]; 12 self.textView.text = str2;
异步请求：
1 NSString *str = @"http://api.hudong.com/iphonexml.do"; 2 NSURL *url = [NSURL URLWithString:str]; 3 NSMutableURLRequest *requ = [[NSMutableURLRequest alloc] init]; 4 [requ setURL:url]; 5 [requ setTimeoutInterval:3]; 6 [requ setHTTPMethod:@"POST"]; 7 NSString *str1 = @"type=focus-c"; 8 NSData *data = [str1 dataUsingEncoding:NSUTF8StringEncoding]; 9 [requ setHTTPBody:data]; 10 [[NSURLConnection alloc]initWithRequest:requ delegate:self];