直接上代码
示例：
-（void）touchesBeGan:(NSSet *)touches withEvent:(UIEvent *)event
{
//1.url
NSURL *url = [NSURL URLWithString:@"http://m.baidu.com"]'
//2.request
NSURLRequest *request = [NSURLRequest requestWithURL:url];
//3.发送网络连接 获取二进制数据
[NSURLConnection sendAsynchronouRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response,NSData *data,NSError *connectionError){
//在开发http访问，通常会把返回的二进制数据变成字符串，以便于调试
NSString *html = [NSString alloc]initWithData:data encoding:NSUTF8StringEncoding
;
NSLog(@"%@",html);
}];
}