iPhone同步请求

同步请求的步骤:
1 初始化一个NSUrl对象url
2 使用url初始化NSURLRequest对象request 设置缓存策略为忽略缓存 缓存时间
3 使用NSURLConnection 发送请求request请求 并返回一个NSData对象

代码:
NSString* strURL = @"http://m.weather.com.cn/data/101180601.html";
NSURL* url = [NSURL URLWithString:strURL];
NSURLRequest* requent = [[NSURLRequest alloc]initWithURL:url cachePolicy:NSURLRequestReloadIgnoringCacheData timeoutInterval:60];
//cachePolicy缓存策略 NSURLRequestReloadIgnoringCacheData忽略缓存  timeoutInterval缓存时间超过60秒数据为nil
NSURLResponse* response = nil;
NSError* error = nil;
NSData* data1 = [NSURLConnection sendSynchronousRequest:requent returningResponse:&response error:&error];
NSString* str = [[NSString alloc]initWithData:data1 encoding:NSUTF8StringEncoding];
NSLog(@"str = %@",str);