- (void)loadView {

 NSURLConnection *hc=nil;

@try{ NSURL *url=[NSURL URLWithString:@​http://218.206.70.212/SingleDemo/file/480/soumoneyhaidaotuan_1_10001000.dmh">​http://218.206.70.212/SingleDemo/file/480/soumoneyhaidaotuan_1_10001000.dmh​​];


NSMutableURLRequest* request=[NSMutableURLRequest requestWithURL:url];

 [request setValue:@"bytes=200 - 1200" forHTTPHeaderField:@"Range"];

//清空缓存(如果不加这一行,重复调用的时候总显示第一次的数据)

[request setCachePolicy:NSURLRequestReloadIgnoringLocalCacheData];

//这个是同步网络的调用方法

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

//nsdata换成char  打印读出来的数据

char* bu=[returnData bytes];

for (int i=0; i<[returnData  length];i++){

NSLog(@"打印数据:%d",bu[i]);


//异步调用方法

//hc=[NSURLConnection sendSynchronousRequest:request returningResponse:nil err:nil];

//[hc start];

if (hc) {

网络连接好了

}

}

以下方法全是异步时所调用的方法

- (void)connection:(NSURLConnection*)connection didReceiveResponse:

(NSHTTPURLResponse*)response {

//response saved so that status Codes can be checked later

    _response = [response retain];

    NSDictionary* headers = [response allHeaderFields];

    int contentLength = [[headers objectForKey:@"Content-Length"] intValue];


    //append the responseData used in connectionDidFinishLoading:

    _responseData = [[NSMutableData alloc] initWithCapacity:contentLength];

}

//获取数据

- (void)connection:(NSURLConnection*)connection didReceiveData:(NSData*)data {

[_responseData appendData:data];

}

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *error {​​NSLog(@"Connection​​ failed: %@", [error description]);}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {

[hc release];

}