IOS 获取外网IP 及 GBK 转码 (UTF-8)

- (void)viewDidLoad

{

    [superviewDidLoad];

   NSURL *url = [NSURLURLWithString:@"http://fw.qq.com/ipaddress"];

    

   NSMutableURLRequest *request = [NSMutableURLRequestrequestWithURL:url];

    [request setHTTPMethod:@"GET"];

    [requestsetTimeoutInterval:8.0f];

    NSHTTPURLResponse *response;    

    

   //返回的是GBK编码

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

    if (200 == [response statusCode]) {

       //直接转,将会产生乱码或者字符串为空    NSUTF8StringEncoding

       NSString *temp1 = [[NSStringalloc] initWithData:returnDataencoding:NSUTF8StringEncoding];

       //                               NSASCIIStringEncoding

       NSString *temp2 = [[NSStringalloc] initWithData:returnDataencoding:NSASCIIStringEncoding];

       NSLog(@"---------temp1---%@",temp1);

       NSLog(@"---------temp2---%@",temp2);

       NSLog(@"-------------------------------------");

        

       // 一、 GBK编码 (通过CFStringCreateWithBytes转码)

       CFStringRef GBKCFstirng =CFStringCreateWithBytes(NULL,[returnDatabytes], [returnDatalength],kCFStringEncodingGB_18030_2000,false);

        NSString *gbkNSString1 = (NSString *)GBKCFstirng;

        NSLog(@"--gbkNSString1---%@",gbkNSString1);

        

       // 二、 GBK编码 (通过CFStringConvertEncodingToNSStringEncoding转码)

       NSStringEncoding nsEncoding =CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGB_18030_2000);  

        NSString *gbkNSString2 = [[NSString alloc] initWithData:returnData encoding:nsEncoding];  

        NSLog(@"--gbkNSString2---%@",gbkNSString2);

        

       NSLog(@"-------------------------------------");

        

       //转成NSUTF8StringEncoding的字符串

        NSData *tempdata = [gbkNSString1 dataUsingEncoding:NSUTF8StringEncoding];

       NSString *UTF8_NSString = [[NSStringalloc] initWithData:tempdataencoding:NSUTF8StringEncoding];

        NSLog(@"--UTF8_NSString--%@",UTF8_NSString);       

    }

}