NSString *IP = @"0.0.0.0";

    //http://61.4.185.48:81/g/（中国天气网的接口）

    NSURL *url = [NSURL URLWithString:@"http://61.4.185.48:81/g/"];

    NSURLRequest *request = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:1.0];

    

    NSURLResponse *response = nil;

    NSError *error = nil;

    NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];

    if (error) {

        NSLog(@"Failed to get WAN IP Address!\n%@", error);

    } else {

        NSString *responseStr = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

        IP = responseStr;

    }

    NSLog(@"%@",IP);

    return IP;