- (void)checkHTTPEnable {
    NSDictionary * ref = (__bridge NSDictionary *)CFNetworkCopySystemProxySettings();
    BOOL enable = [[ref objectForKey:@"HTTPEnable"] boolValue];
    if (enable) {
        NSLog(@"开启了代理");
    }else {
        NSLog(@"没开代理");
    }
}