F515249B-CC3F-4F22-B5EB-20D2B4F68EB1.png

错误示例：

    //1.创建一个网络路径
    NSURL *url = [NSURL URLWithString:urlString];
    // 2.创建一个网络请求
    NSURLRequest *request =[NSURLRequest requestWithURL:url];
    // 3.获得会话对象
    NSURLSession *session = [NSURLSession sharedSession];
    // 4.根据会话对象，创建一个Task任务
 NSURLSessionDataTask *sessionDataTask = [session dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
        NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse*)response;
        NSLog(@"从服务器获取到数据 %ld",(long)httpResponse.statusCode);
        /*对从服务器获取到的数据data进行相应的处理：*/
        NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:(NSJSONReadingMutableLeaves) error:nil];
        NSLog(@"%@",dict);
    }];
    // 5.最后一步，执行任务（resume也是继续执行）:
    [sessionDataTask resume];```
>正确示例

 ``` Nsstring*urlString=@"https://graph.facebook.com/debug_token?input_token=/*facebook return token*/&access_token=/*apptoken*/";```
  ###urlString=[urlString stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]];###
  ``` NSURL *url = [NSURL URLWithString:urlString];;```