今天记录一下afn 请求参数要以body的方式传递给后台。下面是核心代码：

-(void)requestBody{
        //参数
        NSDictionary *params = @{@"key1":@"value1",@"key2":@"value2"};
        //参数转data
        NSData *dataBody = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
        //初始化请求 request
        NSMutableURLRequest *request = [[AFHTTPRequestSerializer serializer] requestWithMethod:@"POST" URLString:url parameters:nil error:nil];
        request.timeoutInterval = 60.f;
        //设置请求头格式
        [request setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
        [request setValue:@"application/json" forHTTPHeaderField:@"Accept"];
        //设置请求体 body
        [request setHTTPBody:dataBody];
        //初始化请求管理 manager
        AFURLSessionManager *manager = [[AFURLSessionManager alloc] initWithSessionConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration]];
        AFHTTPResponseSerializer *responseSerializer = [AFHTTPResponseSerializer serializer];
        responseSerializer.acceptableContentTypes = [NSSet setWithObjects:@"application/json", @"text/html", @"text/json", @"text/javascript", @"text/plain", @"application/javascript", nil];
        manager.responseSerializer = responseSerializer;
        //开始请求 resume（启动请求---很重要的一步，否则请求不启动）
        [[manager dataTaskWithRequest:request uploadProgress:^(NSProgress * _Nonnull uploadProgress) {
            
        } downloadProgress:^(NSProgress * _Nonnull downloadProgress) {
            
        } completionHandler:^(NSURLResponse * _Nonnull response, id  _Nullable responseObject, NSError * _Nullable error) {
            if (!error) {
                NSDictionary *jsonData = [NSJSONSerialization JSONObjectWithData:responseObject options:NSJSONReadingMutableLeaves error:nil];  //解析
                NSLog(@"%@",jsonData);
            } else {
                NSLog(@"：%@",error);
            }
        }] resume];
    }
    
    
    /**
     *  NSDictionary-->NSString(json形式的)
     */
    - (NSString*)convertToJSONData:(id)infoDict
    {
        NSError *error;
        NSData *jsonData = [NSJSONSerialization dataWithJSONObject:infoDict
                                                           options:NSJSONWritingPrettyPrinted
                                                             error:&error];
        NSString *jsonString = @"";
        if (!jsonData){
            NSLog(@"Got an error: %@", error);
        }else{
            jsonString = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
        }
        
        jsonString = [jsonString stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];  //去除掉首尾的空白字符和换行字符
        jsonString = [jsonString stringByReplacingOccurrencesOfString:@"\n" withString:@""];
        jsonString = [jsonString stringByReplacingOccurrencesOfString:@" " withString:@""];// 去掉空格
        //jsonString = [jsonString stringByReplacingOccurrencesOfString:@"\\" withString:@""];// 去掉斜杠
        return jsonString;
}