iOS 使用AFNetworking上传和接收字符串

在项目中有个需求，请求数据使用DES加密，加密之后使用AFNetworking上传和接收字符串，需要解决不能上传和接收字符串的问题

[manager.requestSerializer setQueryStringSerializationWithBlock:^NSString * _Nonnull(NSURLRequest * _Nonnull request, id  _Nonnull parameters, NSError * _Nullable __autoreleasing * _Nullable error) {
     //在这里面对parameters进行处理
     return 处理后的参数;
}];

以上方法是我在网上看到的，但是可能姿势不对，不管用。
在网上看了很多攻略，记录一下自己觉得最直观的方法，但是这个方法有一个缺点：

如果你是用Cocoapods管理，那么每次更新就需要修改一次

代码

AFURLRequestSerialization.m

#pragma mark - AFURLRequestSerialization

- (NSURLRequest *)requestBySerializingRequest:(NSURLRequest *)request
                               withParameters:(id)parameters
                                        error:(NSError *__autoreleasing *)error
{
    NSParameterAssert(request);

    if ([self.HTTPMethodsEncodingParametersInURI containsObject:[[request HTTPMethod] uppercaseString]]) {
        return [super requestBySerializingRequest:request withParameters:parameters error:error];
    }

    NSMutableURLRequest *mutableRequest = [request mutableCopy];

    [self.HTTPRequestHeaders enumerateKeysAndObjectsUsingBlock:^(id field, id value, BOOL * __unused stop) {
        if (![request valueForHTTPHeaderField:field]) {
            [mutableRequest setValue:value forHTTPHeaderField:field];
        }
    }];

    if (parameters) {
        if (![mutableRequest valueForHTTPHeaderField:@"Content-Type"]) {
            [mutableRequest setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
        }
        //判断并且处理字符串
        if ([parameters isKindOfClass:[NSString class]]) {
            [mutableRequest setHTTPBody:[parameters dataUsingEncoding:NSUTF8StringEncoding]];
        }else{
            //这种处理方式并不严谨，还是需要按照下面注释的源码来处理
            [mutableRequest setHTTPBody:[NSJSONSerialization dataWithJSONObject:parameters options:self.writingOptions error:error]];
        }
//        if (![NSJSONSerialization isValidJSONObject:parameters]) {
//            if (error) {
//                NSDictionary *userInfo = @{NSLocalizedFailureReasonErrorKey: NSLocalizedStringFromTable(@"The `parameters` argument is not valid JSON.", @"AFNetworking", nil)};
//                *error = [[NSError alloc] initWithDomain:AFURLRequestSerializationErrorDomain code:NSURLErrorCannotDecodeContentData userInfo:userInfo];
//            }
//            return nil;
//        }
//
//        NSData *jsonData = [NSJSONSerialization dataWithJSONObject:parameters options:self.writingOptions error:error];
//
//        if (!jsonData) {
//            return nil;
//        }
//
//        [mutableRequest setHTTPBody:jsonData];
    }

    return mutableRequest;
}

接收字符串：

AFURLResponseSerialization.m

//添加 "text/plain"
self.acceptableContentTypes = [NSSet setWithObjects:@"application/json", @"text/json", @"text/javascript",@"text/plain", nil];

#pragma mark - AFURLResponseSerialization

- (id)responseObjectForResponse:(NSURLResponse *)response
                           data:(NSData *)data
                          error:(NSError *__autoreleasing *)error
{
    if (![self validateResponse:(NSHTTPURLResponse *)response data:data error:error]) {
        if (!error || AFErrorOrUnderlyingErrorHasCodeInDomain(*error, NSURLErrorCannotDecodeContentData, AFURLResponseSerializationErrorDomain)) {
            return nil;
        }
    }

    // Workaround for behavior of Rails to return a single space for `head :ok` (a workaround for a bug in Safari), which is not interpreted as valid input by NSJSONSerialization.
    // See https://github.com/rails/rails/issues/1742
    BOOL isSpace = [data isEqualToData:[NSData dataWithBytes:" " length:1]];
    
    if (data.length == 0 || isSpace) {
        return nil;
    }
    
    NSError *serializationError = nil;
    
    id responseObject = [NSJSONSerialization JSONObjectWithData:data options:self.readingOptions error:&serializationError];
    //添加字符串的处理
    if (!responseObject && [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]) {
        return [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    }
    
    if (!responseObject)
    {
        if (error) {
            *error = AFErrorWithUnderlyingError(serializationError, *error);
        }
        return nil;
    }
    
    if (self.removesKeysWithNullValues) {
        return AFJSONObjectByRemovingKeysWithNullValues(responseObject, self.readingOptions);
    }

    return responseObject;
}

仅记录开发中的问题