AFNetworking 怎么解析非 json 的 字符串 返回数据

在其源码里面增加代码，位置为：AFN>Serialization>AFURLResponseSerialization.m>-responseObjectForResponse:data:error:

#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];

>这段代码
    if (!responseObject) {
        responseObject = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    }
>这段代码
    
    if (!responseObject)
    {
        if (error) {
            *error = AFErrorWithUnderlyingError(serializationError, *error);
        }
        return nil;
    }
    
    if (self.removesKeysWithNullValues) {
        return AFJSONObjectByRemovingKeysWithNullValues(responseObject, self.readingOptions);
    }

    return responseObject;
}