Unity集成ChatGPT异常：请求返回随机无关响应（附C#代码）

问题描述 #

在Unity项目中用C#集成ChatGPT功能，已完成请求/响应的JSON封装类，能成功发送请求并获取响应，但返回内容完全无关。例如询问What is a verb?，得到的却是关于成功播客影响因素的回答。

相关代码 #

请求类 #

namespace OpenAIAPIManagement
{
    [Serializable]
    public class OpenAIAPIRequest
    {
        public string model = "gpt-3.5-turbo";
        public Message[] messages;
        public float temperature = 0.5f;
        public int max_tokens = 50;
        public float top_p = 1f;
        public float presence_penalty = 0f;
        public float frequency_penalty = 0f;

        public OpenAIAPIRequest(string model_, Message[] messages_, float temperature_, int max_tokens_, float top_p_, float presence_penalty_, float frequency_penalty_)
        {
            this.model = model_;
            this.messages = messages_;
            this.temperature = temperature_;
            this.max_tokens = max_tokens_;
            this.top_p = top_p_;
            this.presence_penalty = presence_penalty_;
            this.frequency_penalty = frequency_penalty_;
        }
    }

    [Serializable]
    public class Message
    {
        public string role = "user";
        public string content = "What is your purpose?";

        public Message(string role_, string content_)
        {
            this.role = role_;
            this.content = content_;
        }
    }
}

请求发送方法 #

public static async Task<Message> SendMessageToChatGPT(Message[] message, float temperature, int max_tokens, float top_p, float presence_penalty, float frequency_penalty)
{
    string request = OpenAIAPIManager.SerializeAPIRequest("gpt-4", message, temperature, max_tokens, top_p, presence_penalty, frequency_penalty);

    HttpClient client = new HttpClient();
    client.DefaultRequestHeaders.Add("Authorization", $"Bearer {_apiKey}");
    HttpResponseMessage response = await client.PostAsync(_apiURL, new StringContent(request, System.Text.Encoding.UTF8, "application/json"));

    if (response.IsSuccessStatusCode)
    {
        Message responseMessage = OpenAIAPIManager.DeserializeAPIResponse(await response.Content.ReadAsStringAsync()).choices[0].message;
        Debug.Log("ChatGPT: " + responseMessage.content);
        return await Task.FromResult<Message>(responseMessage);
    }
    else
    {
        return await Task.FromResult<Message>(new Message("Error", "Status" + response.StatusCode));
    }
}

输入字段处理逻辑 #

public async void ProcessMessageFromInputField()
{
    if (_userInput && !string.IsNullOrWhiteSpace(_userInput.text))
    {
        _chatData.Clear();
        _chatData.Add(_userInput.text + _userPostfix);
        PostMessageToContentPanel(_chatData[0]);
        _userInput.text = "";
        Message userMessage = new Message("user", _userInput.text);
        Message chatAgentResponse = await OpenAIAPIManager.SendMessageToChatGPT(new Message[]{userMessage}, 0.7f, 256, 1f, 0f, 0f);
        PostMessageToContentPanel(chatAgentResponse.content + _aiPostfix);
    }
}

排查关键点 #

• 输入字段处理逻辑错误：创建userMessage前已清空_userInput.text，导致发送给ChatGPT的是空内容。ChatGPT收到空请求时会返回训练数据中的随机内容，这是返回无关回答的核心原因。修正方法：先保存输入文本再清空输入框：

  string inputText = _userInput.text;
  _userInput.text = "";
  Message userMessage = new Message("user", inputText);
  

• 验证请求序列化结果：检查SerializeAPIRequest生成的JSON，确保messages数组内的用户消息内容是正确的提问文本，而非空值。
• 确认API端点正确性：_apiURL必须为ChatGPT对话接口https://api.openai.com/v1/chat/completions，若误用文本补全接口会导致异常响应。
• 检查模型权限：确认账号有权限使用gpt-4模型，无权限时会降级或返回非预期内容，可先切换为gpt-3.5-turbo测试。

内容的提问来源于stack exchange，提问作者Yakuman