之前测试功能写过一次，因为代码忘记保存，导致真正用到的时候怎么也想不起来当初怎么写的了，复现后还是写个文章记录一下，省的下次再忘记。

php后端

/**
 * 图片保存到本地
 */
public function uploadLocalImage()
{
    try {
        $img = $this->_request->file('img');
        if (empty($img)) {
            throw new Exception('缺少图片参数');
        }
        $writeDir = "images/".date('Ymd');
        $dir = "D:/phpstudy_pro/WWW/vkm_locarun_dist/dist/".$writeDir;
        //$dir = "local_run/" . date('Ymd'); //linux调试地址
        if (!file_exists($dir)) {
            mkdir($dir, 0777, true);
        }
        if (substr($img->getMimeType(), -3) == 'bmp') {
            $fileName = UtilService::createOrderNo() . '.bmp';
        }else{
            $fileName = UtilService::createOrderNo() . '.jpg';
        }
        $imgContent = file_get_contents($img);
        file_put_contents($dir . '/' . $fileName, $imgContent);
        $localhostImg = env('CLIENT_URL') . $writeDir . '/' . $fileName;
        //http://127.0.0.1:8000/xxx/20231016/xxx.jpg 读取方式
        $this->returnSuccess($localhostImg);
    } catch (Exception $e) {
        $this->returnFault($e->getMessage());
    }
}

Unity C#

/// <summary>
/// 上传文件到服务器
/// </summary>
/// <param name="filePaths">文件路径</param>
void UploadToLocalServer(string[] filePaths)
{
    int count = filePaths.Length;
    urls = new string[count];
    isUploaded = new bool[count];

    string filePath;
    //文件命为上传OSS时的key
    for (int i = 0; i < count; i++)
    {
        int current = i;
        filePath = filePaths[current];
        if (File.Exists(filePath))
        {
            File.SetAttributes(filePath, FileAttributes.Normal);
            StartCoroutine(UploadToLocal(filePath, current));
        }
        else
        {
            urls[current] = "none";
        }
    }
}
IEnumerator UploadToLocal(string filePath, int index)
{
    byte[] fileByte = File.ReadAllBytes(filePath);
    WWWForm form = new WWWForm();
    //根据自己上传的文件修改格式,img是接口请求json参数的key, 
    //最后一个参数是图片的mimeType, 因为上传的图片有jpg、png、bmp几种格式，此处取文件后缀和image组合字符串作为mimeType
    form.AddBinaryData("img", fileByte, Path.GetFileName(filePath), $"image/{Path.GetExtension(filePath)}");

    Helper.Log($"{Config.SystemConfig.sendHost}/uploadLocalImage");
    using (UnityWebRequest www = UnityWebRequest.Post($"{Config.SystemConfig.sendHost}/uploadLocalImage", form))
    {
        yield return www.SendWebRequest();

        if (www.result == UnityWebRequest.Result.ConnectionError || www.result == UnityWebRequest.Result.ProtocolError)
        {
            urls[index] = "error";
            Helper.LogError($"[ERROR] {filePath}, msg: {www.error}");
        }
        else
        {
            string text = www.downloadHandler.text;
            //Helper.Log("服务器返回值" + text);

            JObject json = JObject.Parse(text);
            if (json["msg"].ToString().Equals("success"))
            {
                urls[index] = json["data"].ToString();
                Helper.Log($"[SUCCESS] {urls[index]}");
            }
            else
            {
                urls[index] = "error";
                Helper.LogError($"[ERROR] {filePath}, msg: {text}");
            }
            isUploaded[index] = true;
        }
    }
}

搞定。