/// <summary>
/// 下载消息内元素到指定文件路径（图片、视频、音频、文件）。
/// </summary>
/// <param name="downloadElemParam">下载的参数</param>
/// <param name="savePath">下载文件保存路径</param>
/// <param name="handler">下载成功与否的回调以及下载进度回调</param>
public static TIMResult IMMsgDownloadElemToPath(DownloadElemParam downloadElemParam, string savePath, MsgDownloadElemToPathDelgate handler = null)
{
var ptr = DelegateConverter.ConvertToIntPtr(handler);
return((TIMResult)TIMClientAPIDef.TIMMsgDownloadElemToPath(JsonConvert.SerializeObject(downloadElemParam), savePath, MsgDownloadElemToPathDelgateResultCallBack, ptr));
}