无法提取大文件的元数据属性答案

【问题标题】：Cant extract metadata properties of large files无法提取大文件的元数据属性
【发布时间】：2021-11-21 09:02:33
【问题描述】：

我有一个大约 200MB 的 RVT 文件。当我使用 forge SDK (ObjectsApi.UploadObjectAsync()) 上传对象时，我多次收到超时错误，但后来不知何故上传了对象并提取了清单。

但是，在提取每张纸的modelViewMetadataProperties 时，它抛出了URN is too big to extract 错误，我无法处理它。

大文件如何上传对象并顺利提取modelViewMetadataProperties？

SDK版本：Assembly Autodesk.Forge, Version=1.9.0.0

【问题讨论】：

【解决方案1】：

要上传大文件，我建议您改用ObjectApi#UploadChunk。这是一个演示如何使用它的示例：https://github.com/yiskang/ForgeResumableUploadProgressDemo/blob/master/ForgeResumableUploadProgressDemo/Program.cs#L93

关于属性问题，请按照Alex的建议添加forceget参数并将其设置为true。这是它的declaration：

/// <summary>
/// 
/// </summary>
/// <remarks>
/// Returns a list of properties for each object in an object tree. Properties are returned according to object ID and do not follow a hierarchical structure.  The following image displays a typical list of properties for a Revit object:  ![](https://developer.doc.autodesk.com/bPlouYTd/7/_images/Properties.png)  To call this endpoint you need to first call the [GET {urn}/metadata](https://developer.autodesk.com/en/docs/model-derivative/v2/reference/http/urn-metadata-GET) endpoint, which returns a list of model view (metadata) IDs for a design input model. Select a model view (metadata) ID to use when calling the Get Properties endpoint.  Note that you can only get properties from a design input file that was previously translated into an SVF file. 
/// </remarks>
/// <exception cref="Autodesk.Forge.Client.ApiException">Thrown when fails to make API call</exception>
/// <param name="urn">The Base64 (URL Safe) encoded design URN </param>
/// <param name="guid">Unique model view ID. Call [GET {urn}/metadata](https://developer.autodesk.com/en/docs/model-derivative/v2/reference/http/urn-metadata-GET) to get the ID </param>
/// <param name="acceptEncoding">If specified with &#x60;gzip&#x60; or &#x60;*&#x60;, content will be compressed and returned in a GZIP format.  (optional)</param>
/// <param name="objectid">Object id which you want to query properties for.</param>
/// <param name="xAdsForce">If true - force retrieve the object tree even though it failed to be retrieved or got timeout (got 404 with error message) previously.</param>
/// <param name="forceget">If true - To force get the large resource even if it exceeded the expected maximum length (20 MB).</param>
/// <returns>Metadata</returns>
/*Metadata*/
dynamic GetModelviewProperties (string urn, string guid, string acceptEncoding = null, List<int> objectIds = null, bool xAdsForce = false, bool forceget = false);

下面是它的用法示例：

derivativeApi.GetModelviewProperties( urn, guid, null, null, false, true );

【讨论】：

【解决方案2】：

对于超时错误，此链接可能会有所帮助How does the UploadObjectAsync() method work?

关于元数据属性，文档说如果资源超过20mb，可以使用forceget参数查询true。该选项应该在 SDK 方法中可用。 URN Metadata Get Properties

【讨论】：