问题描述
我正在尝试编写一个工具（在 C# 中）从 VersionOne 资产（故事/缺陷）中读取嵌入的图像并将它们存储在本地（以便以后能够将它们迁移到另一个地方）。
我找到了这个链接以供参考： https://community.versionone.com/Digital.ai_Agility_Integrations/Developer_Library/Get_an_SDK/.NET_SDK/Working_with_Attachments_and_Images
这样我就可以成功读取附件，但是嵌入的图像仍然是一个问题。
我目前对此的尝试是这样的：
public string StoreActiveV1ItemEmbeddedImages(PrimaryWorkitem v1Item,string targetPath,out int countStored)
{
string result = string.Empty;
countStored = 0;
if (v1Item == null) return "Error: No V1 item given to StoreActiveV1ItemEmbeddedImages!";
string filePath = targetPath;
if (!filePath.EndsWith("\\")) filePath += "\\";
if (!Directory.Exists(filePath)) return "Error: Given path '" + filePath + "' does not exist!";
IServices services = v1Instance.apiclient.Services;
Imetamodel metamodel = v1Instance.apiclient.metamodel;
IAttachments attachments = v1Instance.apiclient.Attachments;
Oid itemOid = services.Getoid(v1Item.ID.Token);
IAssetType assetType = metamodel.GetAssetType("EmbeddedImage");
var query = new Query(assetType);
IAttributeDeFinition contentAttribute = assetType.GetAttributeDeFinition("Content");
IAttributeDeFinition contentTypeAttribute = assetType.GetAttributeDeFinition("ContentType");
IAttributeDeFinition assetAttribute = assetType.GetAttributeDeFinition("Asset");
query.Selection.Add(contentAttribute);
query.Selection.Add(contentTypeAttribute);
query.Selection.Add(assetAttribute);
FilterTerm term = new FilterTerm(assetAttribute);
term.Equal(itemOid.Momentless);
query.Filter = term;
QueryResult queryResult = services.Retrieve(query);
foreach (Asset attachment in queryResult.Assets)
{
VersionOne.SDK.apiclient.Attribute attribute = attachment.GetAttribute(contentTypeAttribute);
string mimeType = "image/png";
if (attribute != null)
{
mimeType = attribute.Value.ToString();
}
string extension = MimeTypestringToExtensionForImages(mimeType);
string fileName = (countStored + 1) + "_" + extension;
string attachmentID = attachment.Oid.Key.ToString();
string content = attachment.GetAttribute(contentAttribute).Value.ToString();
using (var fileStream = File.Create(filePath + "v1_img_" + fileName))
{
using (Stream blob = attachments.GetReadStream(content))
{
blob.copyTo(fileStream);
}
countStored++;
}
}
return result;
}
我在这一行遇到问题
using (Stream blob = attachments.GetReadStream(content))
服务器以这样的 404 响应： “远程服务器返回错误：(404) 未找到。'”
下面可以看到调试器中的值：
我已经对内容 (/VersionOne/embedded.img/2041732) 和附件 ID (2041732) 进行了尝试，但都导致了相同的错误。
我应该使用什么来查找数据，或者我是否理解这个更严重错误并需要采用不同的方法？
任何帮助将不胜感激！
解决方法
我想我找到了答案。不确定这是否是最好的答案，甚至是好的答案，但至少目前看来对我来说已经足够了。
“内容”是可以附加到 VersionOne 基本 URL 的路径，它们一起指向可以下载嵌入图像数据的位置。
所以我修改后的代码现在看起来像这样：
public string StoreActiveV1ItemEmbeddedImages(PrimaryWorkitem v1Item,string targetPath,out int countStored)
{
string result = string.Empty;
countStored = 0;
if (v1Item == null) return "Error: No V1 item given to StoreActiveV1ItemEmbeddedImages!";
string filePath = targetPath;
if (!filePath.EndsWith("\\")) filePath += "\\";
if (!Directory.Exists(filePath)) return "Error: Given path '" + filePath + "' does not exist!";
IServices services = v1Instance.ApiClient.Services;
IMetaModel metaModel = v1Instance.ApiClient.MetaModel;
//IAttachments attachments = v1Instance.ApiClient.Attachments;
Oid itemOid = services.GetOid(v1Item.ID.Token);
IAssetType assetType = metaModel.GetAssetType("EmbeddedImage");
var query = new Query(assetType);
IAttributeDefinition contentAttribute = assetType.GetAttributeDefinition("Content");
IAttributeDefinition contentTypeAttribute = assetType.GetAttributeDefinition("ContentType");
IAttributeDefinition assetAttribute = assetType.GetAttributeDefinition("Asset");
query.Selection.Add(contentAttribute);
query.Selection.Add(contentTypeAttribute);
query.Selection.Add(assetAttribute);
FilterTerm term = new FilterTerm(assetAttribute);
term.Equal(itemOid.Momentless);
query.Filter = term;
QueryResult queryResult = services.Retrieve(query);
foreach (Asset attachment in queryResult.Assets)
{
VersionOne.SDK.APIClient.Attribute attribute = attachment.GetAttribute(contentTypeAttribute);
string mimeType = "image/png";
if (attribute != null)
{
mimeType = attribute.Value.ToString();
}
string extension = MimeTypeStringToExtensionForImages(mimeType);
string attachmentID = attachment.Oid.Key.ToString();
string fileName = attachmentID + "_" + extension;
string content = attachment.GetAttribute(contentAttribute).Value.ToString();
string urlPath = Config.url;
const string commonBit = "/VersionOne";
if (urlPath.EndsWith(commonBit) && content.StartsWith(commonBit))
{
content = content.Replace(commonBit,string.Empty);
}
content = urlPath + content;
string finalFileName = filePath + "v1_img_" + fileName;
using (var client = new System.Net.WebClient())
{
client.Credentials = new System.Net.NetworkCredential(config.login,config.password);
client.DownloadFile(content,finalFileName);
countStored++;
}
}
return result;
}
因此 URL 是由配置数据和内容字符串构成的（只需进行一些处理以确保“VersionOne”在最终字符串中只出现一次），然后使用 WebClient 而不是 VersionOne API 从那里下载。