提问人：Tamtomo Abdi Negoro 提问时间：11/14/2023 最后编辑：Tamtomo Abdi Negoro 更新时间：11/14/2023 访问量：31
检索附件名称并下载附件
Retrieving attachment names and downloading the attachments
问：
希望这里有人能启发我如何使用 Microsoft Graph 从电子邮件中下载附件。我正在尝试从具有特定主题的 Office 365 邮件中自动下载和处理附件。到目前为止，我已经设法迭代了这些消息并将它们放在一个名为messageList的列表中，但尚未成功检索每封邮件中的附件名称并下载它们。这是我的代码：
var messages = await graphClient
.Users[userEmail]
.MailFolders[folderId]
.Messages
.GetAsync((requestConfiguration) =>
{
//requestConfiguration.QueryParameters.Count = true;
//requestConfiguration.Headers.Add("ConsistencyLevel", "eventual");
requestConfiguration.QueryParameters.Filter =
"receivedDateTime ge 1900-01-01T00:00:00Z and (from/emailAddress/address) eq '[email protected]'";
requestConfiguration.QueryParameters.Orderby = new string[] { "receivedDateTime desc"};
});
var messageList = new List<Message>();
var pageIterator = PageIterator<Message, MessageCollectionResponse>.
CreatePageIterator(graphClient, messages, (message) =>
{
//Console.WriteLine(message.Subject);
messageList.Add(message);
return true;
});
await pageIterator.IterateAsync();
while (pageIterator.State != PagingState.Complete)
{
await pageIterator.IterateAsync();
}
foreach (var m in messageList)
{
if (m.HasAttachments == true)
{
var attachments=m.Attachments;
if (attachments != null)
{
foreach (var attachment in attachments)
{
Console.WriteLine("Attachment Name : " + attachment.Name);
}
}
Console.WriteLine(m.Subject + " Has attachment(s)");
}
}
如果我在 Autos 中查看 m 对象，它的 Attachment 属性为 null。
请帮忙，尤其是在下载文件时。提前感谢您的帮助。
答：
1赞
user2250152
11/14/2023
#1
默认情况下不包括附件，您需要使用 expand 告诉服务器响应中应包含附件。然后，您需要强制转换每个附件才能读取数据FileAttachment
var messages = await graphClient
.Users[""]
.MailFolders[""]
.Messages
.GetAsync((requestConfiguration) =>
{
requestConfiguration.QueryParameters.Filter =
"receivedDateTime ge 1900-01-01T00:00:00Z and (from/emailAddress/address) eq '[email protected]'";
requestConfiguration.QueryParameters.Orderby = new string[] { "receivedDateTime desc" };
// return also attachments
requestConfiguration.QueryParameters.Expand = new string[] { "attachments" };
});
var messageList = new List<Message>();
var pageIterator = PageIterator<Message, MessageCollectionResponse>.
CreatePageIterator(graphClient, messages, (message) =>
{
//Console.WriteLine(message.Subject);
messageList.Add(message);
return true;
});
await pageIterator.IterateAsync();
while (pageIterator.State != PagingState.Complete)
{
await pageIterator.IterateAsync();
}
foreach (var m in messageList)
{
if (m.HasAttachments == true)
{
foreach (var attachment in m.Attachments)
{
Console.WriteLine("Attachment Name : " + attachment.Name);
if (attachment is FileAttachment fileAttachment)
{
// content is base64 encoded bytes
var base64String = Encoding.ASCII.GetString(fileAttachment.ContentBytes);
var bytes = Convert.FromBase64String(base64String);
File.WriteAllBytes("path", bytes);
}
}
}
Console.WriteLine(m.Subject + " Has attachment(s)");
}
从性能的角度来看，过滤带有附件的邮件会更好
var messages = await graphClient
.Users[""]
.MailFolders[""]
.Messages
.GetAsync((requestConfiguration) =>
{
requestConfiguration.QueryParameters.Filter =
"receivedDateTime ge 1900-01-01T00:00:00Z and (from/emailAddress/address) eq '[email protected]' and hasAttachments eq true";
requestConfiguration.QueryParameters.Orderby = new string[] { "receivedDateTime desc" };
});
对于每封邮件，请单独调用以返回附件
var attachments = await graphClient
.Users[""]
.MailFolders[""]
.Messages["{message_id}"].Attachments.GetAsync()
评论
0赞
Tamtomo Abdi Negoro
11/14/2023
非常感谢马丁，你摇滚。伙计，Microsoft真的不一样了，哈哈。下次再次使用 Microsoft API 时，我会检查查询参数
评论
foreach (var m in messageList)