注意：拉取文件块时，两个成功块之间的时间应该在设定时间（60秒）内完成。
Task<FileSectionResult> PullFileSectionAsync(
FileSection fileSection,
int millisecondsTimeout = 5000,
CancellationToken token = default
)Function PullFileSectionAsync (
fileSection As FileSection,
Optional millisecondsTimeout As Integer = 5000,
Optional token As CancellationToken = Nothing
) As Task(Of FileSectionResult)abstract PullFileSectionAsync :
fileSection : FileSection *
?millisecondsTimeout : int *
?token : CancellationToken
(* Defaults:
let _millisecondsTimeout = defaultArg millisecondsTimeout 5000
let _token = defaultArg token new CancellationToken()
*)
-> Task<FileSectionResult> [缺少 "M:TouchSocket.Dmtp.FileTransfer.IDmtpFileTransferActor.PullFileSectionAsync(TouchSocket.Dmtp.FileTransfer.FileSection,System.Int32,System.Threading.CancellationToken)" 的 <returns> 文档]