第三方接口对接时如何实现文件到文件流到字节的转换

情况一：指定路径的文件信息：

string path = "文件路径";

FileStream fileStream = new FileStream(path,FileMode.Open);

byte[] buffer = new Byte[fileStream.Length];

fileStream.Read(buffer, 0, buffer.Length);

fileStream.Seek(0, SeekOrigin.Begin);

fileStream.Close();

string strRet = Convert.ToBase64String(infbytes);

情况二：文件服务器的文件

string entityFullName = so.GetType().FullName;

string opath = "EntityFullName='" + entityFullName + "' and EntityID=" + so.ID;

UFIDA.U9.Base.Attachment.Attachment.EntityList attachmentList = UFIDA.U9.Base.Attachment.Attachment.Finder.FindAll(opath, null);

foreach (UFIDA.U9.Base.Attachment.Attachment attachment in attachmentList)

{

// 附件ID

long attachmentID = attachment.AttachmentID;

//根据附件ID查文件信息

//UFIDA.U9.CS.Collaboration.Library.FileInfo fileInfo = UFIDA.U9.CS.Collaboration.Library.FileInfo.Finder.FindByID(attachmentID);

//文件内容存储ID

string fileHandler = attachment