在C＃中签署XML并使用XMLsignature设置签名位置

Question

我有一些代码可以用x509证书签名xml。

代码在下面。问题有时是，我不知道为什么，签名位于文件末尾（这是正确的），有时位于中间（这是错误的）。

如何强制将其放置在文件末尾？

string certID = Configuration["Signature:certID"];
string delegated_domain = Configuration["Signature:delegated_domain"];
string delegated_password = Configuration["Signature:delegated_password"];
string delegated_user = Configuration["Signature:delegated_user"];
string typeOtpAuth = Configuration["Signature:typeOtpAuth"];
string user = Configuration["Signature:user"];
string otpPwd = Configuration["Signature:otpPwd"];
string host = Configuration["Signature:host"];
XMLsignature xmlSign = new XMLsignature(certID, delegated_domain, delegated_password, delegated_user, typeOtpAuth, user, otpPwd, host);

var text = System.IO.File.ReadAllText(fullpath);

var t64 = Utility.EncodeStringToBase64(text);

var signed = await xmlSign.SignXML(t64);
var fileBytes = Convert.FromBase64String(signed);

string xml = Encoding.UTF8.GetString(fileBytes);
System.IO.File.WriteAllText(fullpath, xml);