IsValid

IDigitalSignature.IsValid property

如果此数字签名有效且文档未被篡改，则此值为真。 只读Boolean。

public bool IsValid { get; }

例子

[C#]
using (Presentation pres = new Presentation("SomePresentationSigned.pptx"))
{
    foreach (DigitalSignature signature in pres.DigitalSignatures)
        Console.WriteLine("Signature check: " + (signature.IsValid ? "VALID" : "INVALID"));
}

也可以看看

Comments SignTime