ปลดล็อก PPT โดยใช้ C#

LoadOptions loadOptions = new LoadOptions {Password = "123123"};
using (Presentation presentation = new Presentation("pres.ppt", loadOptions))
{
    presentation.ProtectionManager.RemoveEncryption();
    presentation.Save("encryption-removed.ppt", SaveFormat.Ppt);
}

using (Presentation presentation = new Presentation("pres.ppt"))
{
    presentation.ProtectionManager.RemoveWriteProtection();
    presentation.Save("write-protection-removed.ppt", SaveFormat.Ppt);
}