设置活动演示文稿的加密方式。   

With ActivePresentation
    If .PasswordEncryptionFileProperties = msoFalse Then
        .SetPasswordEncryptionOptions _
        PasswordEncryptionProvider:="Microsoft RSA SChannel Cryptographic Provider", _
        PasswordEncryptionAlgorithm:="RC4", _
        PasswordEncryptionKeyLength:=56, _
        PasswordEncryptionFileProperties:=True
    End If
End With