平台叫用安全性考量
Assert, Deny, 和 SecurityAction 列舉型別的 PermitOnly 成員，被稱為「堆疊查核行程」(Stack Walk) 修飾詞。 如果在平台叫用宣告及 COM 介面定義語言 (IDL) 陳述式上，這些成員被當成宣告屬性使用，就會忽略這些成員。
平台叫用範例
本節中的平台叫用範例，說明如何利用堆疊查核行程修飾詞，以使用 RegistryPermission 屬性。
下列程式範例中，SecurityAction Assert, Deny 和 PermitOnly 修飾詞會被忽略。
[DllImport("MyClass.dll", EntryPoint = "CallRegistryPermission")]
[RegistryPermission(SecurityAction.Assert, Unrestricted = true)]
private static extern bool CallRegistryPermissionAssert();
[DllImport("MyClass.dll", EntryPoint = "CallRegistryPermission")]
[RegistryPermission(SecurityAction.Deny, Unrestricted = true)]
private static extern bool CallRegistryPermissionDeny();
[DllImport("MyClass.dll", EntryPoint = "CallRegistryPermission")]
[RegistryPermission(SecurityAction.PermitOnly, Unrestricted = true)]
private static extern bool CallRegistryPermissionDeny();
但是，下列範例就會接受 Demand 修飾詞。
[DllImport("MyClass.dll", EntryPoint = "CallRegistryPermission")]
[RegistryPermission(SecurityAction.Demand, Unrestricted = true)]
private static extern bool CallRegistryPermissionDeny();
如果 SecurityAction 修飾詞放在內含 (包裝) 平台叫用呼叫的類別中，就可以正確運作。
[RegistryPermission(SecurityAction.Demand, Unrestricted = true)]
public ref class PInvokeWrapper
{
public:
[DllImport("MyClass.dll", EntryPoint = "CallRegistryPermission")]
private static extern bool CallRegistryPermissionDeny();
};
[RegistryPermission(SecurityAction.Demand, Unrestricted = true)]
class PInvokeWrapper
{
[DllImport("MyClass.dll", EntryPoint = "CallRegistryPermission")]
private static extern bool CallRegistryPermissionDeny();
}
SecurityAction 修飾詞在巢狀案例中 (修飾詞放置在平台叫用呼叫的呼叫端上) 也可以正確運作：
{
public ref class PInvokeWrapper
public:
[DllImport("MyClass.dll", EntryPoint = "CallRegistryPermission")]
private static extern bool CallRegistryPermissionDeny();
[RegistryPermission(SecurityAction.Demand, Unrestricted = true)]
public static bool CallRegistryPermission()
{
return CallRegistryPermissionInternal();
}
};
class PInvokeScenario
{
[DllImport("MyClass.dll", EntryPoint = "CallRegistryPermission")]
private static extern bool CallRegistryPermissionInternal();
[RegistryPermission(SecurityAction.Assert, Unrestricted = true)]
public static bool CallRegistryPermission()
{
return CallRegistryPermissionInternal();
}
}
COM Interop 範例
本節中的 COM Interop 範例，說明如何利用堆疊查核行程修飾詞，以使用 RegistryPermission 屬性。
下列 COM Interop 介面宣告會忽略 Assert、Deny 和 PermitOnly 修飾詞，類似上一節中的平台叫用範例。
[ComImport, Guid("12345678-43E6-43c9-9A13-47F40B338DE0")]
interface IAssertStubsItf
{
[RegistryPermission(SecurityAction.Assert, Unrestricted = true)]
bool CallRegistryPermission();
[FileIOPermission(SecurityAction.Assert, Unrestricted = true)]
bool CallFileIoPermission();
}
[ComImport, Guid("12345678-43E6-43c9-9A13-47F40B338DE0")]
interface IDenyStubsItf
{
[RegistryPermission(SecurityAction.Deny, Unrestricted = true)]
bool CallRegistryPermission();
[FileIOPermission(SecurityAction.Deny, Unrestricted = true)]
bool CallFileIoPermission();
}
[ComImport, Guid("12345678-43E6-43c9-9A13-47F40B338DE0")]
interface IAssertStubsItf
{
[RegistryPermission(SecurityAction.PermitOnly, Unrestricted = true)]
bool CallRegistryPermission();
[FileIOPermission(SecurityAction.PermitOnly, Unrestricted = true)]
bool CallFileIoPermission();
}
此外，COM Interop 介面宣告案例中不接受 Demand 修飾詞，如以下範例所示。
[ComImport, Guid("12345678-43E6-43c9-9A13-47F40B338DE0")]
interface IDemandStubsItf
{
[RegistryPermission(SecurityAction.Demand, Unrestricted = true)]
bool CallRegistryPermission();
[FileIOPermission(SecurityAction.Demand, Unrestricted = true)]
bool CallFileIoPermission();
}