DnsPermissionAttribute(SecurityAction) 构造函数
定义
使用指定的 SecurityAction 值初始化 DnsPermissionAttribute 类的新实例。Initializes a new instance of the DnsPermissionAttribute class with the specified SecurityAction value.
public:
DnsPermissionAttribute(System::Security::Permissions::SecurityAction action);
public DnsPermissionAttribute (System.Security.Permissions.SecurityAction action);
new System.Net.DnsPermissionAttribute : System.Security.Permissions.SecurityAction -> System.Net.DnsPermissionAttribute
Public Sub New (action As SecurityAction)
参数
- action
- SecurityAction
SecurityAction 值之一。One of the SecurityAction values.
例外
action 参数不是有效的 SecurityAction。The action parameter is not a valid SecurityAction.
示例
下面的示例使用将 DnsPermissionAttribute 声明性安全应用于自定义类。The following example uses DnsPermissionAttribute to apply declarative security to a custom class.
//Uses the DnsPermissionAttribute to restrict access only to those who have permission.
[DnsPermission(SecurityAction::Demand,Unrestricted=true)]
public ref class MyClass
{
public:
static IPAddress^ GetIPAddress()
{
IPAddress^ ipAddress = Dns::Resolve( "localhost" )->AddressList[ 0 ];
return ipAddress;
}
};
int main()
{
try
{
//Grants Access.
Console::WriteLine( " Access granted\n The local host IP Address is :{0}", MyClass::GetIPAddress() );
}
// Denies Access.
catch ( SecurityException^ securityException )
{
Console::WriteLine( "Access denied" );
Console::WriteLine( securityException->ToString() );
}
}
//Uses the DnsPermissionAttribute to restrict access only to those who have permission.
[DnsPermission(SecurityAction.Demand, Unrestricted = true)]
public class MyClass
{
public static IPAddress GetIPAddress()
{
IPAddress ipAddress = Dns.Resolve("localhost").AddressList[0];
return ipAddress;
}
public static void Main()
{
try
{
//Grants Access.
Console.WriteLine(" Access granted\n The local host IP Address is :" +
MyClass.GetIPAddress().ToString());
}
// Denies Access.
catch (SecurityException securityException)
{
Console.WriteLine("Access denied");
Console.WriteLine(securityException.ToString());
}
' Uses the DnsPermissionAttribute to restrict access only to those who have permission.
<DnsPermission(SecurityAction.Demand, Unrestricted := true)> _
Public Class MyClass1
Public Shared Function GetIPAddress() As IPAddress
Dim ipAddress As IPAddress = Dns.Resolve("localhost").AddressList(0)
Return ipAddress
End Function 'GetIPAddress
Public Shared Sub Main()
Try
' Grants Access.
Console.WriteLine(("Access granted" + ControlChars.NewLine + " The local host IP Address is :" + MyClass1.GetIPAddress().ToString()))
' Denies Access.
Catch securityException As SecurityException
Console.WriteLine("Access denied")
Console.WriteLine(securityException.ToString())
End Try
End Sub
End Class
注解
SecurityAction传递给此构造函数的值指定允许的 DnsPermissionAttribute 目标。The SecurityAction value that is passed to this constructor specifies the allowable DnsPermissionAttribute targets.