ConstructionEnabledAttribute 類別

定義

命名空間:

System.EnterpriseServices

組件:

System.EnterpriseServices.dll

啟用 COM+ 物件建構支援。 此類別無法獲得繼承。

public ref class ConstructionEnabledAttribute sealed : Attribute

[System.AttributeUsage(System.AttributeTargets.Class, Inherited=true)]
[System.Runtime.InteropServices.ComVisible(false)]
public sealed class ConstructionEnabledAttribute : Attribute

[<System.AttributeUsage(System.AttributeTargets.Class, Inherited=true)>]
[<System.Runtime.InteropServices.ComVisible(false)>]
type ConstructionEnabledAttribute = class
    inherit Attribute

Public NotInheritable Class ConstructionEnabledAttribute
Inherits Attribute

繼承

Object

Attribute

ConstructionEnabledAttribute

屬性

AttributeUsageAttribute ComVisibleAttribute

範例

下列程式代碼範例示範如何使用這個屬性，將物件建構函式字串與 ServicedComponent 類別產生關聯。

// Accept a constructor string.

[ConstructionEnabled]
public ref class EmployeeInformation: public ServicedComponent
{
private:

   // The employee's user name and salary.
   String^ accountName;
   double salary;

public:

   // Get the employee's name. All users can call this method.
   String^ GetName()
   {
      return (accountName);
   }

   // Set the employee's salary. Only managers can do this.
   void SetSalary( double ammount )
   {
      if ( SecurityCallContext::CurrentCall->IsCallerInRole( "Manager" ) )
      {
         salary = ammount;
      }
      else
      {
         throw gcnew UnauthorizedAccessException;
      }
   }

   // Get the employee's salary. Only the employee and managers can do this.
   double GetSalary()
   {
      if ( SecurityCallContext::CurrentCall->DirectCaller->AccountName == accountName || SecurityCallContext::CurrentCall->IsCallerInRole( "Manager" ) )
      {
         return (salary);
      }
      else
      {
         throw gcnew UnauthorizedAccessException;
      }
   }

protected:
   // Use the constructor string.
   // This method is called when the object is instantiated.
   virtual void Construct( String^ constructorString ) override
   {
      accountName = constructorString;
   }
};

// Accept a constructor string.
[ConstructionEnabled]

public class EmployeeInformation : ServicedComponent
{

    // The employee's user name and salary.
    private string accountName;
    private double salary = 0;

    // Get the employee's name. All users can call this method.
    public string GetName ()
    {
      return(accountName);
    }

    // Set the employee's salary. Only managers can do this.
    public void SetSalary (double ammount)
    {
        if (SecurityCallContext.CurrentCall.IsCallerInRole("Manager"))
        {
            salary = ammount;
        }
        else
        {
            throw new UnauthorizedAccessException();
        }
    }

    // Get the employee's salary. Only the employee and managers can do this.
    public double GetSalary ()
    {
        if ( SecurityCallContext.CurrentCall.DirectCaller.AccountName == accountName ||
             SecurityCallContext.CurrentCall.IsCallerInRole("Manager") )
        {
            return(salary);
        }
        else
        {
          throw new UnauthorizedAccessException();
        }
    }

    // Use the constructor string.
    // This method is called when the object is instantiated.
    protected override void Construct (string constructorString)
    {
        accountName = constructorString;
    }
}

' Accept a constructor string.
<ConstructionEnabled()>  _
Public Class EmployeeInformation
    
    Inherits ServicedComponent
    
    ' The employee's user name and salary.
    Private accountName As String
    Private salary As Double = 0
    
    ' Get the employee's name. All users can call this method.
    Public Function GetName() As String 
        Return accountName
    
    End Function 'GetName
    
    ' Set the employee's salary. Only managers can do this.
    Public Sub SetSalary(ByVal ammount As Double) 
        If SecurityCallContext.CurrentCall.IsCallerInRole("Manager") Then
            salary = ammount
        Else
            Throw New UnauthorizedAccessException()
        End If
    
    End Sub
    
    ' Get the employee's salary. Only the employee and managers can do this.
    Public Function GetSalary() As Double 
        If SecurityCallContext.CurrentCall.DirectCaller.AccountName = accountName OrElse SecurityCallContext.CurrentCall.IsCallerInRole("Manager") Then
            Return salary
        Else
            Throw New UnauthorizedAccessException()
        End If
    
    End Function 'GetSalary
    
    ' Use the constructor string.
    ' This method is called when the object is instantiated.
    Protected Overrides Sub Construct(ByVal constructorString As String) 
        accountName = constructorString
    
    End Sub

End Class

備註

如需 實例 ConstructionEnabledAttribute的初始屬性值清單，請參閱 建 ConstructionEnabledAttribute 構函式。

如需使用屬性的詳細資訊，請參閱 屬性。

建構函式

ConstructionEnabledAttribute()	初始化 ConstructionEnabledAttribute 類別的新執行個體，並初始化 Enabled 和 Default 的預設設定。
ConstructionEnabledAttribute(Boolean)	將 Enabled 設定為指定值，初始化 ConstructionEnabledAttribute 類別的新執行個體。

屬性

Default	取得或設定建構函式字串的預設值。
Enabled	取得或設定值，指出是否啟用 COM+ 物件建構支援。
TypeId	在衍生類別中實作時，取得這個 Attribute 的唯一識別碼。 (繼承來源 Attribute)

方法

Equals(Object)	傳回值，這個值指出此執行個體是否與指定的物件相等。 (繼承來源 Attribute)
GetHashCode()	傳回這個執行個體的雜湊碼。 (繼承來源 Attribute)
GetType()	取得目前執行個體的 Type。 (繼承來源 Object)
IsDefaultAttribute()	在衍生類別中覆寫時，表示這個執行個體的值是衍生類別的預設值。 (繼承來源 Attribute)
Match(Object)	在衍生類別中覆寫時，會傳回值，表示這個執行個體是否等於指定物件。 (繼承來源 Attribute)
MemberwiseClone()	建立目前 Object 的淺層複製。 (繼承來源 Object)
ToString()	傳回代表目前物件的字串。 (繼承來源 Object)

明確介面實作

_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)	將一組名稱對應至一組對應的分派識別項 (Dispatch Identifier)。 (繼承來源 Attribute)
_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)	擷取物件的類型資訊，可以用來取得介面的類型資訊。 (繼承來源 Attribute)
_Attribute.GetTypeInfoCount(UInt32)	擷取物件提供的類型資訊介面數目 (0 或 1)。 (繼承來源 Attribute)
_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)	提供物件所公開的屬性和方法的存取權。 (繼承來源 Attribute)