ObsoleteAttribute.IsError Eigenschaft

Definition

Namespace:

System

Assembly:

System.Runtime.dll

Quelle:

ObsoleteAttribute.cs

Ruft einen Wert ab, der angibt, ob der Compiler die Verwendung des veralteten Programmelements als Fehler behandelt.

public:
 property bool IsError { bool get(); };

public bool IsError { get; }

member this.IsError : bool

Public ReadOnly Property IsError As Boolean

Eigenschaftswert

Boolean

true, wenn die Verwendung des veralteten Elements als Fehler zu behandeln ist, andernfalls false. Der Standardwert ist false.

Beispiele

Im folgenden Beispiel wird eine Klasse definiert, die zwei als veraltet markierte Member enthält. Die erste, eine Eigenschaft namens OldProperty, erzeugt eine Compilerwarnung, wenn sie aufgerufen wird. Die zweite Methode mit dem Namen CallOldMethoderzeugt einen Compilerfehler. Das Beispiel verwendet Reflektion, um Informationen zu den Attributen abzurufen, die ObsoleteAttribute auf Member des Typs angewendet werden, und zeigt die Werte ihrer Message Eigenschaften und IsError an.

using System;
using System.Reflection;

public class Example
{
   // Mark OldProperty As Obsolete.
   [ObsoleteAttribute("This property is obsolete. Use NewProperty instead.", false)]
   public string OldProperty
   { get { return "The old property value."; } }

   public string NewProperty
   { get { return "The new property value."; } }

   // Mark OldMethod As Obsolete.
   [ObsoleteAttribute("This method is obsolete. Call NewMethod instead.", true)]
   public string OldMethod()
   {
      return "You have called OldMethod.";
   }

   public string NewMethod()
   {
      return "You have called NewMethod.";
   }

   public static void Main()
   {
      // Get all public members of this type.
      MemberInfo[] members = typeof(Example).GetMembers();
      // Count total obsolete members.
      int n = 0;

      // Try to get the ObsoleteAttribute for each public member.
      Console.WriteLine("Obsolete members in the Example class:\n");
      foreach (var member in members) {
         ObsoleteAttribute[] attribs = (ObsoleteAttribute[])
                                        member.GetCustomAttributes(typeof(ObsoleteAttribute),
                                                                   false);
         if (attribs.Length > 0) {
            ObsoleteAttribute attrib = attribs[0];
            Console.WriteLine("Member Name: {0}.{1}", member.DeclaringType.FullName, member.Name);
            Console.WriteLine("   Message: {0}", attrib.Message);
            Console.WriteLine("   Warning/Error: {0}", attrib.IsError ? "Error" : "Warning");
            n++;
         }
      }

      if (n == 0)
         Console.WriteLine("The Example type has no obsolete attributes.");
   }
}
// The example displays the following output:
//       Obsolete members in the Example class:
//
//       Member Name: Example.OldMethod
//          Message: This method is obsolete. Call NewMethod instead.
//          Warning/Error: Error
//       Member Name: Example.OldProperty
//          Message: This property is obsolete. Use NewProperty instead.
//          Warning/Error: Warning

open System

type Example() =
    // Mark OldProperty As Obsolete.
    [<ObsoleteAttribute("This property is obsolete. Use NewProperty instead.", false)>]
    member _.OldProperty =
        "The old property value."

    member _.NewProperty =
        "The new property value."

    // Mark OldMethod As Obsolete.
    [<ObsoleteAttribute("This method is obsolete. Call NewMethod instead.", true)>]
    member _.OldMethod() =
        "You have called OldMethod."

    member _.NewMethod() =
        "You have called NewMethod."

// Get all public members of this type.
let members = typeof<Example>.GetMembers()
// Count total obsolete members.
let mutable n = 0

// Try to get the ObsoleteAttribute for each public member.
printfn "Obsolete members in the Example class:\n"
for m in members do
    let attribs = m.GetCustomAttributes(typeof<ObsoleteAttribute>, false) |> box :?> ObsoleteAttribute[]
    if attribs.Length > 0 then
        let attrib = attribs[0]
        printfn $"Member Name: {m.DeclaringType.FullName}.{m.Name}"
        printfn $"   Message: {attrib.Message}"
        printfn $"""   Warning/Error: {if attrib.IsError then "Error" else "Warning"}"""
        n <- n + 1

if n = 0 then
    printfn "The Example type has no obsolete attributes."
// The example displays the following output:
//       Obsolete members in the Example class:
//
//       Member Name: Example+Example.OldMethod
//          Message: This method is obsolete. Call NewMethod instead.
//          Warning/Error: Error
//       Member Name: Example+Example.OldProperty
//          Message: This property is obsolete. Use NewProperty instead.
//          Warning/Error: Warning

Imports System.Reflection

Public Module Example
   ' Mark OldProperty As Obsolete.
   <ObsoleteAttribute("This property is obsolete. Use NewProperty instead.", False)> 
   Public ReadOnly Property OldProperty As String
      Get
         Return "The old property value."
      End Get
   End Property
   
   Public ReadOnly Property NewProperty As String
      Get
         Return "The new property value."
      End Get
   End Property
   
   ' Mark OldMethod As Obsolete.
   <ObsoleteAttribute("This method is obsolete. Call NewMethod instead.", True)> 
   Public Function OldMethod() As String
      Return "You have called OldMethod."
   End Function
      
   Public Function NewMethod() As String   
      Return "You have called NewMethod."
   End Function   
   
   Public Sub Main()
      ' Get all public members of this type.
      Dim members() As MemberInfo = GetType(Example).GetMembers()
      ' Count total obsolete members.
      Dim n As Integer = 0
      
      ' Try to get the ObsoleteAttribute for each public member.
      Console.WriteLine("Obsolete members in the Example class:")
      Console.WriteLine()
      For Each member In members
         Dim attribs() As ObsoleteAttribute = CType(member.GetCustomAttributes(GetType(ObsoleteAttribute), 
                                                                             False), ObsoleteAttribute())
         If attribs.Length > 0 Then
            Dim attrib As ObsoleteAttribute = attribs(0)
            Console.WriteLine("Member Name: {0}.{1}", member.DeclaringType.FullName, member.Name)
            Console.WriteLine("   Message: {0}", attrib.Message)             
            Console.WriteLine("   Warning/Error: {0}", if(attrib.IsError, "Error", "Warning"))      
            n += 1
         End If
      Next
      
      If n = 0 Then
         Console.WriteLine("The Example type has no obsolete attributes.")
      End If 
   End Sub  
End Module
' The example displays the following output:
'       Obsolete members in the Example class:
'       
'       Member Name: Example.OldMethod
'          Message: This method is obsolete. Call NewMethod instead.
'          Warning/Error: Error
'       Member Name: Example.OldProperty
'          Message: This property is obsolete. Use NewProperty instead.
'          Warning/Error: Warning