PRB: Read-Only and Write-Only Class Properties Not Accessible from a Web Service (317270)


The information in this article applies to:

  • Microsoft Visual Studio .NET (2003), Professional Edition
  • Microsoft Visual Studio .NET (2003), Enterprise Architect Edition
  • Microsoft Visual Studio .NET (2003), Enterprise Developer Edition
  • Microsoft Visual Studio .NET (2003), Academic Edition
  • Microsoft .NET Framework 1.1
  • Microsoft Visual Studio .NET (2002), Professional Edition
  • Microsoft Visual Studio .NET (2002), Enterprise Architect Edition
  • Microsoft Visual Studio .NET (2002), Enterprise Developer Edition
  • Microsoft Visual Studio .NET (2002), Academic Edition
  • Microsoft .NET Framework 1.0
This article was previously published under Q317270

SYMPTOMS

When you try to access read-only and write-only properties of a class that you obtain from a Web service, you cannot view the properties.

CAUSE

XML serialization and ASP.NET Web services do not support read-only and write-only properties. Information about these properties is not published in Web Services Description Language (WSDL) documentation.

WORKAROUND

To access the properties, use the Web methods in the WebService class. To do this, follow these steps:
  1. In the Service1.asmx.vb file, paste the following Web methods after the #Region " Web Services Designer Generated Code" block: 
    <WebMethod()> Public Function GetValue1() As Integer
        Dim c1 As New Class1()
        GetValue1 = c1.Value1
End Function

<WebMethod()> Public Function SetValue2(ByVal x As Integer) As Boolean
        Dim c2 As New Class1()
        c2.Value2 = x
        Return True
End Function
  2. In the WebForm1.aspx.vb file, instead of code that tries to directly access the properties, paste the following code in the Page_Load method:
     data="Dim i as Integer
i = myVar2.GetValue1
myVar2.SetValue2(5)"?>Dim myvar As New localhost.Service1
Dim myInt As Int32
myInt = myvar.GetValue1
myvar.SetValue2(100)

STATUS

This behavior is by design.

MORE INFORMATION

Steps to Reproduce Behavior

  1. Use Visual Basic to create a new Web service project.
  2. In Service.asmx.vb, paste the following code in the Service1 class:
    <WebMethod()> Public Function GetObject() As Class1
        GetObject = New Class1()
       End Function
  3. Paste the following class after the Service1 class:
     
Public Class Class1
    Private mVal1 As Integer
    Private mVal2 As Integer

    Public ReadOnly Property Value1() As Integer
        Get
            Value1 = mVal1
        End Get
    End Property

    Public WriteOnly Property Value2() As Integer
        Set(ByVal Value As Integer)
            mVal2 = Value
        End Set
    End Property
End Class
  4. Build the Web service.
  5. Create a new Web application.
  6. Add a Web reference to the Service1.asmx Web service. The default location for this file is the http://localhost/WebService1 folder.
  7. Declare an instance of localhost.Class1, and then attempt to access the Value1 and Value2 properties in the Page_Load method of Webform1.aspx, as follows:
         Dim myvar as localhost.Class1
     Dim myInt as Int32

     myInt = myvar.Value1
     myvar.Value2 = 100
Modification Type:MajorLast Reviewed:2/11/2004
Keywords:kbprb KB317270 kbAudDeveloper
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