Export (0) Print
Expand All

DataContractSerializer.IsStartObject Method (XmlDictionaryReader)

Determines whether the XmlDictionaryReader is positioned on an object that can be deserialized.

Namespace:  System.Runtime.Serialization
Assembly:  System.Runtime.Serialization (in System.Runtime.Serialization.dll)

'Declaration
Public Overrides Function IsStartObject ( _
	reader As XmlDictionaryReader _
) As Boolean

Parameters

reader
Type: System.Xml.XmlDictionaryReader

An XmlDictionaryReader used to read the XML stream.

Return Value

Type: System.Boolean
true if the reader is at the start element of the stream to read; otherwise, false.

The IsStartObject determines whether it can read an object by checking that it is positioned on an XML element. It also examines the name and namespace of the XML element that the reader is positioned at and compares the values to the expected name and namespace. The expected name and namespace can be set with the following: the data contract name and namespace of the type passed into the constructor, or the rootName and rootNamespace values passed into the constructor (if present).

The following example uses the IsStartObject property to determine whether the start of the data has been found.

Public Shared Sub ReadObjectData(ByVal path As String) 
    ' Create the reader. 
    Dim fs As New FileStream(path, FileMode.Open)
    Dim reader As XmlDictionaryReader = _
        XmlDictionaryReader.CreateTextReader(fs, New XmlDictionaryReaderQuotas())

    ' Create the DataContractSerializer specifying the type,  
    ' root and namespace to use. The root value corresponds 
    ' to the DataContract.Name value, and the namespace value 
    ' corresponds to the DataContract.Namespace value. 
    Dim ser As New DataContractSerializer(GetType(Person), _
        "Customer", "http://www.contoso.com")

    ' Test if the serializer is on the start of the  
    ' object data. If so, read the data and write it  
    ' to the console. 
    While reader.Read()
        If ser.IsStartObject(reader) Then
            Console.WriteLine("Found the element")
            Dim p As Person = CType(ser.ReadObject(reader), Person)
            Console.WriteLine("{0} {1}    id:{2}", p.FirstName, p.LastName, p.ID)
        End If

        Console.WriteLine(reader.Name)
    End While

    fs.Flush()
    fs.Close()

End Sub     

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Show:
© 2014 Microsoft