StateChangeEventArgs Class

 

Provides data for the state change event of a .NET Framework data provider.

Namespace:   System.Data
Assembly:  System.Data (in System.Data.dll)

System.Object
  System.EventArgs
    System.Data.StateChangeEventArgs

Public NotInheritable Class StateChangeEventArgs
	Inherits EventArgs

NameDescription
System_CAPS_pubmethodStateChangeEventArgs(ConnectionState, ConnectionState)

Initializes a new instance of the StateChangeEventArgs class, when given the original state and the current state of the object.

NameDescription
System_CAPS_pubpropertyCurrentState

Gets the new state of the connection. The connection object will be in the new state already when the event is fired.

System_CAPS_pubpropertyOriginalState

Gets the original state of the connection.

NameDescription
System_CAPS_pubmethodEquals(Object)

Determines whether the specified object is equal to the current object.(Inherited from Object.)

System_CAPS_pubmethodGetHashCode()

Serves as the default hash function. (Inherited from Object.)

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethodToString()

Returns a string that represents the current object.(Inherited from Object.)

The data is used by the StateChange property of the OleDbConnection and the StateChange property of the SqlConnection.

The following example shows how to use the StateChange event within the SqlConnection class.

' Handler for the OnStateChange event.
Private Sub OnStateChange(ByVal sender As Object, _
    ByVal e As StateChangeEventArgs)
    PrintEventArgs(e)
End Sub

Sub Main()
    FillDataSet()
End Sub

Private Sub FillDataSet()
    Dim connectionString As String = GetConnectionString()
    Dim queryString As String = _
        "SELECT ProductID, UnitPrice from dbo.Products;"

    ' Create a DataAdapter.
    Using dataAdapter As New SqlDataAdapter( _
        queryString, connectionString)

        ' Add the handlers.
        AddHandler dataAdapter.SelectCommand.Connection.StateChange, _
            AddressOf OnStateChange

        ' Create a DataSet.
        Dim dataSet As New DataSet()

        ' Fill the DataSet, which fires several StateChange events.
        dataAdapter.Fill(dataSet, 0, 5, "Table")
    End Using
End Sub

Private Sub PrintEventArgs(ByVal args As StateChangeEventArgs)
    Console.WriteLine("StateChangeEventArgs")
    Console.WriteLine("  OriginalState= {0} CurrentState= {1}", _
        args.OriginalState, args.CurrentState)
End Sub

Private Function GetConnectionString() As String
    ' To avoid storing the connection string in your code,  
    ' you can retrieve it from a configuration file.
    Return "Data Source=(local);Initial Catalog=Northwind;" _
       & "Integrated Security=true;"
End Function

Universal Windows Platform
Available since 10
.NET Framework
Available since 1.1

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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