DataViewRowState Enumeration

 

Describes the version of data in a DataRow.

This enumeration has a FlagsAttribute attribute that allows a bitwise combination of its member values.

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

<FlagsAttribute>
Public Enumeration DataViewRowState

Member nameDescription
Added

A new row.

CurrentRows

Current rows including unchanged, new, and modified rows. By default, DataViewRowState is set to CurrentRows.

Deleted

A deleted row.

ModifiedCurrent

A current version of original data that has been modified (see ModifiedOriginal).

ModifiedOriginal

The original version of the data that was modified. (Although the data has since been modified, it is available as ModifiedCurrent).

None

None.

OriginalRows

Original rows including unchanged and deleted rows.

Unchanged

An unchanged row.

The DataViewRowState values are used either to retrieve a particular version of data from a DataRow, or to determine what versions exist.

Set the RowStateFilter property of the DataView to specify which version or versions of data you want to view.

You can use the Boolean operator Or with the values to get more than one version.

The DataTable uses DataViewRowState in the Select method.

In the following example DataTable is created with a single column. The data is changed, and the RowStateFilter of the DataView is set to display different row sets, depending on the DataViewRowState.

Private Sub DemonstrateRowState()
    Dim i As Integer

    ' Create a DataTable with one column.
    Dim dataTable As New DataTable("dataTable")
    Dim dataColumn As New DataColumn("dataColumn")
    dataTable.Columns.Add(dataColumn)

    ' Add ten rows.
    Dim dataRow As DataRow
    For i = 0 To 9
        dataRow = dataTable.NewRow()
        dataRow("dataColumn") = "item " + i.ToString()
        dataTable.Rows.Add(dataRow)
    Next i
    dataTable.AcceptChanges()

    ' Create a DataView with the table.
    Dim dataView As New DataView(dataTable)

    ' Change one row's value:
    dataTable.Rows(1)("dataColumn") = "Hello"

    ' Add one row:
    dataRow = dataTable.NewRow()
    dataRow("dataColumn") = "World"
    dataTable.Rows.Add(dataRow)

    ' Set the RowStateFilter to display only Added and modified rows.
    dataView.RowStateFilter = _
    DataViewRowState.Added Or DataViewRowState.ModifiedCurrent

    ' Print those rows. Output = "Hello" "World";
    PrintView(dataView, "ModifiedCurrent and Added")

    ' Set filter to display on originals of modified rows.
    dataView.RowStateFilter = DataViewRowState.ModifiedOriginal
    PrintView(dataView, "ModifiedOriginal")

    ' Delete three rows.
    dataTable.Rows(1).Delete()
    dataTable.Rows(2).Delete()
    dataTable.Rows(3).Delete()

    ' Set the RowStateFilter to display only Added and modified rows.
    dataView.RowStateFilter = DataViewRowState.Deleted
    PrintView(dataView, "Deleted")

    'Set filter to display only current.
    dataView.RowStateFilter = DataViewRowState.CurrentRows
    PrintView(dataView, "Current")

    ' Set filter to display only unchanged rows.
    dataView.RowStateFilter = DataViewRowState.Unchanged
    PrintView(dataView, "Unchanged")

    ' Set filter to display only original rows.
    dataView.RowStateFilter = DataViewRowState.OriginalRows
    PrintView(dataView, "OriginalRows")
End Sub

Private Sub PrintView(ByVal dataView As DataView, ByVal label As String)
    Console.WriteLine(ControlChars.Cr + label)
    Dim i As Integer
    For i = 0 To dataView.Count - 1
        Console.WriteLine(dataView(i)("dataColumn"))
    Next i
End Sub

.NET Framework
Available since 1.1
Return to top
Show: