DataRowView 类

定义

public ref class DataRowView : System::ComponentModel::ICustomTypeDescriptor, System::ComponentModel::IDataErrorInfo, System::ComponentModel::IEditableObject, System::ComponentModel::INotifyPropertyChanged

public ref class DataRowView : System::ComponentModel::ICustomTypeDescriptor, System::ComponentModel::IDataErrorInfo, System::ComponentModel::IEditableObject

public class DataRowView : System.ComponentModel.ICustomTypeDescriptor, System.ComponentModel.IDataErrorInfo, System.ComponentModel.IEditableObject, System.ComponentModel.INotifyPropertyChanged

public class DataRowView : System.ComponentModel.ICustomTypeDescriptor, System.ComponentModel.IDataErrorInfo, System.ComponentModel.IEditableObject

type DataRowView = class
    interface ICustomTypeDescriptor
    interface IDataErrorInfo
    interface IEditableObject
    interface INotifyPropertyChanged

type DataRowView = class
    interface ICustomTypeDescriptor
    interface IEditableObject
    interface IDataErrorInfo

type DataRowView = class
    interface ICustomTypeDescriptor
    interface IEditableObject
    interface IDataErrorInfo
    interface INotifyPropertyChanged

Public Class DataRowView
Implements ICustomTypeDescriptor, IDataErrorInfo, IEditableObject, INotifyPropertyChanged

Public Class DataRowView
Implements ICustomTypeDescriptor, IDataErrorInfo, IEditableObject

继承

Object

DataRowView

实现

ICustomTypeDescriptor IDataErrorInfo IEditableObject INotifyPropertyChanged

示例

以下示例使用 RowVersion 属性确定 中 DataRowView行的状态。 (有关使用 DataRowView.) 的另一个示例，请参阅RowFilter

private static void DemonstrateRowVersion()
{
    // Create a DataTable with one column.
    DataTable table = new DataTable("Table");
    DataColumn column = new DataColumn("Column");
    table.Columns.Add(column);

    // Add ten rows.
    DataRow row;
    for (int i = 0; i < 10; i++)
    {
        row = table.NewRow();
        row["Column"] = "item " + i;
        table.Rows.Add(row);
    }

    table.AcceptChanges();
    // Create a DataView with the table.
    DataView view = new DataView(table);

    // Change one row's value:
    table.Rows[1]["Column"] = "Hello";

    // Add one row:
    row = table.NewRow();
    row["Column"] = "World";
    table.Rows.Add(row);

    // Set the RowStateFilter to display only added
    // and modified rows.
    view.RowStateFilter = DataViewRowState.Added |
        DataViewRowState.ModifiedCurrent;

    // Print those rows. Output includes "Hello" and "World".
    PrintView(view, "ModifiedCurrent and Added");

    // Set filter to display only originals of modified rows.
    view.RowStateFilter = DataViewRowState.ModifiedOriginal;
    PrintView(view, "ModifiedOriginal");

    // Delete three rows.
    table.Rows[1].Delete();
    table.Rows[2].Delete();
    table.Rows[3].Delete();

    // Set the RowStateFilter to display only deleted rows.
    view.RowStateFilter = DataViewRowState.Deleted;
    PrintView(view, "Deleted");

    // Set filter to display only current rows.
    view.RowStateFilter = DataViewRowState.CurrentRows;
    PrintView(view, "Current");

    // Set filter to display only unchanged rows.
    view.RowStateFilter = DataViewRowState.Unchanged;
    PrintView(view, "Unchanged");

    // Set filter to display only original rows.
    // Current values of unmodified rows are also returned.
    view.RowStateFilter = DataViewRowState.OriginalRows;
    PrintView(view, "OriginalRows");
}

private static void PrintView(DataView view, string label)
{
    Console.WriteLine("\n" + label);
    for (int i = 0; i < view.Count; i++)
    {
        Console.WriteLine(view[i]["Column"]);
        Console.WriteLine("DataViewRow.RowVersion: {0}",
            view[i].RowVersion);
    }
}

Private Sub DemonstrateRowVersion()
    Dim i As Integer
    ' Create a DataTable with one column.
    Dim table As New DataTable("Table")
    Dim column As New DataColumn("Column")
    table.Columns.Add(column)

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

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

    ' Change one row's value:
    table.Rows(1)("Column") = "Hello"

    ' Add one row:
    row = table.NewRow()
    row("Column") = "World"
    table.Rows.Add(row)

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

    ' Print those rows. Output includes "Hello" and "World".
    PrintView(view, "ModifiedCurrent and Added")

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

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

    ' Set the RowStateFilter to display only deleted rows.
    view.RowStateFilter = DataViewRowState.Deleted
    PrintView(view, "Deleted")

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

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

    ' Set filter to display only original rows.
    ' Current values of unmodified rows are also returned.
    view.RowStateFilter = DataViewRowState.OriginalRows
    PrintView(view, "OriginalRows")
End Sub

Private Sub PrintView(ByVal view As DataView, ByVal label As String)
    Console.WriteLine(ControlChars.Cr + label)
    Dim i As Integer
    For i = 0 To view.Count - 1
        Console.WriteLine(view(i)("Column"))
        Console.WriteLine("DataRowView.RowVersion: {0}", _
            view(i).RowVersion)
    Next i
End Sub

注解

每当显示数据（例如在 控件中 DataGrid ）时，每行只能显示一个版本。 显示的行是 DataRowView。

DataRowView可以有四种不同的版本状态之一：Default、Original、 Current和 Proposed。

在 上DataRow调用 BeginEdit 后，任何已编辑的值都Proposed将成为 值。 CancelEdit在调用 或 EndEdit 之前，行具有 Original 和 Proposed 版本。 如果 CancelEdit 调用 ，则放弃建议的版本，并将值还原为 Original。 如果 EndEdit 调用 ，则 DataRowView 不再具有 Proposed 版本;相反，建议的值将成为当前值。 默认值仅适用于具有定义了默认值的列的行。

属性

方法

事件

显式接口实现

适用于

线程安全性

此类型对于多线程读取操作是安全的。 必须同步所有写入操作。

另请参阅

• DataRow