编辑

通过

DataTable.RowChanging Event

Definition

Namespace:
System.Data
Assemblies:
netstandard.dll, System.Data.Common.dll
Assembly:
System.Data.Common.dll
Assembly:
System.Data.dll
Assembly:
netstandard.dll
Source:
DataTable.cs
Source:
DataTable.cs
Source:
DataTable.cs
Source:
DataTable.cs

Occurs when a DataRow is changing.

public:
 event System::Data::DataRowChangeEventHandler ^ RowChanging;
public event System.Data.DataRowChangeEventHandler? RowChanging;
public event System.Data.DataRowChangeEventHandler RowChanging;
[System.Data.DataSysDescription("DataTableRowChangingDescr")]
public event System.Data.DataRowChangeEventHandler RowChanging;
member this.RowChanging : System.Data.DataRowChangeEventHandler 
[<System.Data.DataSysDescription("DataTableRowChangingDescr")>]
member this.RowChanging : System.Data.DataRowChangeEventHandler 
Public Custom Event RowChanging As DataRowChangeEventHandler

Event Type

DataRowChangeEventHandler
Attributes
DataSysDescriptionAttribute

Examples

private static void DataTableRowChanging()
{
    DataTable custTable = new DataTable("Customers");
    // add columns
    custTable.Columns.Add("id", typeof(int));
    custTable.Columns.Add("name", typeof(string));
    custTable.Columns.Add("address", typeof(string));

    // set PrimaryKey
    custTable.Columns[ "id" ].Unique = true;
    custTable.PrimaryKey = new DataColumn[] { custTable.Columns["id"] };

    // add a RowChanging event handler for the table.
    custTable.RowChanging += new DataRowChangeEventHandler(Row_Changing);

    // add ten rows
    for(int id=1; id<=10; id++)
    {
        custTable.Rows.Add(
            new object[] { id, string.Format("customer{0}", id),
            string.Format("address{0}", id) });
    }
    
    custTable.AcceptChanges();

    // change the name column in all the rows
    foreach(DataRow row in custTable.Rows)
    {
        row["name"] = string.Format("vip{0}", row["id"]);
    }
}

private static void Row_Changing(object sender, DataRowChangeEventArgs e)
{
    Console.WriteLine("Row_Changing Event: name={0}; action={1}",
        e.Row["name"], e.Action);
}

 Private Sub DataTableRowChanging()
     Dim custTable As New DataTable("Customers")
     ' add columns
     custTable.Columns.Add("id", Type.GetType("System.Int32"))
     custTable.Columns.Add("name", Type.GetType("System.String"))
     custTable.Columns.Add("address", Type.GetType("System.String"))

     ' set PrimaryKey
     custTable.Columns("id").Unique = True
     custTable.PrimaryKey = New DataColumn() {custTable.Columns("id")}

     ' add a RowChanging event handler for the table.
     AddHandler custTable.RowChanging, _
            New DataRowChangeEventHandler(AddressOf Row_Changing)


     ' add ten rows
     Dim id As Integer
     For id = 1 To 10
         custTable.Rows.Add( _
New Object() {id, String.Format("customer{0}", id), _
         String.Format("address{0}", id)})
     Next

     custTable.AcceptChanges()

     ' change the name column in all the rows
     Dim row As DataRow
     For Each row In custTable.Rows
         row("name") = String.Format("vip{0}", row("id"))
     Next

 End Sub

 Private Sub Row_Changing(ByVal sender As Object, _
 ByVal e As DataRowChangeEventArgs)
     Console.WriteLine("Row_Changing Event: name={0}; action={1}", _
      e.Row("name"), e.Action)
 End Sub

Remarks

For more information, see Handling DataTable Events.

Applies to

See also