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DataTable.ColumnChanging Event

Occurs when a value is being changed for the specified DataColumn in a DataRow.

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

public event DataColumnChangeEventHandler ColumnChanging

For more information, see Handling DataTable Events.

    private static void DataTableColumnChanging()
    {
        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 ColumnChanging event handler for the table.
        custTable.ColumnChanging += new 
            DataColumnChangeEventHandler(Column_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 Column_Changing(object sender, 
        DataColumnChangeEventArgs e )
    {
        Console.WriteLine(
            "Column_Changing Event: name={0}; Column={1}; proposed name={2}", 
            e.Row["name"], e.Column.ColumnName, e.ProposedValue );
    }

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

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.

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