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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

    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++)
                new object[] { id, string.Format(
                "customer{0}", id), string.Format("address{0}", id) });

        // 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 )
            "Column_Changing Event: name={0}; Column={1}; proposed name={2}", 
            e.Row["name"], e.Column.ColumnName, e.ProposedValue );

.NET Framework

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

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.