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CompositeDataBoundControl.CreateChildControls Method (IEnumerable, Boolean)

When overridden in an abstract class, creates the control hierarchy that is used to render the composite data-bound control based on the values from the specified data source.

Namespace: System.Web.UI.WebControls
Assembly: System.Web (in system.web.dll)

protected abstract int CreateChildControls (
	IEnumerable dataSource,
	bool dataBinding
)
protected abstract int CreateChildControls (
	IEnumerable dataSource, 
	boolean dataBinding
)
protected abstract function CreateChildControls (
	dataSource : IEnumerable, 
	dataBinding : boolean
) : int
Not applicable.

Parameters

dataSource

An IEnumerable that contains the values to bind to the control.

dataBinding

true to indicate that the CreateChildControls(IEnumerable,Boolean) is called during data binding; otherwise, false.

Return Value

The number of items created by the CreateChildControls(IEnumerable,Boolean).

The CreateChildControls method is a helper method that is used by classes that derive from the CompositeDataBoundControl class to create the control hierarchy for a composite data-bound control. When extending the CompositeDataBoundControl class, you must override the CreateChildControls method to create your own control hierarchy. For more information on creating a composite control, see Developing Custom ASP.NET Server Controls.

The following code example demonstrates how to override the CreateChildControls(IEnumerable,Boolean) method in a custom control to create the control hierarchy.

using System;
using System.Collections;
using System.Data.Common;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace Samples.AspNet.CS
{
    public class SimpleSpreadsheetControl : CompositeDataBoundControl
    {
        protected Table table = new Table();

        public virtual TableRowCollection Rows
        {
            get
            {
                return table.Rows;
            }
        }

        protected override int CreateChildControls(IEnumerable dataSource, bool dataBinding)
        {

            int count = 0;
            // If dataSource is not null, iterate through it and
            // extract each element from it as a row, then
            // create a SimpleSpreadsheetRow and add it to the
            // rows collection.
            if (dataSource != null)
            {

                SimpleSpreadsheetRow row;
                IEnumerator e = dataSource.GetEnumerator();

                while (e.MoveNext())
                {
                    object datarow = e.Current;
                    row = new SimpleSpreadsheetRow(count, datarow);
                    this.Rows.Add(row);
                    ++count;
                }

                Controls.Add(table);
            }
            return count;
        }
    }

    //
    //
    public class SimpleSpreadsheetRow : TableRow, IDataItemContainer
    {
        private object data;
        private int _itemIndex;

        public SimpleSpreadsheetRow(int itemIndex, object o)
        {
            data = o;
            _itemIndex = itemIndex;
        }

        public virtual object Data
        {
            get
            {
                return data;
            }
        }
        object IDataItemContainer.DataItem
        {
            get
            {
                return Data;
            }
        }
        int IDataItemContainer.DataItemIndex
        {
            get
            {
                return _itemIndex;
            }
        }
        int IDataItemContainer.DisplayIndex
        {
            get
            {
                return _itemIndex;
            }
        }
        protected override void RenderContents(HtmlTextWriter writer)
        {

            if (Data != null)
            {
                if (Data is System.Data.Common.DbDataRecord)
                {
                    DbDataRecord temp = (DbDataRecord)Data;
                    for (int i = 0; i < temp.FieldCount; ++i)
                    {
                        writer.Write("<TD>");
                        writer.Write(temp.GetValue(i).ToString());
                        writer.Write("</TD>");
                    }
                }
                else
                    writer.Write("<TD>" + Data.ToString() + "</TD>");
            }

            else
                writer.Write("<TD>This is a test</TD>");
        }
    }
}

Windows 98, Windows Server 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0

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