Here's the setup -

I have a custom webcontrol that is derived directly from System.Web.UI.WebControls.WebControl.  In PreRender(), I check a local variable for some data.  If the variable is empty, I call a function to generate some data.  I then store the data in the local variable.  The data is later persisted to the ViewState via SaveViewState().  I overrode LoadViewState() in such a way that, after every postback, the function should reload the data from the ViewState and store it in the local variable. 

Here's the problem -

LoadViewState never fires, ever, no matter how many times the page is posted back!  As a result, my local variable remains empty, and I must regenerate the data every time.  Why is this happening?  SaveViewState, on the other hand, goes off without a hitch.

Some details -

This control does not have any input elements.  All it does is display data from the overriden Render() method.

protected override void LoadViewState(object savedState)

{

base.LoadViewState (savedState);

}

with a breakpoint on the base.LoadViewState line, but it never reaches it.

cakewalkr7 wrote:

Did you get this figured out because I'm running into the same problem.  I just have... protected override void LoadViewState(object savedState) { base.LoadViewState (savedState); } with a breakpoint on the base.LoadViewState line, but it never reaches it.

namespace WebPEQ.Controls

/// <summary>

/// Summary description for RangeGroup.

/// </summary>

public class RangeGroup : System.Web.UI.WebControls.WebControl, IAnswer, INamingContainer

private string[] _answers;

private HorizontalAlign _horAlign = HorizontalAlign.Left;

private VerticalAlign _vertAlign = VerticalAlign.Top;

private Alignment _placement = Alignment.Left;

private System.Web.UI.WebControls.Table OutputTable;

private bool _required = false;

private string _errMessage = string.Empty;

private System.Collections.ArrayList AnswerRadios;

#region Constructor

public RangeGroup(string strAnswers)

OutputTable = new Table();

#region Ranges

//this is the only thing that I need to save to viewstate

public string[] Answers

get{

return _answers;

set

if (value != null && value.Length > 0)

_answers = new string[value.Length];

value.CopyTo(_answers, 0);

AnswerRadios = new System.Collections.ArrayList();

for (int i = 0; i < _answers.Length; i++)

AnswerRadios.Add(new RadioButton());

#region Properties

public string Css

get

return OutputTable.CssClass;

set{

OutputTable.CssClass = value.Trim();

public bool Required

set{

_required = value;

get{

return _required;

public string ErrorMessage

set{

_errMessage = value.Trim();

get{

return _errMessage;

#region Alignment Properties

public VerticalAlign VAlign

set

_vertAlign = value;

public HorizontalAlign TextAlign

set

_horAlign = value;

public Alignment TextPlacement

set

_placement = value;

#region Render

/// <summary>

/// Render this control to the output parameter specified.

/// </summary>

/// <param name="output"> The HTML writer to write out to </param>

protected override void Render(HtmlTextWriter output)

switch (_placement)

case Alignment.Bottom:

BuildVerticalTable(false);

break;

case Alignment.Left:

BuildHorizontalTable(true);

break;

case Alignment.Right:

BuildHorizontalTable(false);

break;

default:

BuildVerticalTable(true);

break;

this.Controls.Add(OutputTable);

#region BuildHorizontalTable

private void BuildHorizontalTable(bool TextOnLeft)

for (int i = 0; i < this._answers.Length; i++)

TableRow row = new TableRow();

TableCell c1 = new TableCell();

TableCell c2 = new TableCell();

if (TextOnLeft)

c1.Text = this._answers.ToString().Trim();

r.GroupName = this.ID;

r.EnableViewState = true;

//r.Checked = i==0?true:false;

else

RadioButton radio = new RadioButton();

r.GroupName = this.ID;

r.EnableViewState = true;

//r.Checked = i==0?true:false;

c2.Text = this._answers.ToString().Trim();

c1.HorizontalAlign = this._horAlign;

c2.HorizontalAlign = this._horAlign;

#region BuildVerticalTable

private void BuildVerticalTable(bool TextOnTop)

TableRow TextRow = new TableRow();

TableRow RadioRow = new TableRow();

for (int i = 0; i < this._answers.Length; i++)

TableCell c = new TableCell();

c.VerticalAlign = this._vertAlign;

c.HorizontalAlign = this._horAlign;

c.Dispose(); c = null;

c = new TableCell();

c.VerticalAlign = this._vertAlign;

c.HorizontalAlign = this._horAlign;

r.EnableViewState = true;

r.GroupName = this.ID;

//r.Checked = i==0?true:false;

c.Dispose(); c = null;

if (TextOnTop)

else

#region Validate

public bool Validate()

if (_required)

int SelectedCount = 0;

for (int i =0; i < AnswerRadios.Count; i++)

RadioButton r = AnswerRadios as RadioButton;

if (r.Checked)

break;

if (SelectedCount == 0)

TableRow row = new TableRow();

TableCell c = new TableCell();

if (_errMessage != string.Empty)

else

return false;

else

return true;

else

return true;

protected override void LoadViewState(object savedState)

base.LoadViewState (savedState);

protected override object SaveViewState()
{ 
   object objSaved = base.SaveViewState();

   this.ViewState[this.ID+"_output"]=this.m_strOut;
   this.ViewState[this.ID+"_error"]=this.m_strErr; 

   return objSaved;
}

My mistake was in following the "convention" of always chaining to the base method as the first line in the method.  However, in this case, this is something that you don't want to do.  My corrected code is as follows  :

protected override object SaveViewState()
{ 
   this.ViewState[this.ID+"_output"]=this.m_strOut;
   this.ViewState[this.ID+"_error"]=this.m_strErr; 
   
   return base.SaveViewState();
}

protected override void Render(HtmlTextWriter output)

this.Controls.Add(OutputTable);

Okay, I rewrote part of the code and moved the this.Controls.Add(OutputTable) to my CreateChildControls method.  However, it's still not holding it's state.  Do I need to override the SaveViewState and the LoadViewState methods?  If so, I'm unclear on how I go about saving and loading the view state with my radio objects.  Can anyone offer some code help?  Thanks!

namespace WebPEQ.Controls
{
	/// 
	/// Summary description for RangeGroup.
	/// 
	[DefaultProperty("ID"), 
		ToolboxData("<{0}:RangeGroup runat=server>")]
	public class RangeGroup : System.Web.UI.WebControls.WebControl, IAnswer, INamingContainer
	{
		private string[] _answers;
		private HorizontalAlign _horAlign = HorizontalAlign.Left;
		private VerticalAlign _vertAlign = VerticalAlign.Top;
		private Alignment _placement = Alignment.Left;
		private System.Web.UI.WebControls.Table OutputTable;
		private bool _required = false;
		private string  _errMessage = string.Empty;
		private System.Collections.ArrayList AnswerRadios;

		#region Constructor
		public RangeGroup(string[] Answers)
		{
			OutputTable = new Table();
			_answers = Answers;
			AnswerRadios = new System.Collections.ArrayList(_answers.Length);
		}
		#endregion
		protected override void CreateChildControls()
		{
			this.Controls.Add(OutputTable);
			for (int i = 0; i < _answers.Length; i++)
				AnswerRadios.Add(new RadioButton());
			base.CreateChildControls ();
		}

		#region Properties
		public string Css
		{
			get
			{
					return OutputTable.CssClass;
			}
			set{
				OutputTable.CssClass = value.Trim();
			}
		}

		public bool Required
		{
			set{ 
				_required = value;
			}
			get{ 			
					return _required;
			}
		}


		public string ErrorMessage 
		{
			set{
				_errMessage = value.Trim();
			}
			get{ 
					return _errMessage;
			}
		}


		#region Alignment Properties
		public VerticalAlign VAlign
		{
			set 
			{
				_vertAlign = value;
			}
		}

		public HorizontalAlign TextAlign
		{
			set 
			{
				_horAlign = value;
			}
		}

		public Alignment TextPlacement
		{
			set
			{
				_placement = value;
			}
		}
		#endregion
		#endregion

		#region Render
		///  
		/// Render this control to the output parameter specified.
		/// 
		///  The HTML writer to write out to 
		protected override void Render(HtmlTextWriter output)
		{
			switch (_placement)
			{
				case Alignment.Bottom:
					BuildVerticalTable(false);
					break;
				case Alignment.Left:
					BuildHorizontalTable(true);
					break;
				case Alignment.Right:
					BuildHorizontalTable(false);
					break;
				default:
					BuildVerticalTable(true);
					break;
			}

			OutputTable.RenderControl(output);
		}
		#endregion

		#region BuildHorizontalTable
		private void BuildHorizontalTable(bool TextOnLeft)
		{
			

			for (int i = 0; i < this._answers.Length; i++)
			{
				TableRow row = new TableRow();
				TableCell c1 = new TableCell();
				TableCell c2 = new TableCell();

				if (TextOnLeft)
				{
					c1.Text = _answers.ToString().Trim();
					RadioButton r = (RadioButton)AnswerRadios; 
					c2.Controls.Add(r);
					r.GroupName = this.ID;
					r.EnableViewState = true;
				}
				else
				{
					RadioButton radio = new RadioButton();
					RadioButton r = (RadioButton)AnswerRadios;
					c1.Controls.Add(r);
					r.GroupName = this.ID;
					r.EnableViewState = true;
					c2.Text = _answers.ToString().Trim();
				}

				c1.VerticalAlign = _vertAlign;
				c1.HorizontalAlign = this._horAlign;
				c2.VerticalAlign = _vertAlign;
				c2.HorizontalAlign = this._horAlign;
				row.Cells.Add(c1);
				row.Cells.Add(c2);

				OutputTable.Rows.Add(row);
			}
		}
		#endregion

		#region BuildVerticalTable
		private void BuildVerticalTable(bool TextOnTop)
		{
			TableRow TextRow = new TableRow();
			TableRow RadioRow = new TableRow();

			for (int i = 0; i < this._answers.Length; i++)
			{
				TableCell c = new TableCell();
				c.VerticalAlign = _vertAlign;
				c.HorizontalAlign = _horAlign;
				c.Text = _answers.ToString().Trim();
				TextRow.Cells.Add(c);
				c.Dispose(); c = null;

				c = new TableCell();
				c.VerticalAlign = _vertAlign;
				c.HorizontalAlign = _horAlign;
				RadioButton r = (RadioButton)AnswerRadios;
				c.Controls.Add(r);
				r.EnableViewState = true;
				r.GroupName = this.ID;
				RadioRow.Cells.Add(c);
				c.Dispose(); c = null;
			}

			if (TextOnTop)									
			{
				OutputTable.Rows.Add(TextRow);
				OutputTable.Rows.Add(RadioRow);
			}
			else
			{
				OutputTable.Rows.Add(RadioRow);
				OutputTable.Rows.Add(TextRow);
			}
		}
		#endregion



	
	}
}

		protected override void CreateChildControls()
		{
			this.Controls.Add(OutputTable);
			for (int i = 0; i < _answers.Length; i++)
				AnswerRadios.Add(new RadioButton());
			base.CreateChildControls ();
 			switch (_placement)
			{
				case Alignment.Bottom:
					BuildVerticalTable(false);
					break;
				case Alignment.Left:
					BuildHorizontalTable(true);
					break;
				case Alignment.Right:
					BuildHorizontalTable(false);
					break;
				default:
					BuildVerticalTable(true);
					break;
			}
		}

...so that it added all the controls to the control in that method and now it's keeping state fine.