HiddenField.Value is an empty string upon postback inside my custom control
- by Matthew Cox
I have a custom control that has a hidden field. Upon postback I want to obtain the value stored in it, but it's always an empty string. any thoughts?
I am performing client-side manipulation of the hidden field values and have verified in firebug that the fields are correct before issue a post back
Here is the setup:
public class DualListPanel : SWebControl, INamingContainer
{
protected IList<DlpItem> UnassignedList { get; set; }
protected IList<DlpItem> AssignedList { get; set; }
private HiddenField assignedItemsField, unassignedItemsField;
public DualListPanel()
{
CssClass = "DualListPanel";
EnableViewState = true;
}
#region ViewState
protected override void LoadViewState(object savedState)
{
var state = savedState as object[];
UnassignedList = state[0] as List<DlpItem>;
AssignedList = state[1] as List<DlpItem>;
base.LoadViewState(state[2]);
}
protected override object SaveViewState()
{
object[] state = new object[3];
state[0] = UnassignedList;
state[1] = AssignedList;
state[2] = base.SaveViewState();
return state;
}
#endregion
#region WebControl Overrides
protected override void CreateChildControls()
{
assignedItemsField = new HiddenField();
assignedItemsField.ID = "HiddenAssignedItems";
assignedItemsField.EnableViewState = true;
unassignedItemsField = new HiddenField();
unassignedItemsField.ID = "HiddenUnassignedItems";
unassignedItemsField.EnableViewState = true;
Controls.Add(assignedItemsField);
Controls.Add(unassignedItemsField);
base.CreateChildControls();
}
#endregion
#region Item Lists Retrieval
public string GetCommaDelimUnassignedItems()
{
return unassignedItemsField.Value;
}
public string GetCommaDelimAssignedItems()
{
return assignedItemsField.Value;
}
#endregion
}
