Why does AjaxControlToolkit TabContainer render all custom control markup properties?

This is a strange one to explain but hope I make sense.

Our organisation has a library of custom controls that we use in our solutions. One example of these controls is a textbox combined with a set of validators which can be configured appropriately by its properties set in the markup.

I now have a problem when using this control in (which I beleive to have narrowed it down) a TabContainer.

If I wanted to use the following markup in the container:

<scc:TextBox ID="txtEmailAddr" runat="server" CssClass="input EmailAddress" EnforceEntry="EmailAddress" ErrorMessage_RequiredFieldNotCompleted="" ErrorMessage_ShowExclamation="true" MaxLength="150" ShowErrorMessageBelow="false" Label="Email Address " />

When I save or reload the .aspx markup it then renders the following markup for the same control:

<scc:TextBox ID="txtEmailAddr" runat="server" CssClass="input EmailAddress" EnforceEntry="EmailAddress" ErrorMessage_RequiredFieldNotCompleted="" ErrorMessage_ShowExclamation="True" MaxLength="150" ShowErrorMessageBelow="False" Label="Email Address " ClientSidePreventInvalidChars="True" EnableClientScript="True" EnfoceOnPaste="False" EnforceMaxLengthWithRXOnMultiline="True" EnforceOnPaste="False" EnforceSpaceInPostcode="True" 开发者_如何学Go ErrorMessage_InvalidFormat="Email Address : Please enter a valid email address" ErrorMessage_NumericValueInvalidOrOutOfRange="Email Address requires a number to be entered in the range to ." GuidanceText="" GuidanceText_RenderInMouseoverPanel="False" JavascriptURL="~/Include/TextBoxMaximumLength.js" LabelBold="False" LabelCSSClass="" MaxValue="9999999" MinValue="-9999999" Read_Only="False" RememberAnswer="False" RenderInParagraphs="True" RenderRequiredTextForRequiredFields="True" Required="True" RequiredField_InitialValue="" Rows="0" ShowMaxLength="False" Text="" TextBox_TabIndex="0" TextboxSkinID="" TextMode="SingleLine" TooltipPopup_BodyText="" TooltipPopup_TooltipText="(guidance)" ValidationGroup="" ValidationExpression="" />

This would not be a problem other than the properties that are now being rendered in the markup are overriding default functionality of the actual control. In this case the default Email Address regular expression is being ignored because the property 'ValidationExpression' is being set to an empty string!

Again I could place the default regex in that property, but I would just like to understand why the markup is behaving in this manner?

Thanks.

Get the code for the AjaxContolToolkit and step through it to see why all properties are rendered. You can adjust that code as you need and compile the dll and use that. From personal experience, that is the only way I have found use for the Toolkit because of behaviors like you describe.