Binding to Textbox Maxlength field within repeater - asp.net

Question

Ive got an issue where the MaxLength field doesnt seem to adhere to the value being set in code-behind.
MaxLength='<%#Convert.ToInt32(Eval("AdditionalOptionInfo.MaxFieldLength"))%>'
If I set the MaxLength="10" for example it seems to work fine.
EDIT: Whole code
<asp:Repeater ID="rptList" runat="server">
<HeaderTemplate>
<ul>
</HeaderTemplate>
<ItemTemplate>
<li>
<div class="asdf">
<asp:LinkButton ID="adsf" CssClass="asdf" CommandArgument='<%#Eval("OptionAvailable")%>' runat="server" OnDataBinding="lnkList_OnDataBinding" OnClientClick="contactDetailOptionClick(this); return false;">
<%#Eval("DisplayText")%>
<table class="tbox" runat="server" visible='<%#Eval("IsAdditionalInfoApplicable")%>'>
<tbody>
<tr>
<td>
<asp:Label runat="server" CssClass="asdf" Text='<%#Eval("AdditionalOptionInfo.InstructionText")%>' />
<br />
<asp:TextBox placeholder='<%#Eval("AdditionalOptionInfo.PlaceHolderText")%>' RetainValueAfterPostback="true" ellipsis="true" AutoComplete="Off" runat="server" MaxLength='<%#Convert.ToInt32(Eval("AdditionalOptionInfo.MaxFieldLength"))%>' />
</td>
</tr>
</tbody>
</table>
</asp:LinkButton>
</div>
</li>
</ItemTemplate>
<FooterTemplate>
</ul>
</FooterTemplate>
</asp:Repeater>
My implementation after Andrew's suggestion:
public int GetMaxLength(object additionalOptionInfo)
{
var option = additionalOptionInfo as TypeXYZ<string>;
return option != null ? option.MaxFieldLength : 0;
}

Answer 1

The max lenth eval is still going to be hit if the parent table's visibility is false because all this code is sitting on the front end.
I'd do something like this:
MaxLength='<%# GetMaxLength(Eval("AdditionalOptionInfo.MaxFieldLength"))%>'
public string GetMaxLength(object optionInfo)
{
TypeOfOptionInfo option = (TypeOfOptionInfo) optionInfo;
if (option != null)
{
return optionInfo.MaxFieldLength;
}
else
{
return "0";
}
}