I am starting a new HTML5-based ASP.NET Web Application project in Visual Studio 2013, and am having a hard time getting the compiler to recognize valid HTML5 tag attributes within the <asp:TextBox> element. Here is some sample code from a test page:
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="testing_html5.aspx.cs" Inherits="testing_html5" %><!DOCTYPE html><html xmlns="http://www.w3.org/1999/xhtml"><head runat="server"><title></title></head><body><form id="form1" runat="server"><div><asp:TextBox runat="server" ID="tbxTesting" autocomplete="off" placeholder="Test!"></asp:TextBox><input type="text" autocomplete="off" placeholder="Test!" /><textarea placeholder="testing"></textarea><br></div></form></body></html>
And here is the error list that results from this page (I'll replace with an image once I get approved):
You'll notice that the "placeholder" and "autocomplete" attributes appear as invalid attributes for the <asp:TextBox> element, but not for the <input type="text"> elements.
I have my target schema for validation set to check the doctype of the file, and it is correctly identifying the <!DOCTYPE html> as being HTML5, but for some reason, it doesn't like HTML5 attributes in the <asp:TextBox> element, no matter what I
try.
I realize I can just turn off the messages list, but I would much rather be able to get the <asp:TextBox> element to just recognize the valid attributes.
Is there any known way of doing this? Thanks so much.