定义的“aspNetDisabled”类在哪里?NET渲染一个干扰的重复CSS“类”属性?

When I set the "Disabled" property of an ASP.NET TextBox control to false, the final rendered HTML textarea tag (sent to the browser) includes an 'class="aspNetDisabled"' attribute in addition to the 'disabled="disabled"' attribute. Where is the "aspNetDisabled" class defined?When I set the "Disabled" property of an ASP.NE