razor pages create mutliselect dropdown code example
Example: class selector to property in asp net core dropdown
<select data-val="true" data-val-required="The Employee field is required." id="Employee" name="Employee"> <option value=""></option> <optgroup label="IT"> <option value="1">Mike</option> </optgroup> <optgroup label="Sales"> <option value="2">Pete</option> <option value="4">Dean</option> </optgroup> <optgroup label="Admin"> <option value="3">Katy</option> </optgroup></select>