gwt – HTML上下文中发现的小部件是什么错误

在HTML上下文中找到小部件

这是一个它抱怨的xml片段：

<!-- ... -->
    <g:HTML ui:field="localPanel">

    <fieldset>
        <legend>Local</legend>
        <label for="btn" >BTN:</label><input type="text" ui:field="btn" class="txtbx numeric" maxlength="10" name='btn'/>
        <label for="stdprt">SDT PRT:</label><input type="text" ui:field="stdprt" class="txtbx" readonly="readonly" name='stdPrt'/>
        <label for="rateArea">Rate Area:</label><input type="text" ui:field="ratearea" class="txtbx" readonly="readonly" name='rateArea'/>
        <br/>
        <label for="deleteDigits">delete Digits:</label><g:ListBox ui:field='deletedigs' class="dropdownbx" name='deleteDigits'/>
    </fieldset>
    </g:HTML>
    <g:Button ui:field="submit2">Submit</g:Button>
    </g:HTMLPanel>