javascript - 需要时突出显示带有红色边框的文本框

Question

我正在使用 css 在需要时突出显示带有红色边框的文本框

.garbage[style*=inline] + input,
.garbage[style*=inline] + select,
.garbage[style*=inline] + textarea {
    background-color: #ffcccc;
    border: 1px solid #ff0000;
}

<asp:RequiredFieldValidator ID="RequiredFieldValidator1" ControlToValidate="Txt_fullname" runat="server" ErrorMessage="RequiredFieldValidator"  class="garbage" SetFocusOnError="true" ValidationGroup="submit" Display="Dynamic">Type this field please.</asp:RequiredFieldValidator>
                                
<asp:TextBox   ID="Txt_fullname" runat="server" ></asp:TextBox>
                                
<asp:Button ID="Btn_submit" runat="server"  Text="submit form" CausesValidation="true" ValidationGroup="submit" 
                                   onclick="Btn_submit_Click"  />

问题是在我点击文本框之前，css 不适用

Answer 1

使用 CSS:

:required {
  border-color: red;
}