navigation/pages/feedback/feedback.wxml

<view>
    <view class="feedback-title">
        <text>*标题：</text>
        <input class="feedback-title-input" type="text" maxlength="20" placeholder-style="color:#D3D3D3" placeholder="请输入标题" bindinput="getTitle" />
        <view class="warning">
            <view wx:if="{{feedbackTitleLength >= 20}}">
                <text class="warningTitle">注意：标题长度（含标点符号）不能超过20字</text>
            </view>
        </view>
    </view>
    <view class="feedback-title">
        <text>*详细内容：</text>
        <textarea class="feedback-content-input" maxlength="500" placeholder-style="color:#D3D3D3" placeholder="请输入您需要反馈的详细内容" bindinput="getContent" />
        <view class="warning">
            <view wx:if="{{feedbackContentLength >= 500}}">
                <text class="warningTitle">注意：输入的内容（含标点符号）不能超过500字</text>
            </view>
        </view>
    </view>
    <view>
        <view>联系方式：</view>
        <input class="feedback-title-input" type="number" placeholder="请输入您的手机号码" placeholder-style="color:#D3D3D3" bindinput="getPhoneNum"/>
    </view>
    <view>
        <button class="submitBtn" type="primary" bindtap="toSubmit">提交</button>
    </view>
</view>