最后，我自己修复了该问题:

Finally I got fixed it myself:

我的配置文件是

/app/code/local/Revered/Expdlvrydate/etc/config.xml

<?xml version="1.0"?>
<config>
    <modules>
        <Revered_Expdlvrydate>
            <version>0.1.0</version>
        </Revered_Expdlvrydate>
    </modules>
    <global>
    <frontend>
        <layout>
            <updates>
                <expdlvrydate_layout module="Expdlvrydate">
                    <file>expdlvrydate.xml</file>
                </expdlvrydate_layout>
            </updates>
        </layout>
    </frontend>
</config>

我的布局文件是

/app/design/frontend/base/default/layout/expdlvrydate.xml

<?xml version="1.0"?>
<layout version="0.1.0">
    <sales_order_view>
        <reference name="order_items">
            <action method="addItemRender">
                <type>default</type>
                <block>sales/order_item_renderer_default</block>
                <template>revered/expdlvrydate/sales/order/items/renderer/default.phtml</template>
            </action>
        </reference>
    </sales_order_view>
</layout>

我的phtml文件是

/app/design/frontend/base/default/template/revered/sales/order/items/renderer/default.phtml

在项目选项下方添加了以下代码

Added following code below item options

<?php if ($_item = $this->getItem()): ?>
        <?php if ( $_item->getEdeliverydate() != NULL):?>
        <dl class="item-options">
            <dt><?php echo $this->escapeHtml('Expected Delivery Date') ?></dt>
            <dd><?php echo $this->formatDate($_item->getEdeliverydate(), 'long'); ?></dd>
        </dl>
        <?php endif; ?>
    <?php endif; ?>