100分求个思路或是正则表达式什么的,请进!该如何解决

100分求个思路或是正则表达式什么的,请进!
我做的是C#窗口程序,想对http请求的响应解析,读取需要的数据,读取每个<tr>下的第一个<td>的<a>链接的 href属性的值
响应的html文档代码大概的结构如下:

<tr>

  <td></td><td></td><td></td><td></td>

</tr>

<tr>

   <td></td><td></td><td></td><td></td>

</tr>

贴两行真实<tr>的代码出来如下:

  <tr logr="p_0_23219080775431_18974112972167_0">

                    <td class="img"><a target="_blank" href="http://ny.58.com/ershoufang/18974112972167x.shtml">

                        <img alt="" src="http://pic7.58cdn.com.cn/p1/tiny/n_s02391407514652158114.jpg" /></a>

                     </td>

                    <td class="t">

                        <a href="/ershoufang/?key=邓州" target="_blank" class="t1">[二手房]</a><span class="hg">-</span>

                        <a href="http://ny.58.com/ershoufang/18974112972167x.shtml" target="_blank" class="t" title="性价比极高的个人房源出售">性价比极高的个人房源出售

                        </a>

                        <span class='ico biz'>（个人）</span>                    <span class='ico ntu' title=''>[8图]</span>

                        <span name="zaixian_23219080775431"></span>

                        <br />

                        <p class="sub">个人房源。…就医上学…升值空间大，户型设计合理，…看房请提前预约.</p>

                        <p class="abt">

                            <a href="/dengzhou/ershoufang/">邓州</a><span> - </span>

                            <!-- 房产信息中二手房和租房在商圈后增加显示小区 -->

                            <a href="/ershoufang/jh_超高性价比的">超高性价比的</a><span> - </span>

                            今天

                        </p>

                    </td>

                    <td class="pd" style="width: 15%">2室(94)

                    </td>

                    <td class="pd01" style="width: 15%">

                        <b class='pri'>25</b> 万

                    </td>

                </tr>


                <tr logr="p_1_18191348468486_19099111543554_0">

                    <td class="img"><a target="_blank" href="http://ny.58.com/ershoufang/19099111543554x.shtml">

                        <img alt="" src="http://pic8.58cdn.com.cn/p1/tiny/n_s12407409337043876114.jpg" /></a></td>