直接内联样式呢
wb.InsertHTML("<br/><div style=""text-align: center;""><span style=""width: 20%;display: inline-block;border: 0.2px solid #ddd;vertical-align: middle;""></span><span style=""color: #888;font-size: 16px;"">我是有底线的</span><span style=""width: 20%;display: inline-block;border: 0.2px solid #ddd;vertical-align: middle;""></span></div><br/><br/><br/>")