ios8.4 webview svg操作问题

<aside class="evaluate-side btn" style="display:none;">
    <div class="center">
        <svg class="circle-line" viewBox="0 0 32 32">
            <circle class="cake" r="16" cx="16" cy="16"></circle>
            <circle class="mask" r="12" cx="16" cy="16"> </circle>
            <text dx="16" dy="-17">作答率</text>
            <text dx="16" dy="-12"><tspan fill="#ffa836">..</tspan> / <tspan>..</tspan></text>
        </svg>
            
        <a class="button end" href="javascript:;">结束评测</a>
    </div>
</aside>

sText = eBoxs[1].getElementsByTagName(‘text‘)[1].children; // undefined

sText = eBoxs[1].getElementsByTagName(‘text‘)[1].getElementsByTagName(‘tspan‘),