select-menu-off-screen.html - Android社区 - https://www.androidos.net.cn/

<html>
<body>
    <ol>
    <li>Maximize window.</li>
    <li>Click on left menu and make sure whole menu (all of the entries should be completely visible) appears on screen against the left edge of the screen.</li>
    <li>Click on right menuand make sure whole menu (all of the entries should be completely visible) appears on screen against the right edge of the screen.</li>
    </ol>
    <select id="left-select-over" style="margin-left:-50px;">
      <option value="first">First</option>
      <option value="second">Second</option>
      <option value="third">Third</option>
      <option value="fourth">Fourth</option>
    </select>
    <select id="right-select-over" style="float:right; margin-right:-50px;">
      <option value="first">First</option>
      <option value="second">Second</option>
      <option value="third">Third</option>
      <option value="fourth">Fourth</option>
    </select>
</body>
<html>