menu中showAsAction

<!-- How this item should display in the Action Bar, if present. -->
<attr name="showAsAction">
    <!-- Never show this item in an action bar, show it in the overflow menu instead.
         Mutually exclusive with "ifRoom" and "always". -->
    <flag name="never" value="0"/>
    <!-- Show this item in an action bar if there is room for it as determined
         by the system. Favor this option over "always" where possible.
         Mutually exclusive with "never" and "always". -->
    <flag name="ifRoom" value="1"/>
    <!-- Always show this item in an actionbar, even if it would override
         the system's limits of how much stuff to put there. This may make
         your action bar look bad on some screens. In most cases you should
         use "ifRoom" instead. Mutually exclusive with "ifRoom" and "never". -->
    <flag name="always" value="2"/>
    <!-- When this item is shown as an action in the action bar, show a text
         label with it even if it has an icon representation. -->
    <flag name="withText" value="4"/>
    <!-- This item's action view collapses to a normal menu
         item. When expanded, the action view takes over a
         larger segment of its container. -->
    <flag name="collapseActionView" value="8"/>
</attr>

• never
  • 不顯示在界面上，只讓出現在右邊的三個點中
• ifRoom
  • 如果有位置才顯示，不然就出現在右邊的三個點中
• always
  • 始終在actionbar中顯示此項
• withText
  • 這個值使菜單和它的圖標，菜單文本一起顯示
• collapseActionView
  • 菜單中包含摺疊視圖，當展開時，這個視圖將接管其容器的較大部分。