ActionItemBadge

介绍：

一个方便你让你在actionbar上显示数字提示的库（这种效果称为badge ）。其实现原理是利用了menu菜单资源文件属性actionLayout

运行效果：

使用说明：

按照正常方式创建一个menu.xml ，同事需要添加actionLayout，为了总是让这个菜单项显示出来，添加上showAsAction=``"always"。

<item
        android:id="@+id/item_samplebadge"
        android:actionLayout="@layout/menu_badge"
        android:showAsAction="always"
        android:title="@string/sample_1"/>

activity中

重写onCreateOptionsMenu

@Override
   public boolean onCreateOptionsMenu(Menu menu) {
       // Inflate the menu; this adds items to the action bar if it is present.
       getMenuInflater().inflate(R.menu.main, menu);
   //you can add some logic (hide it if the count == 0)
       if (badgeCount > 0) {
           ActionItemBadge.update(this, menu.findItem(R.id.item_samplebadge), Iconify.IconValue.fa_android, ActionItemBadge.BadgeStyle.DARKGREY, badgeCount);
       } else {
           ActionItemBadge.hide(menu.findItem(R.id.item_samplebadge));
       }
   //If you want to add your ActionItem programmatically you can do this too. You do the following:
       new ActionItemBadge.Add().act(this).menu(menu).title(R.string.sample_2).itemDetails(0, SAMPLE2_ID, 1).showAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS).build(ActionItemBadge.BadgeStyle.BLUE_LARGE, 1);
       return true;
   }

如果你想在用户点击菜单项之后重新更新badge显示的数目，那么在onOptionsItemSelected中调用invalidateOptionsMenu方法：

@Override
  public boolean onOptionsItemSelected(MenuItem item) {
      int id = item.getItemId();
      if (id == R.id.item_samplebadge) {
          Toast.makeText(this, R.string.sample_3, Toast.LENGTH_SHORT).show();
          badgeCount--;
          invalidateOptionsMenu();
          return true;
      } else if (id == SAMPLE2_ID) {
          Toast.makeText(this, R.string.sample_4, Toast.LENGTH_SHORT).show();
      }
      return super.onOptionsItemSelected(item);
  }