单击时更改MenuItem可见性 [英] change MenuItem visibility when clicked

问题描述

我正试图隐藏一个MenuItem并在选择第一个时使其他可见.

I'm trying to hide one MenuItem and make another visible when the first is selected.

每个的ID为:

pencil: R.id.button_routines_edit
check mark: R.id.button_routines_edit_done

以下是相关代码:

  private boolean isEditing = false;

  @Override
  public boolean onOptionsItemSelected(MenuItem item) {   
      // Handle item selection
      switch (item.getItemId()) {
      case R.id.button_routines_edit:
            // hide pencil icon, show checkmark
            isEditing = true;
        return true;
      case R.id.button_routines_edit_done:
            // show pencil icon, done editing
            isEditing = false;
        return true;
      default:
          return super.onOptionsItemSelected(item);
      }

  }

  @Override
  public boolean onPrepareOptionsMenu(Menu menu) {
      super.onPrepareOptionsMenu(menu);
      // hide pencil when editing and show check mark
      menu.findItem(R.id.button_routines_edit).setVisible(!isEditing);
      menu.findItem(R.id.button_routines_edit_done).setVisible(isEditing);
      return true;
  }

我的问题是: 选择项目时，选项菜单"不会重新绘制它们.换句话说，第一个未隐藏，第二个未显示.

My problem is: The Options Menu doesn't redraw the items when they're selected. In other words, the first isn't hidden and the second isn't shown.

推荐答案

您需要做的就是调用invalidateOptionsMenu().

All you need to do is call invalidateOptionsMenu().

invalidateOptionsMenu()仅在API中可用11岁以上，除非您使用的是 ActionBarSherlock .

invalidateOptionsMenu() is only available in API 11+, unless you're using ActionBarSherlock.

您遇到了这个问题，因为您的MenuItems基本上显示在ActionBar中.如果将它们放在溢出菜单中，则无需调用invalidateOptionsMenu().

You're having this problem because your MenuItems are show in the ActionBar, basically. If you place them in the overflow menu, you won't need to call invalidateOptionsMenu().

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