Java 新的邮件选择工具栏，如Gmail

在Android Gmail应用程序中，当选择一封或多封电子邮件时，工具栏将变为白色背景，并带有后退按钮、删除按钮等

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我如何在Android L中实现同样的功能？我知道如何在新活动中添加后退按钮（getSupportActionBar（）.setDisplayHomeAsUpEnabled（true）），但找不到此按钮。

您可以找到指南

对于ListView或GridView，您可以在ListView或GridView中搜索启用批上下文操作的

，例如下面的示例

ListView listView = getListView();
listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE_MODAL);
listView.setMultiChoiceModeListener(new MultiChoiceModeListener() {

    @Override
    public void onItemCheckedStateChanged(ActionMode mode, int position,
                                          long id, boolean checked) {
        // Here you can do something when items are selected/de-selected,
        // such as update the title in the CAB
    }

    @Override
    public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
        // Respond to clicks on the actions in the CAB
        switch (item.getItemId()) {
            case R.id.menu_delete:
                deleteSelectedItems();
                mode.finish(); // Action picked, so close the CAB
                return true;
            default:
                return false;
        }
    }

    @Override
    public boolean onCreateActionMode(ActionMode mode, Menu menu) {
        // Inflate the menu for the CAB
        MenuInflater inflater = mode.getMenuInflater();
        inflater.inflate(R.menu.context, menu);
        return true;
    }

    @Override
    public void onDestroyActionMode(ActionMode mode) {
        // Here you can make any necessary updates to the activity when
        // the CAB is removed. By default, selected items are deselected/unchecked.
    }

    @Override
    public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
        // Here you can perform updates to the CAB due to
        // an invalidate() request
        return false;
    }
});

你的意思是完全正确的吗。谢谢请输入这个作为答案。