问gridView.setMultiChoiceModeListener在安卓应用程序中不起作用

EN

class MySitesActivity : AppCompatActivity() {

    val REQUEST_CODE = 3
    private val TAG = "MySitesActivity"
    lateinit var gridView: GridView
    lateinit var siteAdapter:BaseAdapter
    lateinit var sites:ArrayList<Site>
    lateinit var actionBarObject:ActionBar


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_my_sites)
        setSupportActionBar(findViewById(R.id.my_toolbar))

        sites = ArrayList(db.appDao().getAllSites()) //From Database
        gridView = findViewById<View>(R.id.gridview) as GridView
        siteAdapter = SitesAdapter(this@MySitesActivity, sites)
        gridView.adapter = siteAdapter
        gridView.choiceMode = GridView.CHOICE_MODE_MULTIPLE // CAN DO IN XML
        actionBarObject = supportActionBar!!
        actionBarObject.setDisplayHomeAsUpEnabled(true)


        Log.d(TAG, "* Setting MultiChoiceModeListener *")
        gridView.setMultiChoiceModeListener(object : AbsListView.MultiChoiceModeListener {

            override fun onItemCheckedStateChanged(mode: ActionMode, position: Int,
                                          id: Long, checked: Boolean) {
                // Here you can do something when items are selected/de-selected,
                // such as update the title in the CAB
            }

            override fun onActionItemClicked(mode: ActionMode, item: MenuItem): Boolean {
                // Respond to clicks on the actions in the CAB
                return false
            }

            override fun onCreateActionMode(mode: ActionMode, menu: Menu): Boolean {
                // Inflate the menu for the CAB
                Log.d(TAG,"Inflating menu")
                mode.menuInflater.inflate(R.menu.delete_menu, menu)
                return true
            }

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

            override fun onPrepareActionMode(mode: ActionMode, menu: Menu): Boolean {
                // Here you can perform updates to the CAB due to
                // an invalidate() request
                return false
            }
        })
}


}