android – 如何在ListView onItemLongClick上显示/启用按钮

我有一个 Android应用程序.在我从ListActivity派生的一个Activity中,我实现了OnItemLongClickListener.我想在ListItem已被LongClicked的相关列表项中启用删除按钮.我怎样才能做到这一点？

OnItemLongClickListener listener =  new OnItemLongClickListener(){
        public boolean onItemLongClick(AdapterView<?> av, View v, int position, long id) {
            Account a = null;
            a = (Account) av.getItemAtPosition(position);               
            Toast.makeText(AccountActivity.this, "Long Clicked : " + a.getAccountName(), Toast.LENGTH_LONG).show();

            //instead of the toast, I need to show/enable a button here...
        }
    };
    getListView().setOnItemLongClickListener(listener);

假设您在ListView的行布局中有一个Button,那么您可以将其显示为true`

OnItemLongClickListener listener =  new OnItemLongClickListener(){
    public boolean onItemLongClick(AdapterView<?> av, View v, int position, long id) {
        Account a = null;
        a = (Account) av.getItemAtPosition(position);               
        v.findViewById(R.id.btnid).setVisiBility(View.VISIBLE);
    }
};`