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

Question

我有一个 Android 应用程序。在派生自 ListActivity 的 Activity 之一中，我实现了 OnItemLongClickListener。我想在相关列表项中启用删除按钮，其中 ListItem 已被 LongClicked。我该怎么做？

    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);

Answer 1

.xml

  <Button
  android:id="@+id/imgdelete"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content" 
  android:visibility="invisible"/>

.java

lv.setOnItemLongClickListener(new OnItemLongClickListener() {     

@Override
public boolean onItemLongClick(AdapterView<?> arg0, View view, int arg2, long arg3) {

       view.findViewById(R.id.imgdelete).setVisibility(View.INVISIBLE);
       return false;

 }            

});