如何从 Android 的上下文菜单中删除列表视图对话框项？

Question

我有一个正在显示列表视图的对话框。长按列表上下文菜单中的项目会弹出。现在在上下文菜单中按删除应该删除列表视图中的相应项目。 这是我到目前为止编写的代码...

public class ViewContacts extends Activity {

   List<String> contacts;
   SharedPreferences prefs;
   SharedPreferences.Editor editor;
   ArrayAdapter<String> adapter;
   Dialog dialog;
   ListView lv;
   @Override
   protected void onCreate(Bundle savedInstanceState) {
       // TODO Auto-generated method stub
       super.onCreate(savedInstanceState);
        contacts = new ArrayList<String>();
       dialog = new Dialog(ViewContacts.this);
       dialog.setTitle("My Contacts");
       dialog.setContentView(R.layout.activity_mycontacts);
       dialog.setCancelable(true);

       dialog.show();
        contacts.add("Abc");
        contacts.add("xyx");
        contacts.add("klm");

       lv =(ListView)dialog.findViewById(R.id.lv);
       adapter =new ArrayAdapter<String>(this,R.layout.row,R.id.contacts,contacts);
       lv.setAdapter(adapter);
       registerForContextMenu(lv);
}
@Override
public void onCreateContextMenu(ContextMenu menu, View v,
        ContextMenu.ContextMenuInfo menuInfo) {

        MenuInflater inflater =getMenuInflater();
        inflater.inflate(R.menu.menu_list, menu);

}

@Override
public boolean onContextItemSelected(MenuItem item) {
    // TODO Auto-generated method stub
    AdapterContextMenuInfo info =(AdapterContextMenuInfo) item.getMenuInfo();
    switch (item.getItemId()) {
    case R.id.del_menu:
        contacts.remove(adapter.getItem(info.position));
        adapter.notifyDataSetChanged();
        return true;
    case R.id.can_menu:
       return true;
    default:
        break;
    }
    return super.onOptionsItemSelected(item);
}

}

menu_list.xml 代码：

<?xml version="1.0" encoding="utf-8"?>
  <menu xmlns:android="http://schemas.android.com/apk/res/android" >
       <item android:id="@+id/del_menu"
         android:title="Delete">
       </item>
        <item android:id="@+id/can_menu"
         android:title="Cancel">
       </item>


 </menu>

我的代码没有做任何事情。可能是什么问题？对于这种从列表视图中删除项目的方法有什么建议或替代方法吗？

Answer 1

我通过使用 OnItemlongclicklistener 解决了这个问题。感谢@Dhara Shah 的建议..

这是我的代码..

lv.setOnItemLongClickListener(new OnItemLongClickListener() {

        @Override
        public boolean onItemLongClick(AdapterView<?> arg0, View arg1,
                int position, long id) {
            // TODO Auto-generated method stub

            Intent i = new Intent(ViewContacts.this,Delete_Confirm.class).addFlags(Intent.FLAG_ACTIVITY_NO_HISTORY);
    //I am sending position of listitem in putExtra below//     
            i.putExtra("position", position);
            startActivityForResult(i,CONFIRM);
            return true;

        }
    });

在这个 Delete_Confirm 类中是包含自定义对话框的 Activity，用于从用户那里获取是否删除它的确认..

这就是我的 Delete_Confirm.java 代码：

public class Delete_Confirm extends Activity implements OnClickListener {

Dialog dialog;
Button del,cancel;
int pos;
@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    Bundle bundle = getIntent().getExtras();
    pos = bundle.getInt("position");
    Log.d("msg","position is " + pos); 
    dialog = new Dialog(Delete_Confirm.this);

    dialog.setTitle("My Contacts");
    dialog.setContentView(R.layout.activity_del);
    del = (Button) dialog.findViewById(R.id.del_con);
    cancel = (Button) dialog.findViewById(R.id.no_del_con);
    del.setOnClickListener(this);
    cancel.setOnClickListener(this);
    dialog.setCancelable(true);
    dialog.setOnCancelListener(new DialogInterface.OnCancelListener() {

        @Override
        public void onCancel(DialogInterface arg0) {
            // TODO Auto-generated method stub
            dialog.dismiss();
            finish();
        }
    });
    dialog.show();
}
@Override
public void onClick(View v) {
    // TODO Auto-generated method stub
    switch (v.getId()) {
    case R.id.del_con:
        Intent yes = this.getIntent();
        yes.putExtra("position", pos);
        this.setResult(RESULT_OK,yes);
        finish();
        break;
    case R.id.no_del_con:
        Intent no = this.getIntent();
        this.setResult(RESULT_CANCELED,no);
        finish();
        break;
    default:
        break;
    }
}

现在在 onActivityResult 中，我从 Delete_Confirm.java 的 setResult() 方法中获得用户的选择。

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    // TODO Auto-generated method stub
    super.onActivityResult(requestCode, resultCode, data);
      if(requestCode==CONFIRM){

          if(resultCode==RESULT_OK){
              int posi = data.getIntExtra("position",0);
                  Log.d("msg","positionwa is " + posi);

                  Log.d("msg","Do we reach here?");
                  if(posi==0){
                  contacts.remove(posi);
                  adapter.notifyDataSetChanged();
                  }


                  else if(posi==1){
                      contacts.remove(posi);
                      adapter.notifyDataSetChanged();

                      }


                  else if(posi==2){
                      contacts.remove(posi);
                      adapter.notifyDataSetChanged();

                       }



          }
          if(resultCode==RESULT_CANCELED){
              dialog.dismiss();
              finish();
          }
      }

如果有人遇到同样的问题，我会发布我的答案..

Answer 2

长项目点击监听器有位置。

listView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {

        public boolean onItemLongClick(AdapterView<?> arg0, View v,
                int index, long arg3) {
            // TODO Auto-generated method stub
            // store the position of the item that has to be deleted 
            return true;
        }
}); 

当按下或点击上下文菜单中的删除时，由于您有位置，在这种情况下，从列表中删除该项目，如

list.remove(position);

然后再次致电notifyDatasetChanged()。