列表视图中的页脚按钮，如何从自定义列表适配器中获取值

Posted 2023-05-07

【中文标题】列表视图中的页脚按钮，如何从自定义列表适配器中获取值

【英文标题】：Footer button in listview, how to get value from custom list adapter

【发布时间】：2016-03-02 11:19:13

【问题描述】：

我在每一行都有一个带有切换按钮的列表视图。我将检查开关的总和存储在变量中。在我启动自定义适配器的 MainActivity 中，我想获得检查开关的总和。那么如何将值从自定义适配器传递给父活动？在 listview 的页脚中，我有一个按钮“Dalej”，我在 MainActivity 中创建了它，并希望在用户单击它时从适配器获取值（这个总和）？

 protected void onCreate(Bundle savedInstanceState) 
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_cardio);
    String[] cardio_1 = getResources().getStringArray(R.array.cardio_1);
    ListView listView = (ListView) findViewById(R.id.listView);

    View footer = getLayoutInflater().inflate(R.layout.cardio_footer, null);
    listView.addFooterView(footer);
    ListAdapter listAdapter = new Adapter_cardio(this, cardio_1);
    cardio.addAll(Arrays.asList(cardio_1))
    listView.setAdapter(listAdapter);

    final Button button = (Button) findViewById(R.id.button);
    button.setOnClickListener(new View.OnClickListener() 
        public void onClick(View v) 

    );

---

适配器

   public Adapter_cardio(Context context,  String[] cardios ) 

    super(context, R.layout.cardio_row, cardios);
    this.context = context;
    inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    Log.d("TAG", "tessst1");
    zaznaczone = new ArrayList();


public String suma(String sum) 
    return sum;

@Override
public View getView(final int position, View convertView, ViewGroup parent) 
    final ViewHolder holder;
    String pytanie = getItem(position);


    if (convertView==null)
        convertView = inflater.inflate(R.layout.cardio_row, null);
        holder = new ViewHolder();
        holder.question = (TextView) convertView.findViewById(R.id.question);
        holder.s = (Switch)convertView.findViewById(R.id.switch1);
        convertView.setTag(holder);
    
    else
        holder = (ViewHolder) convertView.getTag();
    
    holder.question.setText(pytanie);
    //Model_cardio question = getItem(position);
    //final boolean doCheck = (position == 4) || (position == 5);


    holder.s.setTag(position);
    holder.s.setOnCheckedChangeListener(null);
    if (zaznaczone.contains(position) )
    
        holder.s.setChecked(true);
    
    else
    
        holder.s.setChecked(false);
    

    holder.s.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() 
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) 
            if (isChecked) 
                zaznaczone.add((Integer) buttonView.getTag());
             else 
                zaznaczone.remove((Integer) buttonView.getTag());
            

        
    );
    sum = zaznaczone.size();
    String x = "2";
    Log.d("TAG_Switch_all", "suma = " + sum);

    return convertView;

【参考方案1】：

想在用户点击时从适配器获得价值（这个总和）？

创建一个方法为public，它从Adapter_cardio类返回sum：

public int getSum()

 return zaznaczone.size();

并在按钮单击时调用getSum 方法，使用listAdapter 对象作为：

public void onClick(View v) 
     Log.d("TAG_Switch_all", "suma = " + ((Adapter_cardio)listAdapter).getSum());
 

如果 listAdapter 在 onClick 方法中不可访问，则将其声明为 final