如何访问由 arrayadapter 生成的列表视图项

Question

我已将我的应用程序绑定到 Firebase 数据库，并且在能够显示它们之后，我还希望能够选择它们并访问它们的 textview 值。但是 .getValue() 不适用于视图。我知道我的代码非常混乱，我的选择器只能以一种方式工作，但你能帮我找出发生了什么吗？我将添加一个屏幕截图以使事情更清楚。在单击其中一项 int num = Integer.parseInt(text) 时会出现错误，并且应用程序将崩溃，因为我从视图中获得的值是“Android.widget ...”，而不是我想要的. 截图图片：

Orders.java

public class Orders extends ActionBarActivity {
    public final static String TOTAL_SUM = "com.nordscript.checkmate.SUM";

// Declare the UI components
    private ListView foodList;

    // Declare an ArrayAdapter that we use to join the data set and the ListView
    // is the way of type safe, means you only can pass Strings to this array
    //Anyway ArrayAdapter supports only TextView
    private ArrayAdapter arrayAdapter;

    private Firebase ref;
    private Orders activ;
    private ArrayList<String> dishes;
    public int total;

@Override
protected void onCreate(Bundle savedInstanceState) {
    activ = this;
    dishes = new ArrayList<String>(20);

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_orders);

 // Initialize the UI components
    foodList = (ListView)findViewById(R.id.listView1);

    // Create a reference to a Firebase location
    ref = new Firebase("https://xxxxxxxxxx.firebaseio-demo.com/Restaurants/Restaurant 2/Tables/Table 2/Orders");

    // Read data and react to changes
    ref.addChildEventListener(new ChildEventListener() {
          @Override
          public void onChildAdded(DataSnapshot snapshot, String previousChildName) {
            Map s = snapshot.getValue(Map.class);
            dishes.add(snapshot.getName() + "  " + ((Map)snapshot.getValue(Map.class)).get("Price"));
            Log.i("Test", dishes.toString());
            arrayAdapter = new ArrayAdapter(activ, android.R.layout.simple_list_item_1, dishes.toArray());

            // By using setAdapter method, you plugged the ListView with adapter
            foodList.setAdapter(arrayAdapter);
          }

          @Override public void onChildChanged(DataSnapshot snapshot, String previousChildName) { }

          @Override public void onChildRemoved(DataSnapshot snapshot) {
            Map s = snapshot.getValue(Map.class);
            dishes.remove(snapshot.getName() + "  " + ((Map)snapshot.getValue(Map.class)).get("Price"));
            Log.i("Test", dishes.toString());
            arrayAdapter = new ArrayAdapter(activ, android.R.layout.simple_list_item_1, dishes.toArray());

            // By using setAdapter method, you plugged the ListView with adapter
            foodList.setAdapter(arrayAdapter);
          }

          @Override public void onChildMoved(DataSnapshot snapshot, String previousChildName) { }

          @Override
          public void onCancelled(FirebaseError arg0) { }
    });

    foodList.setOnItemClickListener(new OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

            view.setBackgroundColor(Color.GREEN);
            String text = view.toString();
            text.replaceAll("[^\\d.]", "");
            int num = Integer.parseInt(text);
            total += num;
        }
    });
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.orders, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

public void toPayment(View view) {
    Intent pay = new Intent(this, PaymentMethod.class);
    pay.putExtra(TOTAL_SUM, total);
    startActivity(pay);
}


}

Answer 1

我从你的问题中了解到：假设当你点击第三个项目，即“pudding 8”时，你想要这个值“pudding 8”（textview 值）。正确的？？ 如果是这样，那么您只需要从 ArrayList 中获取值，然后借助 setOnItemClickListener 中的 position 属性首先传递给适配器，如下所示：

foodList.setOnItemClickListener(new OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

            view.setBackgroundColor(Color.GREEN);

            String text = dishes.get(position);
            // do what you want to do with this value.

        }
    });

Answer 2

像这样改变你的 onClickListener()：

foodList.setOnItemClickListener(new OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

        view.setBackgroundColor(Color.GREEN);
        String text = (String)parent.getItemAtPosition(position);
        text.replaceAll("[^\\d.]", "");
        int num = Integer.parseInt(text);
        total += num;
    }
});

或者您可以使用SimpleAdapter 在单独的xml 布局中使用两个文本视图分别显示字符串和整数值。使用它，您可以更好地获取 onclick() 的值。

Answer 3

您需要获取该特定视图的文本，view.getText().toString();

foodList.setOnItemClickListener(new OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

            view.setBackgroundColor(Color.GREEN);
            String text = view.getText().toString();
            text.replaceAll("[^\\d.]", "");
            int num = Integer.parseInt(text);
            total += num;
        }
    });

Answer 4

这可能对你有帮助，但这是不好的方式：

foodList.setOnItemClickListener(new OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

            String item = (String) arrayAdapter.getItem(position);
            String[] split = item.split(" ");
            int num = Integer.parseInt(split[1]);
            total += num;
        }
    });

但是很冲动……

对于我来说，你需要扩展适配器，将你的自定义项目收集到其中，点击后获取它并获取你需要的整数值。

Answer 5

我知道这可能为时已晚，但希望如此 帮助正在寻找具有多个值的自定义 ArrayAdapter 的类似解决方案的人。

lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

            ListItems item = (ListItems) parent.getItemAtPosition(position);
            System.out.println("Item: "+item.getName());
        }
    });