android – 如何在ListView中处理多个倒计时计时器？

我有一个listview(使用自定义列表适配器),我需要在每一行显示倒计时.

例如,如果我的列表包含4个项目,我将有4行.
在这一点上,我需要处理4个不同的倒计时(每行一个),因为时间不同.

到目前为止,我使用以下方式处理它：在自定义列表适配器中,在getView()方法内部,我创建一个新的CountDownTimer,并在TextView中显示剩余时间.

但是问题是它减慢了很多活动,甚至在最坏的情况下甚至无法正确滚动(因为每次显示一行,都会创建一个新的CountDownTimer).

我搜索了很多更好的解决方案,但没有人满意.

有没有更清洁和更平滑的解决方案来处理listView中的多个倒计时计时器？

谢谢

解决方法

而不是试图显示所有的剩余时间,这个想法是更新可见项目的剩余时间.

请按照以下示例代码,让我知道：

主要活动：

public class MainActivity extends Activity {

private ListView lvItems;
private List<Product> lstProducts;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    lvItems = (ListView) findViewById(R.id.lvItems);
    lstProducts = new ArrayList<>();
    lstProducts.add(new Product("A",System.currentTimeMillis() + 10000));
    lstProducts.add(new Product("B",System.currentTimeMillis() + 20000));
    lstProducts.add(new Product("C",System.currentTimeMillis() + 20000));
    lstProducts.add(new Product("D",System.currentTimeMillis() + 20000));
    lstProducts.add(new Product("E",System.currentTimeMillis() + 20000));
    lstProducts.add(new Product("F",System.currentTimeMillis() + 20000));
    lstProducts.add(new Product("G",System.currentTimeMillis() + 30000));
    lstProducts.add(new Product("H",System.currentTimeMillis() + 20000));
    lstProducts.add(new Product("I",System.currentTimeMillis() + 20000));
    lstProducts.add(new Product("J",System.currentTimeMillis() + 40000));
    lstProducts.add(new Product("K",System.currentTimeMillis() + 20000));
    lstProducts.add(new Product("L",System.currentTimeMillis() + 50000));
    lstProducts.add(new Product("M",System.currentTimeMillis() + 60000));
    lstProducts.add(new Product("N",System.currentTimeMillis() + 20000));
    lstProducts.add(new Product("O",System.currentTimeMillis() + 10000));

    lvItems.setAdapter(new CountdownAdapter(MainActivity.this,lstProducts));
}

private class Product {
    String name;
    long expirationTime;

    public Product(String name,long expirationTime) {
        this.name = name;
        this.expirationTime = expirationTime;
    }
}


public class CountdownAdapter extends ArrayAdapter<Product> {

    private LayoutInflater lf;
    private List<ViewHolder> lstHolders;
    private Handler mHandler = new Handler();
    private Runnable updateRemainingTimeRunnable = new Runnable() {
        @Override
        public void run() {
            synchronized (lstHolders) {
                long currentTime = System.currentTimeMillis();
                for (ViewHolder holder : lstHolders) {
                    holder.updateTimeRemaining(currentTime);
                }
            }
        }
    };

    public CountdownAdapter(Context context,List<Product> objects) {
        super(context,objects);
        lf = LayoutInflater.from(context);
        lstHolders = new ArrayList<>();
        startUpdateTimer();
    }

    private void startUpdateTimer() {
        Timer tmr = new Timer();
        tmr.schedule(new TimerTask() {
            @Override
            public void run() {
                mHandler.post(updateRemainingTimeRunnable);
            }
        },1000,1000);
    }

    @Override
    public View getView(int position,View convertView,ViewGroup parent) {
        ViewHolder holder = null;
        if (convertView == null) {
            holder = new ViewHolder();
            convertView = lf.inflate(R.layout.list_item,parent,false);
            holder.tvProduct = (TextView) convertView.findViewById(R.id.tvProduct);
            holder.tvTimeRemaining = (TextView) convertView.findViewById(R.id.tvTimeRemaining);
            convertView.setTag(holder);
            synchronized (lstHolders) {
                lstHolders.add(holder);
            }
        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        holder.setData(getItem(position));

        return convertView;
    }
}

private class ViewHolder {
    TextView tvProduct;
    TextView tvTimeRemaining;
    Product mProduct;

    public void setData(Product item) {
        mProduct = item;
        tvProduct.setText(item.name);
        updateTimeRemaining(System.currentTimeMillis());
    }

    public void updateTimeRemaining(long currentTime) {
        long timeDiff = mProduct.expirationTime - currentTime;
        if (timeDiff > 0) {
            int seconds = (int) (timeDiff / 1000) % 60;
            int minutes = (int) ((timeDiff / (1000 * 60)) % 60);
            int hours = (int) ((timeDiff / (1000 * 60 * 60)) % 24);
            tvTimeRemaining.setText(hours + " hrs " + minutes + " mins " + seconds + " sec");
        } else {
            tvTimeRemaining.setText("Expired!!");
        }
    }
}
}

activity_main.xml：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">

<ListView
    android:id="@+id/lvItems"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

</RelativeLayout>

list_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:padding="5dp">

<TextView
    android:id="@+id/tvProduct"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="10dp"
    android:text="Product Name"
    android:textSize="16dp"
    android:textStyle="bold" />

<TextView
    android:id="@+id/tvTimeRemaining"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="10dp"
    android:text="Time Remaining : " />

</LinearLayout>

android – 如何在ListView中处理多个倒计时计时器？

解决方法

相关推荐