2

我正在尝试创建一个使用以下代码平滑滚动的列表视图：

 <ListView
        android:id="@+id/list2"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:listSelector="@android:color/transparent" />

// tt 是包含 100 个对象的 x (Object) 数组。

x[] tt= response.getX();

ItemsAdapter myListAdapter = new ItemsAdapter(getActivity(),R.layout.mylist, tt);
// setListAdapter(myListAdapter);
list2.setAdapter(myListAdapter);

// 适配器列表视图

 public class ItemsAdapter extends BaseAdapter {
    Context myContext;
    private int customLayoutId = -1;
    private X[] items;

    public ItemsAdapter(Context context, int resource, X[] x) {

        customLayoutId = resource;
        myContext = context;
        this.items = x;

    }

    public View getView(final int position, View convertView,
            ViewGroup parent) {

        // View row = convertView;

        try {
            LayoutInflater inflator = ((Activity) myContext)
                    .getLayoutInflater();

            xdata= items[position];

            if (convertView == null) {
                // row = inflater.inflate(customLayoutId, null);
                convertView = inflator.inflate(customLayoutId, null);
                DataViewHolder viewHolder1 = null;

                viewHolder1 = new DataViewHolder();

                viewHolder1.numberTV = (TextView) convertView
                        .findViewById(R.id.numberTV);
                viewHolder1.costTV = (TextView) convertView
                        .findViewById(R.id.costTV);
                viewHolder1.reserveButton = (Button) convertView
                        .findViewById(R.id.reserveButton);
                viewHolder1.reserveButton
                        .setBackgroundResource(R.drawable.reserve_button);

                viewHolder1.position = position;

                convertView.setTag(viewHolder1);
            }


            DataViewHolder viewHolder1 = (DataViewHolder) convertView
                    .getTag();


            viewHolder1.numberTV.setText(xdata.getMsisdn());

            viewHolder1.costTV.setText(etrData.getPrice());

            viewHolder1.reserveButton
                    .setOnClickListener(new OnClickListener() {

                        @Override
                        public void onClick(View v) {



                    });

        } catch (Exception e) {
            e.printStackTrace();
        }

        return convertView;
    }

 }

  @Override
    public int getCount() {

        return this.items.length;
    }

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }
}

static class DataViewHolder {
    public TextView numberTV;
    public TextView costTV;
    public Button reserveButton;
    public int position;
}

当我滚动此列表时，应用程序崩溃是 Logcat 中的内容：

07-27 02:50:26.756: I/Choreographer(24450): Skipped 46 frames!  The application may be       doing too much work on its main thread.
07-27 02:50:27.497: I/Choreographer(24450): Skipped 41 frames!  The application may be doing too much work on its main thread.
07-27 02:50:28.698: I/Choreographer(24450): Skipped 32 frames!  The application may be doing too much work on its main thread.

07-27 02:50:34.724: D/dalvikvm(24450): GC_CONCURRENT freed 1120K, 12% free 13993K/15815K, paused 6ms+6ms, total 35ms

07-27 02:50:35.655: I/Choreographer(24450): Skipped 41 frames!  The application may be doing too much work on its main thread.
07-27 02:50:45.685: I/Choreographer(24450): Skipped 58 frames!  The application may be doing too much work on its main thread.
07-27 02:50:46.936: I/Choreographer(24450): Skipped 69 frames!  The application may be doing too much work on its main thread.
07-27 02:50:57.677: I/Choreographer(24450): Skipped 31 frames!  The application may be doing too much work on its main thread.
07-27 02:50:59.639: I/Choreographer(24450): Skipped 53 frames!  The application may be doing too much work on its main thread.
07-27 02:51:03.953: D/TextLayoutCache(24450): Cache value 0x54a260f0 deleted, size = 280
07-27 02:51:03.963: D/TextLayoutCache(24450): Cache value 0x41002fd0 deleted, size = 400
07-27 02:51:03.963: D/TextLayoutCache(24450): Cache value 0x40f05908 deleted, size = 360
07-27 02:51:04.113: D/TextLayoutCache(24450): Cache value 0x413aa480 deleted, size = 384
07-27 02:51:04.123: D/TextLayoutCache(24450): Cache value 0x413a6200 deleted, size = 408

这些错误应该如何处理？我究竟做错了什么？

4

2 回答 2

2

首先，

我认为问题出在您使用时的 getView

LayoutInflater inflator = ((Activity) myContext).getLayoutInflater();

无需将其转换为 (Activity) 并使用该 layoutInflater。

正如我看到的那样，您在适配器的 custructor 中传递了上下文，您可以使用

LayoutInflater inflater = (LayoutInflater) myContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

此外，如果您想正确实现 ViewHolder 模式，您应该这样做：

       DataViewHolder viewHolder1 = null;
       if (convertView == null) {
            // row = inflater.inflate(customLayoutId, null);
            convertView = inflator.inflate(customLayoutId, null);
            viewHolder1 = new DataViewHolder();
            viewHolder1.numberTV = (TextView) convertView.findViewById(R.id.numberTV);
            viewHolder1.costTV = (TextView) convertView.findViewById(R.id.costTV);
            viewHolder1.reserveButton = (Button)convertView.findViewById(R.id.reserveButton);      
            viewHolder1.reserveButton.setBackgroundResource(R.drawable.reserve_button);
            viewHolder1.position = position;
            convertView.setTag(viewHolder1);
        }
        else{
            viewHolder1 = (DataViewHolder) convertView.getTag();
        }

更新：

通常，为了使列表视图更快，您应该尝试使 getView() 简单快速，并且我的意思是您几乎应该使用它来使用预先填充的值将数据打印给用户。

为了做到这一点，您应该正确实现视图模式，并且 永远不要在 getView 中访问数据库或从 Internet 获取值。

在那之后，我可能会在您的代码中找到您的问题的唯一可能原因是，如果方法

xdata.getMsisdn() and etrData.getPrice()

除了获取诸如访问互联网或数据库之类的值之外，还可以在后台做些什么？

于 2013-07-27T00:15:54.527 回答
0

我认为问题可能是模拟器中的错误。您使用的是模拟器还是实际设备？我使用上面描述的 Manos 模式看到了这种行为——很好的提示！-- 包含 20 项硬编码字符串数组。

如果我使用我的 2.3.3 模拟器，也没有问题。如果我使用 2.2.3 或 4.1.1 的实际设备，也没有问题。

于 2013-11-28T19:05:42.983 回答