动态添加视图列表视图的每一行

时间:2013-11-08 12:40:03

标签: android performance android-layout android-listview android-linearlayout

我有一个嵌套数组显示在我的Listview中.ListView的每一行都有一个水平LinerLayout到Horizo​​ntalScrollView。

目前我正在使用ViewHolder模式,并在ListView的getView方法中为LinerLayout动态添加视图。

问题是滚动时列表视图滞后..

这是我的自定义适配器类

public class ChannelArrayAdapter extends ArrayAdapter<Kanal> {
Context context;
List<Kanal> list;
List<Program> pList;
LayoutInflater inflator;

public ChannelArrayAdapter(Context context, List<Kanal> lis) {
    super(context, R.layout.channels, lis);
    // TODO Auto-generated constructor stub
    this.list = lis;
    this.context = context;
}

static class ViewHolder {
    ImageView imageView;
    LinearLayout l;
}

static class ProgramHolder {
    TextView programAdi;
    TextView programSaati;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
     ViewHolder viewHolder = null;
    if (convertView == null) {
        inflator = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView = inflator.inflate(R.layout.channels, parent, false);
        viewHolder.imageView = (ImageView) convertView.findViewById(R.id.imageView1);
        viewHolder.l = (LinearLayout) convertView.findViewById(R.id.yayinAkisiLayout);
        convertView.setTag(viewHolder);

    } else {
        viewHolder = (ViewHolder)convertView.getTag();
        viewHolder.l.removeAllViews();
    }

    final Kanal kanal = list.get(position);
    pList = kanal.getKanalProgramListesi();
    viewHolder.imageView.setImageResource(kanal.getResourcesIkonKanal());

    for (Program p : pList) {
        View v = new View(context);
        v.setId(position);
        ProgramHolder pHolder = new ProgramHolder();
        v = inflator.inflate(R.layout.programs, null);          
        pHolder.programSaati = (TextView) v.findViewById(R.id.psaati);
        pHolder.programAdi = (TextView)v.findViewById(R.id.pname);
        pHolder.programAdi.setText(p.getProgramAdi());
        pHolder.programSaati.setText(p.getProgramBaslangic());
        v.setTag(pHolder);
        viewHolder.l.addView(v);
    }

    return convertView;
}

}

2 个答案:

答案 0 :(得分:0)

将holder设为静态类,只需在getView中编辑其字段即可。您的列表视图滞后,因为每次调用getView时都会创建一些新对象 - &gt;每次加载新项目或获得ListView的可见性。

http://www.youtube.com/watch?v=wDBM6wVEO70

这详细解释了如何制作有效的adapter / listView。

答案 1 :(得分:0)

您可以优化这段代码:

ProgramHolder pHolder = new ProgramHolder();
        v = inflator.inflate(R.layout.programs, null);          
        pHolder.programSaati = (TextView) v.findViewById(R.id.psaati);
        pHolder.programAdi = (TextView)v.findViewById(R.id.pname);
        pHolder.programAdi.setText(p.getProgramAdi());
        pHolder.programSaati.setText(p.getProgramBaslangic());
        v.setTag(pHolder);
        viewHolder.l.addView(v);

作为View Holder模式,您应该存储这些布局,也可以存储在静态变量中:

static  ProgramHolder pHolder;

if (pHolder == null) {
    View v = new View(context);
    v = inflator.inflate(R.layout.programs, null);          
    pHolder.programSaati = (TextView) v.findViewById(R.id.psaati);
    pHolder.programAdi = (TextView)v.findViewById(R.id.pname);
}

这里的主要目的是减少使用时间findViewById()。之后,在循环中,您可以创建自定义视图,并根据pHolder分配每个字段。

希望这有帮助:)