Question

我正在使用此代码

处理简单的List视图

public class RadioDemoActivity extends Activity {
ArrayList<String> list = new ArrayList<String>();
MyListAdapter mla;
ListView lv;
int position = -1;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    lv = (ListView) findViewById(R.id.listView1);

    list.add("one");
    list.add("two");
    list.add("three");
    list.add("four");
    list.add("five");
    list.add("six");
    list.add("seven");
    list.add("eight");
    list.add("nine");
    list.add("ten");
    list.add("eleven");
    list.add("twelve");
    list.add("thirteen");
    list.add("fourteen");
    list.add("fifteen");
    list.add("sixteen");
    list.add("seventeen");
    list.add("eightteen");
    list.add("nineteen");
    list.add("twenty");

    mla = new MyListAdapter(this);
    lv.setAdapter(mla);

}


public class MyListAdapter extends BaseAdapter {
    private LayoutInflater mInflater;

    public MyListAdapter(Context context) {
        mInflater = LayoutInflater.from(context);

    }

    public int getCount() {
        return list.size();
    }

    public Object getItem(int position) {
        return position;
    }

    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        if (convertView == null) {
            convertView = mInflater.inflate(R.layout.cust_list, null);

            TextView tv = (TextView)convertView.findViewById(R.id.txt_title);
            ImageView iv = (ImageView)convertView.findViewById(R.id.imageView1);
            tv.setText(list.get(position));
            Log.v("log_tag","position In"+list.get(position));

        }
        return convertView;
    }
  }
}

但结果就像在Image中一样十一点之后它给我看了一，二，二。请帮我 enter image description here

Answer 1

@Override
    public View getView(int position, View convertView, ViewGroup parent) {
         ListHolder holder = null;
        if (convertView == null) {
            convertView = mInflater.inflate(R.layout.cust_list, null);
            holder=new ListHolder();
            holder.tv = (TextView)convertView.findViewById(R.id.txt_title);
            holder.iv = (ImageView)convertView.findViewById(R.id.imageView1);
            Log.v("log_tag","position In"+list.get(position));
            convertView.setTag(holder);
        }
         else
        {
        holder=(ListHolder) convertView.getTag();
        }
        holder.tv.setText(list.get(position));
        return convertView;
    }
 static class ListHolder
{
    TextView tv;

    ImageView iv;
}

始终在持有人中写下其他条件。

Answer 2

将您的getView()更改为：

public View getView(int position, View convertView, ViewGroup parent) {
    if (convertView == null) {
        convertView = mInflater.inflate(R.layout.cust_list, null);
    }
    TextView tv = (TextView)convertView.findViewById(R.id.txt_title);
    ImageView iv = (ImageView)convertView.findViewById(R.id.imageView1);
    tv.setText(list.get(position));
    Log.v("log_tag","position In"+list.get(position));

    return convertView;
}

Answer 3

无法在“正确”的地方添加评论，但Niteesh Mehra建议将LV置于scrollview中是错误的。 LV是一个在垂直滚动列表中显示项目的视图，因此没有必要再次这样做。

至于你的问题 - 你的getView（）实现是错误的。如果convertView不为null，则应该重用视图，但重用意味着您已经烘焙了视图（布局），但是您仍然必须使用此行的内容填充它。所以你应该这样做：

if( convertView == null ) {
 convertView = <inflate view from XML>;
}

然后，您在视图元素中的数据无条件。

Answer 4

我改变了我的getView（）并解决了问题。

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

        convertView = mInflater.inflate(R.layout.cust_list, null);

        TextView tv = (TextView) convertView.findViewById(R.id.txt_title);
        ImageView iv = (ImageView) convertView.findViewById(R.id.imageView1);

        tv.setText(list.get(position));
        tv.setTag(list.get(position));

        if (RadioDemoActivity.this.position==position)
            iv.setImageResource(R.drawable.greenround);

        return convertView;

    }

Answer 5

像这样改变getView方法

if (convertView == null) {
        convertView = mInflater.inflate(R.layout.cust_list, null);
        }
        TextView tv = (TextView)convertView.findViewById(R.id.txt_title);
        ImageView iv = (ImageView)convertView.findViewById(R.id.imageView1);
        tv.setText(list.get(position));
        Log.v("log_tag","position In"+list.get(position));

ListView无法在Android中正确构建

5 个答案: