ListView与ArrayAdapter和ViewHolder将图标添加到错误的项目

Question

我有一个ListView使用动态的动态ArrayAdapter.当从微调器中选择一个名称时,该名称以及一个显示它们是男性还是女性的图标会被添加到ListView.

一切都很好(名称正确地添加到列表中,与图标一起).但是显示性别的图标被添加到了错误的项目中ListView.名称将添加到列表的底部,但图标将放置在列表顶部的名称处.我不知道这是否是我使用的方式,ViewHolder但Android网站上没有文档.

// Listview inflater
inflater = (LayoutInflater) (this).getSystemService(LAYOUT_INFLATER_SERVICE);

// List Array.
mAdapter = new ArrayAdapter<String>(this, R.layout.player_simple_list, 
                                                 R.id.label, mStrings) {

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

        Log.i("ANDY","View getView Called");
        // A ViewHolder keeps references to children views to 
        // avoid unneccessary calls to findViewById() on each row.
        ViewHolder holder;

        if (null == convertView) {
            Log.i("ANDY","Position not previously used, so inflating");
            convertView = inflater.inflate(R.layout.player_simple_list, null);
            // Creates a ViewHolder and store references to the
            // two children views we want to bind data to.
            holder = new ViewHolder();
            holder.text = (TextView) convertView.findViewById(R.id.label);
            holder.icon = (ImageView) convertView.findViewById(R.id.icon);
            if (sexmale == true) {
                holder.icon.setImageBitmap(maleicon);
            }
            else {
                holder.icon.setImageBitmap(femaleicon);
            }
            convertView.setTag(holder);
        } else {
            // Get the ViewHolder back to get fast access to the TextView
            // and the ImageView.
            holder = (ViewHolder) convertView.getTag();

        }
        // Bind the data efficiently with the holder.
        holder.text.setText(getItem(position));
        // Change icon depending is the sexmale variable is true or false.
        Log.i("ANDY","getCount = "+mAdapter.getCount());
        return convertView;
    }
};
setListAdapter(mAdapter);

Answer 1

更新： ViewHolder仅用于保存对项目布局内组件视图的引用。这有助于避免调用findViewById在具有多个组件的复杂项目布局中渲染每个组件的开销（如本例中的TextView, 和ImageView）。

我通过使用例程（称为getSex）来检索性别数据并设置所有视图数据（包括if-else块外的图标）来修复此问题。

现在的工作代码如下所示：

if (null == convertView) {
    Log.i("ANDY","Position not previously used, so inflating");
    convertView = inflater.inflate(R.layout.player_simple_list, null);

    // Creates a ViewHolder and store references to the two children views
    // we want to bind data to.
    holder = new ViewHolder();
    holder.text = (TextView) convertView.findViewById(R.id.label);
    holder.icon = (ImageView) convertView.findViewById(R.id.icon);
    convertView.setTag(holder);
} else {
    // Get the ViewHolder back to get fast access to the TextView
    // and the ImageView.
    holder = (ViewHolder) convertView.getTag();
}

// Bind the data efficiently with the holder.
holder.text.setText(getItem(position));
// Change icon depending is the sexmale variable is true or false.
if (getSex (getItem(position)) == true)  {
    holder.icon.setImageBitmap(maleicon);
}
else {
    holder.icon.setImageBitmap(femaleicon);
}
return convertView;