Question

我已经实施了一个教程，我有一个问题要适应我的方式。

带有de ListView的main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" 
    android:layout_width="fill_parent" android:layout_height="fill_parent">
    <ListView android:id="@+id/listView1" android:layout_height="match_parent" android:layout_width="match_parent" />
</LinearLayout>

rowview.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal" android:layout_width="match_parent"
    android:layout_height="wrap_content" android:weightSum="1">
    <TextView android:layout_width="wrap_content"
        android:layout_height="match_parent" android:id="@+id/text"
        android:layout_weight="0.5" android:textSize="25sp" />
    <Spinner android:layout_width="0dp" android:layout_height="wrap_content"
        android:id="@+id/spin" android:prompt="@string/choice_prompt"
        android:layout_weight="0.5" />
</LinearLayout>

strings.xml文件。

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="hello">Hello World, ListViewTestActivity!</string>
    <string name="app_name">ListViewTest</string>
    <string name="choice_prompt">Select a choice</string>
    <string-array name="choices">
        <item>Alpha</item>
        <item>Bravo</item>
        <item>Charlie</item>
    </string-array>
</resources>

ListViewActivity类：

public class ListViewTestActivity extends Activity {

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

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

        DataHolder data = new DataHolder(this);
        DataHolder data1 = new DataHolder(this);
        DataHolder data2 = new DataHolder(this);
        DataHolder data3 = new DataHolder(this);
        DataHolder data4 = new DataHolder(this);

        DataAdapter d = new DataAdapter(this, R.layout.rowview, new DataHolder[] { data, data1, data2, data3, data4 });

        listView.setAdapter(d);
    }
}

DataHolder类：

public class DataHolder {

    private int selected;
    private ArrayAdapter<CharSequence> adapter;

    public DataHolder(Context parent) {
        adapter = ArrayAdapter.createFromResource(parent, R.array.choices, android.R.layout.simple_spinner_item);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    }

    public ArrayAdapter<CharSequence> getAdapter() {
        return adapter;
    }

    public String getText() {
        return (String) adapter.getItem(selected);
    }

    public int getSelected() {
        return selected;
    }

    public void setSelected(int selected) {
        this.selected = selected;
    }

}

所有DataHolder类：

public class DataAdapter extends ArrayAdapter<DataHolder> {

    private Activity myContext;

    public DataAdapter(Activity context, int textViewResourceId, DataHolder[] objects) {
        super(context, textViewResourceId, objects);
        myContext = context;
    }

    // We keep this ViewHolder object to save time. It's quicker than findViewById() when repainting.
    static class ViewHolder {
        protected DataHolder data;
        protected TextView text;
        protected Spinner spin;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View view = null;

        // Check to see if this row has already been painted once.
        if (convertView == null) {

            // If it hasn't, set up everything:
            LayoutInflater inflator = myContext.getLayoutInflater();
            view = inflator.inflate(R.layout.rowview, null);

            // Make a new ViewHolder for this row, and modify its data and spinner:
            final ViewHolder viewHolder = new ViewHolder();
            viewHolder.text = (TextView) view.findViewById(R.id.text);
            viewHolder.data = new DataHolder(myContext);
            viewHolder.spin = (Spinner) view.findViewById(R.id.spin);
            viewHolder.spin.setAdapter(viewHolder.data.getAdapter());

            // Used to handle events when the user changes the Spinner selection:
            viewHolder.spin.setOnItemSelectedListener(new OnItemSelectedListener() {

                @Override
                public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
                    viewHolder.data.setSelected(arg2);
                    viewHolder.text.setText(viewHolder.data.getText());
                }

                @Override
                public void onNothingSelected(AdapterView<?> arg0) {
                }

            });

            // Update the TextView to reflect what's in the Spinner
            viewHolder.text.setText(viewHolder.data.getText());

            view.setTag(viewHolder);

            Log.d("DBGINF", viewHolder.text.getText() + "");
        } else {
            view = convertView;
        }

        // This is what gets called every time the ListView refreshes
        ViewHolder holder = (ViewHolder) view.getTag();
        holder.text.setText(getItem(position).getText());
        holder.spin.setSelection(getItem(position).getSelected());

        return view;
    }
}

要查看此代码的结果，请参阅 - ＆gt; Android Listview with spinner and a checkbox

这段代码有效，我有一个带有微调器的listView用于每个项目，但我如何用我自己的字符串填充微调器？我试着在DataHolder类中填充它们但它失败了。（我有一个字符串列表）。

提前感谢。

Answer 1

所有工作都在DataAdapter的ADAPTER中完成。

单元格在GetView方法中构建，每个单元格都被回收：如果convertView为null，则创建一个要使用的新单元格，否则使用convertView。

我假设您必须更改DataHolder中的一些代码

public DataHolder(Context parent) {
    adapter = ArrayAdapter.createFromResource(parent, R.array.choices, android.R.layout.simple_spinner_item);
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
}

现在你必须明白，静态提供了一系列选择：

R.array.choices

一种解决方案是在构建viewHolders时传递数据：

 viewHolder.data = new DataHolder(myContext);

应该是这样的：

 viewHolder.data = new DataHolder(myContext, myDataArray);

然后在你的班级中用更类似的东西改变适配器的实例..

public DataHolder(Context parent, ArrayList<String> dataArray) {
    adapter = new ArrayAdapter<String>(myContext, yourTextViewId, dataArray);
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
}

希望它有所帮助祝你好运

如何填写我自己的字符串

1 个答案: