正常情况下,它不会自动刷新。您正在向“lista”中添加一个项目,但适配器保留其自己的列表副本,因此您需要重新设置适配器中的列表,然后调用notifyDataChanged或将新项目添加到适配器。
无论如何,我看到了几件奇怪的事情,我认为您可以使用数组适配器简化所有内容,您不需要实现add等功能。我编写了一些代码来简化您的代码:
public class WeatherAppActivity extends ListActivity {
Button buton;
ItemsAdapter lista;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
List<String> initialList = new ArrayList<String>();
initialList.add("Bucuresti");
initialList.add("Sibiu");
lista=new ItemsAdapter(this, initialList);
buton=(Button)findViewById(R.id.button1);
buton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
lista.add(""+System.currentTimeMillis());
lista.notifyDataSetChanged();
}
});
setListAdapter(lista);
}
class ItemsAdapter extends ArrayAdapter<String> {
public ItemsAdapter(Context context, List<String> list) {
super(context, R.layout.lista, list);
}
@Override
public View getView(final int position, View row, final ViewGroup parent) {
final String item = getItem(position);
ItemWrapper wrapper = null;
if (row == null) {
row = getLayoutInflater().inflate(R.layout.lista, parent, false);
wrapper = new ItemWrapper(row);
row.setTag(wrapper);
} else {
wrapper = (ItemWrapper) row.getTag();
}
wrapper.refreshData(item);
return row;
}
class ItemWrapper {
TextView text;
public ItemWrapper(View row) {
text = (TextView) row.findViewById(R.id.elementLista);
}
public void refreshData(String item) {
text.setText(item);
}
}
}
}
这些是我使用过的 XML 文件:
main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="63dp"
android:text="Button" />
<ListView
android:id="@id/android:list"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true" >
</ListView>
</RelativeLayout>
lista.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="@+id/elementLista"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Medium Text"
android:textAppearance="?android:attr/textAppearanceMedium" />
</LinearLayout>
这是使用BaseAdapter的适配器版本:
class ItemsBaseAdapter extends BaseAdapter {
private List<String> items;
private Context mContext;
public ItemsBaseAdapter(Context context, List<String> list) {
items = list;
mContext = context;
}
public void addItem(String str) {
items.add(str);
}
@Override
public View getView(final int position, View row, final ViewGroup parent) {
final String item = (String) getItem(position);
ItemWrapper wrapper = null;
if (row == null) {
row = getLayoutInflater().inflate(R.layout.lista, parent, false);
wrapper = new ItemWrapper(row);
row.setTag(wrapper);
} else {
wrapper = (ItemWrapper) row.getTag();
}
wrapper.refreshData(item);
return row;
}
class ItemWrapper {
TextView text;
public ItemWrapper(View row) {
text = (TextView) row.findViewById(R.id.elementLista);
}
public void refreshData(String item) {
text.setText(item);
}
}
@Override
public int getCount() {
return items.size();
}
@Override
public Object getItem(int position) {
return items.get(position);
}
@Override
public long getItemId(int position) {
return 0;
}
}
这是包含左侧图像视图的列表项的版本:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal" >
<ImageView
android:layout_height="wrap_content"
android:src="@android:drawable/btn_star_big_on"
android:scaleType="fitCenter"
android:layout_width="wrap_content"
/>
<TextView
android:id="@+id/elementLista"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Medium Text"
android:textAppearance="?android:attr/textAppearanceMedium"
/>
</LinearLayout>