Question

我是android app dev的新手，我正在尝试创建一个由TextView和ListView组成的ListFragment。我想尝试使用自定义类中的数据填充ListView，从而创建自定义ArrayAdapter。我的应用程序运行，但没有在列表中显示任何内容，我无法弄清楚为什么不。我已经记录了数据并且它存在于持有者中并且文本似乎已经设置但是出了点问题。

row_layout.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="?android:attr/listPreferredItemHeight"
android:padding="6dip" >

 <LinearLayout
    android:orientation="vertical"

    android:layout_width="0dip"
    android:layout_weight="1"
    android:layout_height="fill_parent">

    <TextView
        android:id="@+id/TextViewStation"
        android:layout_width="fill_parent"
        android:layout_height="0dip"
        android:layout_weight="1"

        android:gravity="center_vertical"
        android:text="My Application" />

    <TextView
        android:id="@+id/TextViewType"  
        android:layout_width="fill_parent"
        android:layout_height="0dip"
        android:layout_weight="1" 

        android:singleLine="true"
        android:ellipsize="marquee"
        android:text="Simple application that shows how to use RelativeLayout" />

</LinearLayout>

</RelativeLayout>

list_layout.xml

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

<TextView
    android:id="@+id/android:empty"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:text="No items to display." />

<ListView
    android:id="@+id/android:list"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

</LinearLayout>

SimpleArrayAdapter.java

 public class SimpleArrayAdapter extends ArrayAdapter<Warning> {
private final Context context;
private final List<Warning> objects;

public SimpleArrayAdapter(Context context, int resource,
        List<Warning> objects) {
    super(context, resource);
    this.context = context;
    this.objects = objects;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View row = convertView;
    ViewHolder holder = new ViewHolder();

    if (row == null) {
        LayoutInflater inflater = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        row = inflater.inflate(R.layout.row_layout, parent, false);
        holder.v1 = (TextView) row.findViewById(R.id.TextViewStation);
        holder.v2 = (TextView) row.findViewById(R.id.TextViewType);
        row.setTag(holder);
    } else {
        holder = (ViewHolder) row.getTag();
    }
    final Warning warning = objects.get(position);
    if (warning != null) {
        holder.v1.setText(warning.getStation());
        holder.v2.setText(warning.getType());
        // Log.d("Adapter", "holder.v1.getText(): " + holder.v1.getText());
    }
    return row;
}

public static class ViewHolder {
    TextView v1; // view1
    TextView v2; // view2
}

@Override
public int getCount() {
    return objects.size();
}

@Override
public Warning getItem(int position) {
    // TODO Auto-generated method stub
    return objects.get(position);
}
}

List_View.java - ListFragment

    public class List_View extends ListFragment {
List<Warning> items = new ArrayList<Warning>();

    Gson gson = new Gson();
private SimpleArrayAdapter adapter;
private ListView mListView;

// @Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // ---- Get data!
    JsonElement je = new JsonParser().parse(result);
    JsonObject jo = je.getAsJsonObject();
    JsonArray ja = jo.getAsJsonArray("warnings");

    for (int i = 0; i < ja.size(); i++) {
        Warning war = new Warning();
        war = gson.fromJson(ja.get(i).getAsJsonObject(), Warning.class);
        items.add(war);
    }
    // ----
}

// @Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    View rootView = inflater
            .inflate(R.layout.list_layout, container, false);
    // RESTManager manager = new RESTManager();
    return rootView;
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    Log.d("Adapter", "items.size(): "+ items.size());
    adapter = new SimpleArrayAdapter(getActivity(), R.layout.row_layout,
            items);
    setListAdapter(adapter);
}
}

在SimpleArrayAdapter中，我记录来自holder.v1.getText（）的结果会返回正确的值，但仍未在应用程序的ListView中显示任何内容。

Answer 1

试试这个：

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


   TextView station, type ;

   if (row == null) {
       LayoutInflater inflater = (LayoutInflater) context
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
       row = inflater.inflate(R.layout.row_layout, parent, false);
       station = (TextView) row.findViewById(R.id.TextViewStation);
       type  = (TextView) row.findViewById(R.id.TextViewType);

   }

   Warning warning = objects.get(position);
   if (warning != null) {
       station.setText(warning.getStation());
       type.setText(warning.getType());
       // Log.d("Adapter", "holder.v1.getText(): " + holder.v1.getText());
   }
   return row;
}

Answer 2

我发现了问题。愚蠢的由于某种原因我有android：layout_width =“0dip”为textviews ........改为android：layout_width =“fill_parent”和繁荣，有我的数据！

通过自定义ArrayAdapter填充ListFragment中的列表 - 我的数据未显示但存在于适配器中

2 个答案: