Question

所以，我想创建一个ListView片段，但所有我得到的都是空白片段。我的猜测是3个布局资源（R.layout.fragment_home）应该是不同的，但我不能理解哪个。

片段代码：

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {


    View rootView = inflater.inflate(R.layout.fragment_home, container, false);
    listView = (ListView) rootView.findViewById(R.layout.fragment_home);
    News n = new News("Pavadinimas", "http://www.google.lt", "Apibudinimas", "2015");
    news.add(n);
    mAdapter = new List(getActivity(), R.layout.fragment_home, news);
    setListAdapter(mAdapter);


    return listView;
}

R.layout.fragment_home：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".List" >


<TextView
    android:id="@+id/textView1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginTop="14dp"
    android:text="Medium Text"
    android:textAppearance="?android:attr/textAppearanceMedium" />

</LinearLayout>

尝试返回rootview后，我得到：E / AndroidRuntime（26302）：引起：java.lang.RuntimeException：内容具有id属性＆＃39; android.R.id.list＆＃39;这不是ListView类也许这里有问题？

frag = new HomeFragment();
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction()
.replace(R.id.frame_container, frag).commit();

mDrawerList.setItemChecked(position, true);
mDrawerList.setSelection(position);
setTitle(navMenuTitles[position]);
mDrawerLayout.closeDrawer(mDrawerList);

数组适配器：

public class List extends ArrayAdapter<News>{

private final Context context;
private final ArrayList<News> news;

public List(Context context, int resource, ArrayList<News> news){
    super(context, resource, news);

    this.context = context;
    this.news=news;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    View rowView = inflater.inflate(R.layout.fragment_home, parent, false);

    TextView textView1 = (TextView) rowView.findViewById(R.id.textView1);
    textView1.setText(news.get(position).desc);
    textView1.setHint(news.get(position).link);

    return rowView;
}
}

新闻类：

public class News
{
public String title;
public String link;
public String desc;
public String date;

public News(String title, String link, String desc, String date)
{
    this.title = title;
    this.link = link;
    this.desc = desc;
    this.date = date;
}
}

Answer 1

我的猜测是3个布局资源（R.layout.fragment_home）应该是不同，但我无法理解。

你是部分正确的。您需要为listView设置一个布局，为片段设置另一个布局。 ListView属于片段布局

为列表视图项目扩充自定义布局。

您需要更改此

listView = (ListView) rootView.findViewById(R.layout.fragment_home);

到

listView = (ListView) rootView.findViewById(R.id.list);

您需要ListView中包含fragment_home.xml个ID列表。

在您的适配器getView中，您需要为自定义布局充气。

编辑：

HomeFragment

public class HomeFragment extends Fragment { // note extends fragment

    ListView listView;
    ArrayList<News> news = new ArrayList<News>();
    List mAdapter;
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {


        View rootView = inflater.inflate(R.layout.fragment_home, container, false);
        listView = (ListView) rootView.findViewById(R.id.listView1);
        News n = new News("Pavadinimas", "http://www.google.lt", "Apibudinimas", "2015");
        news.add(n);
        mAdapter = new List(getActivity(), 0, news);
        listView.setAdapter(mAdapter); // note the change setAdapter

        return rootView;
    }

}

fragment_home.xml

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

    <ListView
        android:id="@+id/listView1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true" >
    </ListView>

</RelativeLayout>

News.java

public class News {
    String name,url,title,year;

    public News(String name, String url, String title, String year) {
        // TODO Auto-generated constructor stub
        this.name= name;
        this.url = url;
        this.title = title;
        this.year=year;
    }

}

List.java

class List extends ArrayAdapter<News>
{
    LayoutInflater mInflater;
    ArrayList<News> news;
    public List(Context context, int resource, ArrayList<News> news) {
        super(context, resource, news);
        mInflater = LayoutInflater.from(context);
        this.news = news;
    }
  public View getView(int pos, View arg1, ViewGroup arg2) {

   ViewHolder holder;
   if(arg1==null)
   {
   arg1=mInflater.inflate(R.layout.list_item, null);
   holder= new ViewHolder();
   holder.tv1 = (TextView) arg1.findViewById(R.id.textView1);
   holder.tv2 = (TextView) arg1.findViewById(R.id.textView2);
   holder.tv3 = (TextView) arg1.findViewById(R.id.textView3);
   arg1.setTag(holder);
   }else
   {
       holder = (ViewHolder) arg1.getTag();
   }
   News n= news.get(pos);
   holder.tv1.setText(n.title);

  return arg1;
}
    static class ViewHolder
    {
        TextView tv1,tv2,tv3;
    }
}

list_item.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" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="31dp"
        android:layout_marginTop="53dp"
        android:text="TextView" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/textView1"
        android:layout_alignBottom="@+id/textView1"
        android:layout_centerHorizontal="true"
        android:text="TextView" />

    <TextView
        android:id="@+id/textView3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/textView2"
        android:layout_alignBottom="@+id/textView2"
        android:layout_alignParentRight="true"
        android:layout_marginRight="21dp"
        android:text="TextView" />

</RelativeLayout>

Answer 2

尝试使用此代码

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".List" >
<ListView
          android:id="@+id/list"
          android:layout_height="wrap_content"
          android:layout_width="match_parent">
  <TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="14dp"
android:text="Medium Text"
android:textAppearance="?android:attr/textAppearanceMedium" />
     </ListView>

</LinearLayout>

Java代码应该是这样的：

     public View onCreateView(LayoutInflater inflater, ViewGroup container,
    Bundle savedInstanceState) {


View rootView = inflater.inflate(R.layout.fragment_home, container, false);
listView = (ListView) rootView.findViewById(R.id.list);
News n = new News("Pavadinimas", "http://www.google.lt", "Apibudinimas", "2015");
news.add(n);
mAdapter = new List(getActivity(), R.layout.fragment_home, news);
listview.setAdapter(mAdapter);


return listView;

}

ListFragment中资源之间的差异

2 个答案: