片段列表视图中的自定义适配器

Question

我正在尝试将自定义适配器添加到片段中的列表视图中。它运行正常，但它没有显示碎片中的任何内容。我尝试了很多方法，但我无法让它发挥作用。任何帮助都会很棒。提前致谢。这是我的代码： 的 fragment.xml之

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">


<ListView
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:id="@+id/UniFeeList"
    android:layout_centerHorizontal="true"
    android:clickable="true"
    >

</ListView>


<android.support.design.widget.FloatingActionButton
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@android:drawable/ic_input_add"
    android:id="@+id/addQuestion"
    android:layout_alignParentBottom="true"
    android:layout_alignParentRight="true"
    android:layout_margin="10dip"
    />


</RelativeLayout>

Fragment.Java

public class UniFeedFragment extends Fragment {
    ListView uniFeedListview;
    FloatingActionButton askQuestion;
    String stdEmail, UniEmail;
    TextView tv;
    Post post;
    String date,time;
    ListView UniFeedList;


    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        ViewGroup view =  (ViewGroup) inflater.inflate(R.layout.unifeedfragment, container, false);



        //Getting Time
        DateFormat df = new SimpleDateFormat("HH:mm");
        time = df.format(Calendar.getInstance().getTime());

        //Getting Date
        DateFormat dateFormatter = new SimpleDateFormat("yyyy-MM-dd");
        Date today = new Date();
        date = dateFormatter.format(today);

        //Getting data from news feed search bar
        UniFeed uniFeed = (UniFeed) getActivity();
        stdEmail = uniFeed.stdEmail;
        UniEmail = uniFeed.uni.getEmail();

        //Setting Listview
        UniFeedList = (ListView) view.findViewById(R.id.UniFeeList);
        final ArrayList<Post> postArray = new ArrayList<Post>();
        PostListAdapter PostList = new PostListAdapter(this.getActivity(), R.layout.activity_uni_feed ,postArray);
        UniFeedList.setAdapter(PostList);


        return view;
    }

PostListAdapter.java

public class PostListAdapter extends BaseAdapter {
Context context = null;
ArrayList<Post> postData = new ArrayList<>();
LayoutInflater inflater;

public PostListAdapter(Context context, int activity_uni_feed, ArrayList<Post> postData){
    this.context = context;
    this.postData = postData;
}

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

@Override
public Object getItem(int position) {
    return null;
}

@Override
public long getItemId(int position) {
    return 0;
}

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

        inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        convertView= inflater.inflate(R.layout.unifeedpost, parent, false);

    return convertView;
} }

unifeedPost.xml

<?xml version="1.0" encoding="utf-8"?>

<ImageView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/stdProfileImage"
    android:layout_alignParentTop="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:src="@mipmap/ic_launcher"
    />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:text="Name"
    android:id="@+id/stdName"
    android:layout_alignTop="@id/stdProfileImage"
    android:layout_toRightOf="@+id/stdProfileImage"
     />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceMedium"
    android:text="Date and Time"
    android:id="@+id/time"
    android:layout_below="@+id/stdName"
    android:layout_toRightOf="@+id/stdProfileImage"
    android:layout_toEndOf="@+id/stdProfileImage" />

<TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/postContent"
    android:layout_below="@id/time"
    android:text="Test Post"
    android:layout_marginTop="10dip"
    android:layout_toRightOf="@id/stdProfileImage"
    />
<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@id/postContent"
    android:layout_toRightOf="@id/stdProfileImage"
    android:layout_marginTop="10dip"
    >
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Like"
        android:layout_weight="0.5"
        />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Comment"
        android:layout_weight="0.5"
        />

</LinearLayout>