android - 如何在 fragment 中膨胀另一个 View ？

Question

我的应用有一个带有两个选项卡的选项卡式 Activity 。我希望另一个 View abcd.xml 在选项卡的 fragment 中膨胀。我试过这样做，但没有用。

这是扩展 fragment 的代码。收入 fragment .java

public class IncomeFrag extends Fragment{
    private static final String TAG = "Income Frag";


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

    private void populate() {

        SQLiteDatabase mydatabase = getActivity().openOrCreateDatabase("tracker",MODE_PRIVATE,null);

        Intent intent = getActivity().getIntent();
        int user_id = Integer.parseInt(intent.getStringExtra("user_id"));

        LinearLayout linearLayout = (LinearLayout) getActivity().findViewById(R.id.inc_frag_tab);

        LayoutInflater vi = (LayoutInflater) getActivity().getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        try {
            Cursor rs = mydatabase.rawQuery("select * from transactions where user_id = " + user_id + ";", null);

            if (rs.moveToLast()) {
                do {
                    View pastItem = vi.inflate(R.layout.abcd, null);
                    int amount = rs.getInt(2);
                    String cat = rs.getString(3);
                    String description = rs.getString(4);
                    String type = rs.getString(5);
                    String date = rs.getString(6);

                    if (type.equalsIgnoreCase("income")) {
                        TextView amt_tv = (TextView) pastItem.findViewById(R.id.amount_inflator);
                        amt_tv.setText(Integer.toString(amount));
                        amt_tv.setTextColor(getResources().getColor(R.color.green));
                        TextView cat_tv = (TextView) pastItem.findViewById(R.id.category_inflator);
                        cat_tv.setText(cat);
                        TextView desc_tv = (TextView) pastItem.findViewById(R.id.description_inflator);
                        desc_tv.setText(description);
                        TextView date_tv = (TextView) pastItem.findViewById(R.id.date_inflator);
                        date_tv.setText(date);

                        linearLayout.addView(pastItem);
                    }
                } while (rs.moveToPrevious());
            }
            rs.close();
        }
        catch (Exception e) {
            // Nothing
        }
    }
}

这是我要膨胀的 View 的 xml 文件 abcd.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:padding="7sp">

    <TextView
        android:id="@+id/amount_inflator"
        android:text="@string/username"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="25sp"
        android:textColor="#FF0000"
        android:paddingBottom="3sp"/>

    <TextView
        android:id="@+id/category_inflator"
        android:text="abcd"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="20sp"
        android:paddingBottom="2sp"/>
    <TextView
        android:id="@+id/description_inflator"
        android:text="@string/app_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/date_inflator"
        android:text="@string/app_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <android.support.v4.widget.Space
        android:layout_width="match_parent"
        android:layout_height="15sp" />

</LinearLayout>

我想让它在这里膨胀

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

<ScrollView
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <LinearLayout
        android:id="@+id/inc_frag_tab"
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

    </LinearLayout>

</ScrollView>

</LinearLayout>

Answer 1

在处理 fragment 时，您无法通过 onCreateView() 方法访问 LinearLayout 或 TextView 等 View 。尝试将 populate() 方法放在 onViewCreated() 中，而不是像这样，看看它是否有效。

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

@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    populate();