片段未在活动中显示

Question

目前，在运行我的应用程序时，转到此活动不会显示我的片段。我是否错误地添加了片段，因此片段中没有显示任何内容？或者片段onCreateView方法中的动态行为是否有问题？

我的活动代码

public class AskQuestionActivity extends FragmentActivity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.ask_question);
    }
}

我的活动XML

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

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">

    <TextView android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:hint="@string/header_text"/>
    <fragment android:name="com.mypackage.AskQuestionFragment"
              android:id="@+id/question_fragment"
              android:layout_weight="1"
              android:layout_width="0dp"
              android:layout_height="match_parent" />
</LinearLayout>

My Fragment Code

public class AskQuestionFragment extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        String questionText = "What is your favorite color?";
        List<String> answers = Arrays.asList("Red", "Blue", "Yellow");

        LinearLayout layout = (LinearLayout)inflater.inflate(R.layout.question, container);
        Resources res = getResources();

        int id = res.getIdentifier("question_text", "id", layout.getContext().getPackageName());
        TextView questionTextView = (TextView)layout.findViewById(id);
        questionTextView.setText(questionText);

        id = res.getIdentifier("question_answers", "id", layout.getContext().getPackageName());
        RadioGroup radioGroup = (RadioGroup)layout.findViewById(id);

        Collections.reverse(answers);
        for (String s : answers) {
            RadioButton button = new RadioButton(layout.getContext());
            button.setText(s);
            radioGroup.addView(button, 0);
        }

        return layout;
    }
}

My Fragment XML

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

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:id="@+id/question_container"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:orientation="vertical" >
    <TextView android:layout_width="fill_parent"
              android:layout_height="fill_parent"
              android:id="@+id/question_text"/>
    <RadioGroup android:layout_width="fill_parent"
                android:layout_height="fill_parent"
                android:id="@+id/question_answers"></RadioGroup>
    <Button
            android:id="@+id/submit_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/submit_button_text"
            />

</LinearLayout>

Answer 1

尝试在xml中放置framelayout而不是fragment。并在您的活动的onCreate中创建要显示的片段实例并将其添加到片段容器中

公共类AskQuestionActivity扩展了FragmentActivity {

 @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.ask_question);

         AskQuestionFragment fragment =  new  AskQuestionFragment();

        getSupportFragmentManager().beginTransaction()
                .add(R.id.id_of_your_container, fragment).commit();



    }
}

Answer 2

执行此操作时可能出现问题：

LinearLayout layout = (LinearLayout)inflater.inflate(R.layout.question, container);

考虑用以下之一替换该行：

LinearLayout layout = (LinearLayout)inflater.inflate(R.layout.question, null);

或

LinearLayout layout = (LinearLayout)inflater.inflate(R.layout.question, container, false);

Answer 3

将您的布局从线性更改为framelayout，并将您的片段附加到活动中。

 getSupportFragmentManager().beginTransaction()
            .add(R.id.your_fragment_container, fragment).commit();