android - fragment 出现在 Activity 上

Question

我想在单击 ListView 中的项目时显示一个 fragment 。 ListView 在主要 Activity 中。问题是 fragment 出现在 Activity ListView 上。你知道问题出在哪里吗？

主要 Activity :

public class MainActivity extends AppCompatActivity {

    ArrayList<String> test = new ArrayList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

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

        test.add("item 1");
        test.add("item 2");

        ArrayAdapter arrayAdapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, test);
        listView.setAdapter(arrayAdapter);

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                EditorFragment editorFragment = new EditorFragment();

                getSupportFragmentManager().beginTransaction()
                        .add(R.id.fragment_container, editorFragment).commit();
            }
        });
    }
**activity main xml**

    <?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/fragment_container"
        android:layout_width="0dp"
        android:layout_height="0dp"
        tools:layout_editor_absoluteY="8dp"
        tools:layout_editor_absoluteX="8dp" />

    <ListView
        android:id="@+id/listView"
        android:layout_width="368dp"
        android:layout_height="495dp"
        tools:layout_editor_absoluteX="8dp"
        tools:layout_editor_absoluteY="8dp" />
</android.support.constraint.ConstraintLayout>

fragment 编辑器xml

<EditText xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/editor"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="top|left"
    android:inputType="text"
    android:hint="@string/hint"/>

EditorFragment

public class EditorFragment extends Fragment {

    private EditText editor=null;


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

        editor=(EditText) (result.findViewById(R.id.editor));

        return result;

    }
}

我在 fragment 中使用了 removeAllViews 方法，但是当点击项目时它不起作用， fragment 没有出现。

public class EditorFragment extends Fragment {

        private EditText editor=null;


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

            if(container != null)
            {
                container.removeAllViews();
            }

            editor=(EditText) (result.findViewById(R.id.editor));

            return result;

        }
    }

Answer 1

我不确定是否能解决问题，但也许您可以尝试在不使用任何 fragment 时将容器可见性设置为不可见，并在需要时显示它。