Java 该活动不替换为片段

我试图调用活动中的片段，但片段布局并不能替换活动，就像在其上构建片段一样，因此它们同时出现。我怎样才能更换它，它不工作了 这是你的电话号码

activity.java

public class AllTasks extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_all_tasks);
        final Button add;
        final EditText text;
        final ListView list;
        add = (Button) findViewById(R.id.addbutton);
        list = (ListView) findViewById(R.id.listView);

        //  public void onClick(View view) {
        ParseObject showlist = new ParseObject("ShowAllTasks");
        showlist.put("TaskNames", showlist);

        showlist.saveInBackground(new SaveCallback() {
            public void done(ParseException e) {
                Toast.makeText(AllTasks.this, "Saved", Toast.LENGTH_LONG).show();
                ParseQuery<ParseObject> query = ParseQuery.getQuery("ShowAllTasks");
                // query.whereEqualTo("playerName", "Dan Stemkoski");
                query.findInBackground(new FindCallback<ParseObject>() {
                    public void done(List<ParseObject> tasklist, ParseException e) {
                        if (e == null) {
                            ArrayList<String> array = new ArrayList<String>();
                            for (ParseObject j : tasklist) {
                                array.add(j.getString("TaskNames"));
                            }
                            ArrayAdapter adapter = new ArrayAdapter(AllTasks.this, android.R.layout.simple_list_item_1, array);
                            list.setAdapter(adapter);
                            // Log.d("score", "Retrieved " + scoreList.size() + " scores");
                        } else {
                            Log.d("score", "Error: " + e.getMessage());
                        }
                    }
                });
            }
        });
        add.setOnClickListener(new View.OnClickListener() {
                                   @Override
                                   public void onClick(View view) {
                                       Fragment frag;
                                       FragmentManager fm = AllTasks.this.getFragmentManager();
                                       FragmentTransaction ft = fm.beginTransaction();
                                       frag = new AddTaskFragment();
                                       //AddTaskFragment llf = new AddTaskFragment();
                                       ft.replace(R.id.alltasks, frag);
                                       ft.addToBackStack(null);
                                       ft.commit();
                                   }
                                   //Intent myIntent = new Intent(AllTasks.this , AddTaskFragment.class);
                                   //startActivity(myIntent);
                               });
    }
    //  });
}

片段.xml

<RelativeLayout 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:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context="info.androidhive.slidingmenu.AllTasks"
android:id="@+id/alltasks">

<TextView
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceMedium"
    android:text="YourTasks :"
    android:id="@+id/textViewyourtasks"
    android:layout_alignParentStart="true" />

<ListView
    android:layout_width="wrap_content"
    android:layout_height="386dp"
    android:id="@+id/listView"
    android:clickable="true"
    android:layout_alignParentStart="true"
    android:layout_below="@+id/deletebutton"
    android:layout_alignEnd="@+id/deletebutton"
    android:layout_gravity="center_horizontal|bottom" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Add"
    android:id="@+id/addbutton"
    android:layout_alignParentTop="true"
    android:layout_toStartOf="@+id/deletebutton"
    android:layout_gravity="right|top" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Delete"
    android:id="@+id/deletebutton"
    android:layout_alignParentEnd="true"
    android:layout_alignTop="@+id/textViewyourtasks"
    android:layout_gravity="center_horizontal|top" />

public class AddTaskFragment extends Fragment {
    public AddTaskFragment() {}

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

        View rootView = inflater.inflate(R.layout.fragment_add_task, container, false);

        Button add;
        final EditText tasktext;
        final EditText taskdate;
        final EditText tasknote;
        taskdate = (EditText) rootView.findViewById(R.id.editTextDate);
        tasktext = (EditText) rootView.findViewById(R.id.editTexttaskname);
        tasknote = (EditText) rootView.findViewById(R.id.editTextnote);

        add = (Button) rootView.findViewById(R.id.addbutton);

        add.setOnClickListener(new View.OnClickListener() {
                                   @Override
                                   public void onClick(View view) {
                                       ParseObject showlist = new ParseObject("ShowAllTasks");
                                       showlist.put("TaskNames", tasktext.getText().toString());
                                       showlist.put("Date", taskdate.getText().toString());
                                       showlist.put("Note", tasknote.getText().toString());
                                       showlist.saveInBackground(new SaveCallback() {
                                           @Override
                                           public void done(ParseException e) {
                                               taskdate.setText("");
                                               tasknote.setText("");
                                               tasktext.setText("");
                                               Toast.makeText(getActivity(), "Saved", Toast.LENGTH_LONG).show();
                                               Intent myIntent = new Intent(getActivity(), AllTasks.class);
                                               getActivity().startActivity(myIntent);

                                           }
                                       });
                                   }
                               }
        );
        return rootView;
    }
}

<FrameLayout 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"
tools:context="info.androidhive.slidingmenu.AddTaskFragment"
android:id="@+id/fo">

<!-- TODO: Update blank fragment layout -->
<LinearLayout
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:longClickable="false">

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/editTextDate"
        android:hint="Enter task date  "
        android:layout_gravity="center_vertical"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true" />

    <EditText
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:id="@+id/editTextnote"
        android:hint="Enter any note  "
        android:layout_gravity="left"
        android:layout_alignBottom="@+id/editTexttaskname"
        android:layout_alignEnd="@+id/editTextDate" />

    <EditText
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:id="@+id/editTexttaskname"
        android:hint="Enter task name here  "
        android:layout_below="@+id/editTextDate"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="0dp" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/AddButton"
        android:id="@+id/addbutton"
        android:layout_gravity="center_horizontal" />
</LinearLayout>

---

谁能帮我找出我的代码有什么问题吗？

我希望我正确理解了你的目的。

---

如果要同时显示活动的当前内容和片段，则应在根相对论窗口内的活动布局文件中添加另一个布局，并从代码中将片段添加到该布局。

片段可以是活动的一部分，而不是替换活动。您的理解有误或您的解释拼写有误，如回答“否”，它已显示在对方的屏幕上，我希望当我单击按钮时，活动被替换为片段。您必须将当前内容包装成片段，将此片段添加到活动中，而不是添加单独的视图，并在单击按钮时将此片段替换为另一个片段。