EditText中未显示Android默认的剪切/复制/粘贴

<EditText
    android:id="@+id/editText"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textIsSelectable="true" />

EditText editText = findViewById(R.id.editText);
registerForContextMenu(editText);

@Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
    super.onCreateContextMenu(menu, v, menuInfo);
    getMenuInflater().inflate(R.menu.context_menu, menu);
}

<menu xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:id="@+id/cut"
        android:title="剪切" />
    <item
        android:id="@+id/copy"
        android:title="复制" />
    <item
        android:id="@+id/paste"
        android:title="粘贴" />
</menu>

@Override
public boolean onContextItemSelected(MenuItem item) {
    EditText editText = findViewById(R.id.editText);
    switch (item.getItemId()) {
        case R.id.cut:
            editText.cut();
            return true;
        case R.id.copy:
            editText.copy();
            return true;
        case R.id.paste:
            editText.paste();
            return true;
        default:
            return super.onContextItemSelected(item);
    }
}

EditText editText = findViewById(R.id.editText);
editText.setCustomSelectionActionModeCallback(new ActionMode.Callback() {
    @Override
    public boolean onCreateActionMode(ActionMode mode, Menu menu) {
        getMenuInflater().inflate(R.menu.custom_selection_menu, menu);
        return true;
    }

    @Override
    public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
        return false;
    }

    @Override
    public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
        EditText editText = findViewById(R.id.editText);
        int start = editText.getSelectionStart();
        int end = editText.getSelectionEnd();
        CharSequence selectedText = editText.getText().subSequence(start, end);
        switch (item.getItemId()) {
            case R.id.cut:
                editText.getText().replace(start, end, "");
                mode.finish();
                return true;
            case R.id.copy:
                ClipboardManager clipboard = (ClipboardManager) getSystemService(Context.CLIPBOARD_SERVICE);
                ClipData clip = ClipData.newPlainText("text", selectedText);
                clipboard.setPrimaryClip(clip);
                mode.finish();
                return true;
            case R.id.paste:
                editText.getText().replace(start, end, clipboard.getPrimaryClip().getItemAt(0).getText());
                mode.finish();
                return true;
            default:
                return false;
        }
    }

    @Override
    public void onDestroyActionMode(ActionMode mode) {
    }
});

<menu xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:id="@+id/cut"
        android:title="剪切" />
    <item
        android:id="@+id/copy"
        android:title="复制" />
    <item
        android:id="@+id/paste"
        android:title="粘贴" />
</menu>