PopupMenu使用：

插入头文件：

import java.lang.reflect.Field;
import com.android.internal.view.menu.MenuPopupHelper;
import android.view.Menu;
import android.view.MenuInflater;
import android.widget.ImageView;
import android.widget.PopupMenu;
import android.widget.PopupMenu.OnDismissListener;
import android.widget.PopupMenu.OnMenuItemClickListener;
import android.view.KeyEvent;

代码如下：

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.fm_action_bar_favorite, menu);
        mFlowMenuItem = menu.findItem(R.id.fm_menu_favorite);
        return true;
    }
    public void showPopupMenu() {
        mPopupMenu = new PopupMenu(mContext, findViewById(R.id.fm_menu_favorite));
        Menu menu = mPopupMenu.getMenu();
        mPopupMenu.getMenuInflater().inflate(R.menu.fm_menu_favorite, menu);
        mPopupMenu.setOnMenuItemClickListener(new OnMenuItemClickListener() {
            @Override
            public boolean onMenuItemClick(MenuItem item) {
                switch (item.getItemId()) {
                    case R.id.fm_station_add:
                        showAddNewStationDialog();
                        break;

                    case R.id.fm_remove_all:
                        showRemoveAllStationDialog();
                        break;

                    case R.id.fm_return:
                        finish();
                        break;

                    default:
                        break;
                }
                return false;
            }
        });
        mPopupMenu.setOnDismissListener(new OnDismissListener() {
            @Override
            public void onDismiss(PopupMenu menu) {
                mFlowMenuItem.setEnabled(true);
                invalidateOptionsMenu();
            }
        });
        try {
            Field field = mPopupMenu.getClass().getDeclaredField("mPopup");
            field.setAccessible(true);
            MenuPopupHelper mHelper = (MenuPopupHelper) field.get(mPopupMenu);
            mHelper.setForceShowIcon(true);
        } catch (IllegalAccessException | NoSuchFieldException e) {
            e.printStackTrace();
        }
        mPopupMenu.show();
    }
    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_MENU){
            mFlowMenuItem.setEnabled(false);
            showPopupMenu();
            return true;
        }
        return super.onKeyDown(keyCode, event);
    }

@Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if (item.getItemId() == android.R.id.home) {
            super.onBackPressed();
            return true;
        }

        if (item.getItemId() == R.id.fm_menu_favorite) {
            item.setEnabled(false);
            showPopupMenu();

        }

        return super.onOptionsItemSelected(item);
    }