布局代码：
菜单文件：
完整代码：
public class MainActivity extends Activity { private TextView tvMsg; private float fontSize = 15.0f; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); tvMsg = (TextView) findViewById(R.id.tv); tvMsg.setTextSize(fontSize); } public void showPopup(View v){ //锚点 PopupMenu popup = new PopupMenu(this,v); getMenuInflater().inflate(R.menu.main, popup.getMenu()); //显示菜单 popup.show(); //处理菜单项的点击事件 popup.setOnMenuItemClickListener(new OnMenuItemClickListener() { @Override public boolean onMenuItemClick(MenuItem item) { switch (item.getItemId()) { case R.id.action_add: fontSize+=5; break; case R.id.action_sub: fontSize-=5; break; } tvMsg.setTextSize(fontSize); return false; } }); }}
