Java Android-我的菜单不显示。我什么都试过了

我做了一个全新的项目，但是当我运行程序时，我的菜单没有出现

这是我的XML代码

<?xml version="1.0" encoding="utf-8"?>
<menu 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"
    tools:context=".WeatherActivity">
 <item
    android:id="@+id/action_settings"
    android:enabled="true"
    android:orderInCategory="100"
    android:title="@string/Град"

    android:visible="true"
    app:showAsAction="always" />

</menu>

---

我不能做菜单。我试过：

public boolean onCreateOptionsMenu(Menu menu)
{
    MenuInflater menuInflater = getMenuInflater();
    menuInflater.inflate(R.menu.main5, menu);
    return true;

    /*getMenuInflater().inflate(R.menu.main5,menu);
    return true;*/

   /* MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.main5, menu);

    return super.onCreateOptionsMenu(menu);*/
}

请参阅下面的代码：

@Override
public void onCreate(Bundle savedInstanceState) {
    Log.i("LOG", "onCreate");
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    toolbar.setTitle(R.string.app_name);

    //This line is important to show menu
    setSupportActionBar(toolbar);

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.menu_main, menu);
    return super.onCreateOptionsMenu(menu);
}

menu.xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<!-- Single menu item 
     Set id, icon and Title for each menu item
-->
<item android:id="@+id/action_settings"
      android:title="Setting" />    
</menu>

---

post activity onCreate（）方法代码好的，谢谢，但是我应该在哪里使用这个工具栏。我没有在XML中创建它？

// in your activity
@Override
public boolean onCreateOptionsMenu(Menu menu)
{
    MenuInflater menuInflater = getMenuInflater();
    menuInflater.inflate(R.layout.menu, menu);
    return true;
} 

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<!-- Single menu item 
     Set id, icon and Title for each menu item
-->
<item android:id="@+id/action_settings"
      android:title="Setting" />    
</menu>