android Menu菜单的使用

<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="com.datong.diaplaymetrics.MainActivity">
<item
android:id="@+id/action_settings1"
android:orderInCategory="100"
android:title="@string/action_settings1"
app:showAsAction="never"/>
<item
android:id="@+id/action_settings2"
android:orderInCategory="100"
android:title="@string/action_settings3"
app:showAsAction="never"/>
<item
android:id="@+id/action_settings3"
android:orderInCategory="100"
android:title="@string/action_settings3"
app:showAsAction="never"/>
<item
android:id="@+id/action_settings4"
android:orderInCategory="100"
android:title="@string/action_settings4"
app:showAsAction="never"/>
</menu>

package com.datong.diaplaymetrics;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
//        setSupportActionBar(toolbar);
//
//        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
//        fab.setOnClickListener(new View.OnClickListener() {
//            @Override
//            public void onClick(View view) {
//                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
//                        .setAction("Action", null).show();
//            }
//        });
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();

//noinspection SimplifiableIfStatement
switch (id){
case R.id.action_settings1:
Toast.makeText(MainActivity.this,"action_settings1",Toast.LENGTH_LONG).show();
break;
case R.id.action_settings2:
Toast.makeText(MainActivity.this,"action_settings2",Toast.LENGTH_LONG).show();
break;
case R.id.action_settings3:
Toast.makeText(MainActivity.this,"action_settings3",Toast.LENGTH_LONG).show();
break;
case R.id.action_settings4:
Toast.makeText(MainActivity.this,"action_settings4",Toast.LENGTH_LONG).show();
break;
}

return super.onOptionsItemSelected(item);
}
}