github上找到一个不错的demo

activity中使用的主题

 <style name="AppTheme.Base" parent="Theme.AppCompat">
        <item name="windowActionBar">false</item>
        <item name="windowNoTitle">true</item>
    </style>

 <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=".MainActivity">
     <item
         android:id="@+id/action_search"
         android:orderInCategory="4"
         android:title="@string/action_settings"
         app:actionViewClass="android.support.v7.widget.SearchView"
         app:showAsAction="always" />
     <item
         android:id="@+id/action_settings"
         android:orderInCategory="1"
         android:title="@string/action_settings"
         app:showAsAction="always" />
 </menu>

布局

 <LinearLayout 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"
     android:id="@+id/container"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:orientation="vertical"
     tools:context=".MainActivity"
     tools:ignore="MergeRootFrame">
     <?xml version="1.0" encoding="utf-8"?>
     <android.support.v7.widget.Toolbar
         android:id="@+id/id_tool_bar"
         android:layout_width="match_parent"
         android:layout_height="?attr/actionBarSize"
         android:background="?attr/colorPrimary"
         android:navigationContentDescription="back"></android.support.v7.widget.Toolbar><!--  ?attr/homeAsUpIndicator-->

     <TextView
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:text="@string/hello_world" />

     <android.support.v7.widget.SearchView
         android:id="@+id/SearchView"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:background="@drawable/abc_ic_menu_copy_mtrl_am_alpha"
         app:goIcon="@drawable/ic_launcher"></android.support.v7.widget.SearchView>
 </LinearLayout>

 package com.anand.toolbardemo;

 import android.content.Intent;
 import android.os.Bundle;
 import android.support.v4.app.Fragment;
 import android.support.v7.app.AppCompatActivity;
 import android.support.v7.widget.SearchView;
 import android.support.v7.widget.Toolbar;
 import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.Window;
 import android.widget.Toast;


 public class MainActivity extends AppCompatActivity implements SearchView.OnQueryTextListener, View.OnClickListener {

     private Toolbar toolbar;

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
         toolbar = (Toolbar) findViewById(R.id.id_tool_bar);
 //        getSupportActionBar().setDisplayShowHomeEnabled(true);
 //        toolbar.setNavigationIcon(R.drawable.ic_launcher);
         setSupportActionBar(toolbar);
         getSupportActionBar().setDisplayHomeAsUpEnabled(true);
         getSupportActionBar().setDisplayShowTitleEnabled(false);

        SearchView sv= (SearchView) findViewById(R.id.SearchView);
         sv.setSubmitButtonEnabled(true);
     }

     @Override
     protected void onActivityResult(int requestCode, int resultCode, Intent data) {
         super.onActivityResult(requestCode, resultCode, data);
     }

     private void toast(String str) {
         Toast.makeText(this, str, Toast.LENGTH_SHORT).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);
         SearchView sv = (SearchView) menu.findItem(R.id.action_search).getActionView();
         sv.setOnSearchClickListener(this);
         sv.setOnQueryTextListener(this);
         sv.setSubmitButtonEnabled(true);
         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
         if (id == R.id.action_settings) {
             toast("action_settings");
         } else if (id == android.R.id.home) {
             toast("home");
         } else if (id == R.id.action_search) {
             toast("action_search");
             // item.collapseActionView();
             //是搜索框默认展开
 //            SearchView sv = (SearchView) item.getActionView(); //空指针
 //
 //            item.expandActionView();
         }

         return super.onOptionsItemSelected(item);
     }

     @Override
     public boolean onQueryTextSubmit(String query) {
         toast("onQueryTextSubmit:" + query);
         return true;
     }

     @Override
     public boolean onQueryTextChange(String newText) {
         toast("onQueryTextSubmit:" + newText);
         return true;
     }

     @Override
     public void onClick(View v) {
         toast("onClick:" + v.getId());
     }

     private void log(String s) {
         Log.d(getClass().getSimpleName() + "->log->>", s);
     }

 }