Android动态修改ToolBar的Menu菜单
效果图
实现
实现很简单，就是一个具有3个Action的Menu，在我们滑动到不同状态的时候，把对应的Action隐藏了。
开始上货
Menu
Menu下添加3个Item
重写onPrepareOptionsMenu方法
用来根据ViewPager显示页面控制Menu显示的Item
Demo里我用的是ViewPager滑动来控制，可以根据自己需求，不过大多数都是判断ViewPager吧。
@Overridepublic boolean onPrepareOptionsMenu(Menu menu) { // 动态设置ToolBar状态 switch (mViewPager.getCurrentItem()) { case 0: menu.findItem(R.id.search_button).setVisible(true); menu.findItem(R.id.scan_button).setVisible(true); menu.findItem(R.id.setting_button).setVisible(false); break; case 1: menu.findItem(R.id.search_button).setVisible(false); menu.findItem(R.id.scan_button).setVisible(false); menu.findItem(R.id.setting_button).setVisible(false); break; case 2: menu.findItem(R.id.search_button).setVisible(false); menu.findItem(R.id.scan_button).setVisible(false); menu.findItem(R.id.setting_button).setVisible(true); break; } return super.onPrepareOptionsMenu(menu);} Item点击
@Overridepublic boolean onOptionsItemSelected(MenuItem item) { int id = item.getItemId(); if (id == R.id.search_button) { Toast.makeText(getApplicationContext(), "搜索", Toast.LENGTH_SHORT).show(); return true; } else if (id == R.id.scan_button) { Toast.makeText(getApplicationContext(), "扫描", Toast.LENGTH_SHORT).show(); return true; } else if (id == R.id.setting_button) { Toast.makeText(getApplicationContext(), "设置", Toast.LENGTH_SHORT).show(); return true; } return super.onOptionsItemSelected(item);} 监听ViewPager滑动，改变Menu状态（重点）
调用invalidateOptionsMenu();方法从新加载Menu，即回调onPrepareOptionsMenu方法
mViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() { @Override public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { } @Override public void onPageSelected(int position) { // getWindow().invalidatePanelMenu(Window.FEATURE_OPTIONS_PANEL); invalidateOptionsMenu(); } @Override public void onPageScrollStateChanged(int state) { }}); Code（参考）
就是Android Studio默认创建的带有ViewPager的Demo，
package com.kongqw.myapplication;import android.support.v7.app.AppCompatActivity;import android.support.v7.widget.Toolbar;import android.support.v4.app.Fragment;import android.support.v4.app.FragmentManager;import android.support.v4.app.FragmentPagerAdapter;import android.support.v4.view.ViewPager;import android.os.Bundle;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.TextView;import android.widget.Toast;public class MainActivity extends AppCompatActivity { private SectionsPagerAdapter mSectionsPagerAdapter; private ViewPager mViewPager; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); setSupportActionBar(toolbar); mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager()); mViewPager = (ViewPager) findViewById(R.id.container); mViewPager.setAdapter(mSectionsPagerAdapter); mViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() { @Override public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { } @Override public void onPageSelected(int position) { // getWindow().invalidatePanelMenu(Window.FEATURE_OPTIONS_PANEL); invalidateOptionsMenu(); } @Override public void onPageScrollStateChanged(int state) { } }); } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.menu_main, menu); return true; } @Override public boolean onPrepareOptionsMenu(Menu menu) { // 动态设置ToolBar状态 switch (mViewPager.getCurrentItem()) { case 0: menu.findItem(R.id.search_button).setVisible(true); menu.findItem(R.id.scan_button).setVisible(true); menu.findItem(R.id.setting_button).setVisible(false); break; case 1: menu.findItem(R.id.search_button).setVisible(false); menu.findItem(R.id.scan_button).setVisible(false); menu.findItem(R.id.setting_button).setVisible(false); break; case 2: menu.findItem(R.id.search_button).setVisible(false); menu.findItem(R.id.scan_button).setVisible(false); menu.findItem(R.id.setting_button).setVisible(true); break; } return super.onPrepareOptionsMenu(menu); } @Override public boolean onOptionsItemSelected(MenuItem item) { int id = item.getItemId(); if (id == R.id.search_button) { Toast.makeText(getApplicationContext(), "搜索", Toast.LENGTH_SHORT).show(); return true; } else if (id == R.id.scan_button) { Toast.makeText(getApplicationContext(), "扫描", Toast.LENGTH_SHORT).show(); return true; } else if (id == R.id.setting_button) { Toast.makeText(getApplicationContext(), "设置", Toast.LENGTH_SHORT).show(); return true; } return super.onOptionsItemSelected(item); } public static class PlaceholderFragment extends Fragment { private static final String ARG_SECTION_NUMBER = "section_number"; public PlaceholderFragment() { } public static PlaceholderFragment newInstance(int sectionNumber) { PlaceholderFragment fragment = new PlaceholderFragment(); Bundle args = new Bundle(); args.putInt(ARG_SECTION_NUMBER, sectionNumber); fragment.setArguments(args); return fragment; } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View rootView = inflater.inflate(R.layout.fragment_main, container, false); TextView textView = (TextView) rootView.findViewById(R.id.section_label); textView.setText(getString(R.string.section_format, getArguments().getInt(ARG_SECTION_NUMBER))); return rootView; } } public class SectionsPagerAdapter extends FragmentPagerAdapter { public SectionsPagerAdapter(FragmentManager fm) { super(fm); } @Override public Fragment getItem(int position) { return PlaceholderFragment.newInstance(position + 1); } @Override public int getCount() { return 3; } @Override public CharSequence getPageTitle(int position) { switch (position) { case 0: return "SECTION 1"; case 1: return "SECTION 2"; case 2: return "SECTION 3"; } return null; } }}