Android动态修改ToolBar的Menu菜单示例

<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.kongqw.myapplication.MainActivity">  <item    android:id="@+id/search_button"    android:icon="@mipmap/navigation_icon_search"    android:orderInCategory="100"    android:title="搜索"    app:showAsAction="ifRoom" />  <item    android:id="@+id/scan_button"    android:icon="@mipmap/navigation_icon_sweep"    android:orderInCategory="100"    android:title="扫描"    app:showAsAction="ifRoom" />  <item    android:id="@+id/setting_button"    android:icon="@mipmap/titlebar_icon_settings_normal"    android:orderInCategory="100"    android:title="设置"    app:showAsAction="ifRoom" /></menu>

@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);}

@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);}

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) {  }});

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;    }  }}