Android動態修改ToolBar的Menu菜單
效果圖
實現
實現很簡單，就是一個具有3個Action的Menu，在我們滑動到不同狀態的時候，把對應的Action隱藏了。
開始上貨
Menu
Menu下添加3個Item
<menu xmlns:android/217023.html">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="掃描" app:showAsAction="ifRoom" /> <item android:id="@+id/setting_button" android:icon="@mipmap/titlebar_icon_settings_normal" android:orderInCategory="100" android:title="設置" app:showAsAction="ifRoom" /></menu>
重寫onPrepareOptionsMenu方法
用來根據ViewPager顯示頁面控制Menu顯示的Item
Demo里我用的是ViewPager滑動來控制，可以根據自己需求，不過大多數都是判斷ViewPager吧。
@Overridepublic boolean onPrepareOptionsMenu(Menu menu) { // 動態設置ToolBar狀態 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點擊
@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(), "掃描", Toast.LENGTH_SHORT).show(); return true; } else if (id == R.id.setting_button) { Toast.makeText(getApplicationContext(), "設置", Toast.LENGTH_SHORT).show(); return true; } return super.onOptionsItemSelected(item);}監聽ViewPager滑動，改變Menu狀態（重點）
調用invalidateOptionsMenu();方法從新加載Menu，即回調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（參考）
就是Android Studio默認創建的帶有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) { // 動態設置ToolBar狀態 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(), "掃描", Toast.LENGTH_SHORT).show(); return true; } else if (id == R.id.setting_button) { Toast.makeText(getApplicationContext(), "設置", 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; } }}以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持VEVB武林網。
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