"go" android oncreateoptionsmenu () create menu details

<span id="Label3"></p><p><p>Original Url: http://www.linuxidc.com/Linux/2012-02/55500.htm</p></p><p>Android has three different forms of menus:<br>1. Options Menu (optinosmenu)<br>2. context Menu (ContextMenu)<br>3. sub-menu (submenu)<br>The most common of these is the Options menu (optionsmenu), which is displayed at the bottom of the corresponding activity when you click the menu Button.<br><br><strong><strong>1.Activity menu Mechanism</strong></strong>(similar to Dialog)<br>Activity has a mechanism for managing menus, as Follows:<br>1.public Boolean Oncreateoptionsmenu (menu Menu)<br><span><span><code>             此方法用于初始化菜单，其中menu参数就是即将要显示的Menu实例。<br>              返回true则显示该menu,false 则不显示;<br>              </code><strong><code>(只会在第一次初始化菜单时调用)</code></strong><br></span></span><code><code><br><span>           2.public boolean </span></code></code><code><code><span>onPrepareOptionsMenu(Menu menu)<br>             在</span></code></code>Oncreateoptionsmenu is executed, the menu is called before it is displayed, and if the menu is already created, it is called before the menu is Displayed.<br>The same,<code><code><span> 返回true则显示该menu,false 则不显示;<br>             </span><strong>（可以通过此方法动态的改变菜单的状态，比如加载不同的菜单等）<br><br></strong>           3.public void onOptionsMenuClosed(Menu menu)<br>              每次菜单被关闭时调用.<br>              <strong>（</strong></code></code><strong><strong>The menu is closed in three situations where menu button is clicked again, the back button is clicked, or the user selects one of the Menus.</strong></strong><br><br>4.public Boolean onoptionsitemselected (MenuItem Item)<br>The menu item is invoked when clicked, that is, the method of listening for the food Item.<br><br>With these methods, it can be learned that for activity, only one menu object can be displayed and monitored at the same time.<br><br><strong><strong><br>2. Add a menu:</strong></strong><br><strong><strong>can be in Oncreateoptionsmenu or</strong></strong><code><code><span><strong>onPrepareOptionsMenu方法中来添加菜单</strong><br><br></span></code></code><strong><strong>2.1 Code Additions:</strong></strong><br>Menu.add (int groupId, int itemId, int order, charsequence title). setIcon (drawable ID)</p><p><p>The four parameters of the Add () method are, in Turn:</p></p><p><p>1, groups, If not grouped, then write menu.none,</p></p><p><p>2, id, This is very important, Android based on this ID to determine the different menu</p></p><p><p>3, order, which menu item in front by the size of this parameter is determined</p></p><p><p>4, text, menu item display text</p></p><p>The Add () method returns a MenuItem object, calls its SetIcon () method, sets the icon for the corresponding MenuItem<br><br>Example:<br>public boolean Oncreateoptionsmenu (menu Menu) {<br>Super.oncreateoptionsmenu (menu);<br>Menu.add (menu.none,<strong><strong>menu.first+1</strong></strong>, 0, "settings"). SetIcon (r.drawable.setting);<br>Return true;<br>}<br> <br><strong><strong>2.2 Layout file Additions:</strong></strong><br><br>Getmenuinflater (). Inflate (r.menu.options_menu, menu);<br><br>Call Activity's Getmenuinflater () to get a menuinflater,<br>Use the Inflate method to load the defined menu in the Layout file to the menu object corresponding to the second parameter<br><br>Example:<br>@Override<br>public boolean Oncreateoptionsmenu (menu Menu) {<br>Super.oncreateoptionsmenu (menu);<br>Getmenuinflater (). Inflate (<strong><strong>R.menu.options_menu</strong></strong>, menu);<br>Return true;<br>}<br><br>Layout file:<br>Set up a menu folder in the Res directory and create a layout file: options_menu.xml<br><?xml version= "1.0" encoding= "utf-8"?><br><menu xmlns:android= "http://schemas.android.com/apk/res/android" ><br><item android:id= "<strong><strong>@+id/menu_setting</strong></strong>"android:title=" setting "android:icon=" @drawable/setting "></item><br></menu><br><br><br><strong><strong>3. menu item Monitoring:</strong></strong><br>Onoptionsitemselected (MenuItem Item) is triggered whenever a menu item in the menu is clicked<br>The item parameter is the menu item that is clicked, so it is necessary to determine which item is clicked in this method, thus implementing different actions.<br>For the two different ways to add a menu, the method of judging is a little different, but the essence is the Same.<br><br><strong><strong>3.1 How to determine the code to add a menu</strong></strong><br>@Override<br>public boolean onoptionsitemselected (MenuItem Item) {<br>Super.onoptionsitemselected (item);<br>Switch (item.getitemid ())//get clicked on the Item's itemid<br>{<br>Case<strong><strong>menu.first+1</strong></strong>://ID is the ID set in the Add method<br>Break<br>Case Menu.first+2:<br>Break<br>}<br>Return true;<br>}<br><br><strong><strong>3.2 How to determine the layout file add menu:</strong></strong><br>@Override<br>public boolean onoptionsitemselected (MenuItem Item) {<br>Super.onoptionsitemselected (item);<br>Switch (item.getitemid ())//get clicked on the Item's itemid<br>{<br>Case<strong><strong>r.id.menu_setting</strong></strong>://the ID here is the ID defined in the layout file, which is obtained by means of r.id.xxx<br>Break<br>Case R.id.menu_info:<br>Break<br>}<br>Return true;<br>}</p><p><p>"go" android oncreateoptionsmenu () create menu details</p></p></span>