Summary of usage of menu in Android project

1. The normal menu

Let's see how the simplest menu is implemented.

Overrides the Oncreateoptionsmenu (Menu menu) method in the main activity.

Code@Override
public boolean Oncreateoptionsmenu (Menu menu) {
TODO auto-generated Method Stub
Menu.add (0, 1, 1, "Apple");
Menu.add (0, 2, 2, "banana");
return Super.oncreateoptionsmenu (menu);
}

This will have two menu options. If you want to add a click event, overwrite the onoptionsitemselected (MenuItem Item) method.

Code@Override
public boolean onoptionsitemselected (MenuItem item) {
TODO auto-generated Method Stub
if (item.getitemid () = = 1) {
Toast T = toast.maketext (This, "You chose Apple", Toast.length_short);
T.show ();
}
else if (item.getitemid () = = 2) {
Toast T = toast.maketext (This, "You have chosen Bananas", toast.length_short);
T.show ();
}
return true;
}

2. Submenu

The production of submenu is also simple, add a few sentences to the first code oncreateoptionsmenu (Menu menu) method, as follows:

Code@Override
public boolean Oncreateoptionsmenu (Menu menu) {
TODO auto-generated Method Stub
Menu.add (0, 1, 1, "Apple");
Menu.add (0, 2, 2, "banana");
Submenu submenu = Menu.addsubmenu (1, 100, 100, "peach");
Submenu.add (2, 101, 101, "Big Peach");
Submenu.add (2, 102, 102, "Little Peach");
return true;
}

Click "Peach" will appear submenu, there are two sub-options, respectively, "Big peach" and "small peach."

3. Context Menu

Similar to the right mouse button on your computer, press and hold the menu that pop up after a view.

First, define a number of buttons in the Main.xml. Then overwrite the Oncreatecontextmenu (ContextMenu menu, View V, Contextmenuinfo menuinfo) method. The code inside is as follows:

First, to register, in the OnCreate method, the following code:

Code@Override
public void OnCreate (Bundle savedinstancestate) {
Super.oncreate (savedinstancestate);
Setcontentview (R.layout.main);
B1 = (Button) Findviewbyid (R.ID.B1);
B2 = (Button) Findviewbyid (R.ID.B2);
Registerforcontextmenu (B1);
Registerforcontextmenu (B2);
}

Code@Override
public void Oncreatecontextmenu (ContextMenu menu, View V,
Contextmenuinfo menuinfo) {
TODO auto-generated Method Stub
if (V==B1) {
Menu.setheadertitle ("This is 1");
Menu.add (A. 1, "Context menu,");
Menu.add (201, 201, "Context menu 2");
}
else if (V==B2) {
Menu.setheadertitle ("This is 2");
Menu.add (b, 1);
Menu.add (301, 301, "C 2");
}
Super.oncreatecontextmenu (menu, V, menuinfo);
}

4. Dynamic Menu

Dynamic menus have different menus depending on the interface. The following code implements this function: when the value of a TextView in the main interface is "M" and "N", a different menu pops up.

Code@Override
public boolean Onprepareoptionsmenu (Menu menu) {
TODO auto-generated Method Stub
String Currenttext = Tv1.gettext (). toString ();
if ("M". Equals (Currenttext)) {
Menu.clear ();//Clear out the menu first
MenuItem item = menu.add (0, +, 401, "to N");//You can change the value of the TV1 by clicking on the menu item (n) to test the
Item.seticon (Android. R.drawable.alert_dark_frame);//android's own icon
}
if ("N". Equals (Currenttext)) {
Menu.clear ();//Clear out the menu first
MenuItem item = menu.add (0, 401, 402, "to M");//You can change the value of the TV1 by clicking on the menu item so that you can test it (into m).
Item.seticon (Android. R.drawable.alert_light_frame);
}
Menu.add (0, 402, 403, "now is" + currenttext);//There are two menu subkeys
return Super.onprepareoptionsmenu (menu);
}

　　

5. Create a menu in XML file mode

Previously, the menu was created in code, and it was easy to make menus with an XML configuration file.

To res/directory to build a folder, named menu, the following an XML file, named Menu_xml_file.xml, the code is as follows:

Code<?xml version= "1.0" encoding= "Utf-8"?>
<menu xmlns:android= "Http://schemas.android.com/apk/res/android" >
<group android:id= "@+id/grout_main" >
<item android:id= "@+id/menu_1"
Android:title= "This 1"/>
<item android:id= "@+id/menu_2"
Android:title= "This 2"/>
</group>
</menu>

In the activity, overwrite the Oncreateoptionsmenu (Menu menu) method with the following code:

Code@Override
public boolean Oncreateoptionsmenu (Menu menu) {
TODO auto-generated Method Stub
Menuinflater inflater = Getmenuinflater ();
Inflater.inflate (r.menu.menu_xml_file, menu);
return true;
}

The rest is the same as creating a menu in activity.