Getting Started with Android (15) Using Menu 15.1 helper methods

Menus can be used to display additional options that do not have to appear in the main interface. In the Android framework, there are 2 main types of menus:

Options menu--Displays information about the current activity. Use the menu key to trigger the menus.

Context menu--Displays information related to one view in the activity. Long press a view to trigger this menu.

On the left is the option menu, and the right side is the context menu.

Before using both menus, let's start with two helper methods. A list of options to populate the menu, and another to handle the menu's selected events.

1. Create a project: Menus.

2. Code in the Menusactivity.java.

The public class Menusactivity extends activity {/** called the ' when ' is the ' The activity ' is the ' the '---' @Override    
        public void OnCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate);    
    Setcontentview (R.layout.main);    
        } private void CreateMenu (Menu menu) {Menu.setqwertymode (true);    
        MenuItem mnu1 = menu.add (0, 0, 0, "Item 1");    
            {mnu1.setalphabeticshortcut (' a ');    
        Mnu1.seticon (R.drawable.ic_launcher);    
        MenuItem mnu2 = menu.add (0, 1, 1, "Item 2");    
            {mnu2.setalphabeticshortcut (' B ');    
        Mnu2.seticon (R.drawable.ic_launcher);    
        MenuItem mnu3 = menu.add (0, 2, 2, "Item 3");    
            {mnu3.setalphabeticshortcut (' C ');    
        Mnu3.seticon (R.drawable.ic_launcher);    
      MenuItem mnu4 = menu.add (0, 3, 3, "Item 4");  {mnu4.setalphabeticshortcut (' d ');    
        } menu.add (0, 4, 4, "Item 5");    
        Menu.add (0, 5, 5, "Item 6");    
    Menu.add (0, 6, 6, "Item 7");    
            Private Boolean Menuchoice (MenuItem item) {switch (Item.getitemid ()) {case 0:    
            Toast.maketext (This, "Your clicked on Item 1", Toast.length_long). Show ();    
        return true;    
            Case 1:toast.maketext (this, "Your clicked on Item 2", Toast.length_long). Show ();    
        return true;    
            Case 2:toast.maketext (this, "Your clicked on Item 3", Toast.length_long). Show ();    
        return true;    
            Case 3:toast.maketext (this, "Your clicked on Item 4", Toast.length_long). Show ();    
        return true; Case 4:toasT.maketext (This, "Your clicked on Item 5", Toast.length_long). Show ();    
        return true;    
            Case 5:toast.maketext (this, "Your clicked on Item 6", Toast.length_long). Show ();    
        return true;    
            Case 6:toast.maketext (this, "Your clicked on Item 7", Toast.length_long). Show ();    
        return true;    
    return false; }    
       
}

In the above example, there are 2 main methods: CreateMenu () and Menuchoice ().

CreateMenu () method, receives a parameter of a menu type, and adds some menu items to the parameter.

To add a menu item, we will create an instance of the MenuItem class and then use the Add () method of the Menu object.

MenuItem mnu1 = menu.add (0, 0, 0, 

"Item 1");    
{    
    mnu1.setalphabeticshortcut (' a ');    
    Mnu1.seticon (R.drawable.ic_launcher);    
}

The Add () method has 4 parameters, which I Yi Yilai explain:

groupid--If a menu item is in a group, this is the identifier for the group. If GroupID is 0, the menu item is not in any group.

Unique identification of the itemid--menu item.

order--the order in which menu items are displayed.

title--the display text for the menu item.

Alternatively, we can use the Setalphabeticshortcut () method to set a shortcut key. This allows you to use the keyboard to select a menu item.

The SetIcon () method lets you set a picture for a menu item.

Finally, the Menuchoice () method receives a MenuItem type parameter and then checks its ID to determine which menu item is selected, and pops up a toast notification to tell the user which menu item he has selected.