Android menu system Introduction

If you have tried to use a pen or trackball to navigate the mobile phone menu system, you will know that using a traditional menu system on mobile devices is clumsy.

 

To improve applicationsProgramPracticality of menus,AndroidThree Optimized menu systems are provided for small screens:

 

Bytes Icon menu

WhenMenuThis compact menu (4-4) Is displayed at the bottom of the screen. It shows up6Icons and text menu items (sub menu ).

 

Figure4-4

 

This icon menu does notCheckbox,Radio buttonAnd shortcut keys are displayed as menu items.CheckboxOrRadio buttonAs menu items because they cannot be used.

 

If more6Menu items are defined,MoreMenu items are included. When selected, the extended menu is displayed. PressBackClick to close the icon menu.

 

Bytes Extended menu

When you selectMoreThe extended menu is triggered. Extended menu (4-5) Displays a scroll menu item list (menu items that cannot be visible in the icon menu. This Menu displays all text, shortcuts,CheckboxAndRadio button.

 

Figure4-5

 

Then, it does not display the icon. Therefore, you should avoid specifying icons for menu items that may only appear in the extended menu.

 

PressBackThe button is returned from the extended menuIconMenu.

 

You cannot forceAndroidExtend the menu to replace the icon menu display. Therefore, you need to pay special attention toCheckboxOrRadio buttonMenu items can only be used in extended menus or their status information can be displayed using icons or text.

 

Bytes Sub-menu

The traditional "extended hierarchy tree" is clumsy for mouse navigation, so it is not surprising that it is especially inappropriate to use it on mobile devices.AndroidA floating window is used to display each sub-menu. For example, when you select a graph4-5MarkedSubmenuIts menu items are displayed in a floating menu dialog box,4-6.

 

Figure4-6

 

Note: The Sub-menu name is displayed in the headlines (Header bar), Its sub-menu is displayed as full text,Checkbox(If needed) and shortcut keys. BecauseAndroidNested sub-menus are not supported, so you cannot add sub-menus for sub-menus (attempts may cause exceptions ).

 

Like extended menus, icons are not displayed in sub-menu items. Therefore, it is recommended that you do not specify icons for sub-menu items.

 

PressBackThe button closes the floating window and does not navigate back to the extended menu or icon menu.