The nUINavbuttonElement object is a android.view.MenuItem class. For more information, see Menus.

When you use the nUINavbuttonElement object in a nUINavView object, at least the Text or the Icon attributes must be supplied.

When you use the nUINavbuttonElement object in a nUIViewDisplay object:

The button displays in the header bar. This support is only available if android.nativeui.view.header.version is set to the newer style header bar introduced with Ice Cream Sandwich.

If you set the Type attribute to nUINavbuttonElement.TYPE_BACK, if the Android device has a physical Back button, the Back button is used. Otherwise, if the newer style header bar introduced with Ice Cream Sandwich is in use, Android draws a Back button in the header.

If you use the HeaderText attribute and space is not available for both the header text and the nUINavbuttonElement objects, the header text is truncated.

It is recommended that you insert no more than 3 nUINavbuttonElement objects in a nUIViewDisplay object.

The Icon attribute is required. The icon will be used if it is supplied. If not, the Text attribute is used instead. Please provide a brief text for the attribute because the text will be cropped at a width 1.5 times the width of the standard Icon width.

The size of the image you specify with the Icon attribute for a pop-up menu is based on the density of the screen of the device:

Low density (ldpi) images is 36x36 pixels.

Medium density (mdpi) images is 48x48 pixels.

High density (hdpi) images is 72x72 pixels.

The size of the image you specify with the Icon attribute for an action bar is based on the density of the screen of the device:

Medium density (mdpi) images is 32x32 pixels.

High density (hdpi) images is 48x48 pixels.

Extra high density (xdpi) images is 64x64 pixels.

The nUINavbuttonElement object is a UITabBarItem class.

When you use the nUINavbuttonElement object in a nUINavView object:

The Text and Icon attributes are required.

When specifying an image with the Icon attribute, the image should be 32x32 pixels for a non-Retina display or 64x64 pixels for a Retina display. Additionally, the image should be black on transparent. The iOS device automatically adds highlighting and gradients at run time.

When you use the nUINavbuttonElement object in a nUIViewDisplay object:

The button displays in the header bar.

If you set the Type attribute to nUINavbuttonElement.TYPE_BACK, the button displays in the left of the header.

The Icon or Text attribute is required. If you specify both, Icon is used.

If you specify only the Text attribute, the iOS devices draws the text inside a button.

When specifying an image with the Icon attribute, it is recommended that the image be 24x24 pixels for a non-Retina display or 48x48 pixels for a Retina display. The iOS device draws the icon without additional borders.

If you use the HeaderText attribute and space is not available for both the header text and the nUINavbuttonElement objects, the header text is truncated.

For an iPhone running iOS, it is recommended that you insert no more than 3 nUINavbuttonElement objects in a nUIViewDisplay object.

For an iPad running iOS, it is recommended that you insert no more than 6 nUINavbuttonElement objects in a nUIViewDisplay object.

The nUINavbuttonElement object is a ApplicationBarIconButton or ApplicationBarMenuItem class.

When you use the nUINavbuttonElement object in a nUINavView object:

The Text and Icon attributes are required. For more information, see Application Bar Overview for Windows Phone.

When specifying an image with the Icon attribute, the image should be 27x27 pixels. Additionally, the image should be white on transparent. The Windows Phone device automatically adds the circle around the icon at run time.

When you use the nUINavbuttonElement object in a nUIViewDisplay object:

The button displays in a pop-up menu.

If you set the Type attribute to nUINavbuttonElement.TYPE_BACK, the Windows Phone device uses the physical Back button and does not draw a Back button.

The Text attribute is required.

You can insert any number of nUINavbuttonElement objects in a nUIViewDisplay object.

The nUINavbuttonElement object is a Windows.UI.Xaml.Controls.Button class.

When specifying an image with the Icon attribute, the image should be 48x48 pixels. When you use the nUINavbuttonElement object in a nUINavView object, the Windows RT/Windows 8 device automatically adds the circle around the icon at run time. Otherwise, you have to add the circle yourself.

You can insert any number of nUINavbuttonElement objects in a nUINavView or nUIViewDisplay object, limited only by the screen width.

When you use the nUINavbuttonElement object in a nUINavView object, the Text and Icon attributes are required.

When you use the nUINavbuttonElement object in a nUIViewDisplay object:

The button displays in the header bar.

The Icon attribute is required.