[Excerpt] Android screen resolution

The iPhone's icon design is so simple that the iPhone's screen is only 320x480 pixels, soProgramNo adaptability issues.

Android

Before studying the android icon design, it is necessary to first understand how the android interface adapts to a variety of screens.

Adaptability

Because the same UI element (such as a 100 x pixel image) looks smaller on a high-precision screen than on a low-precision screen, to make the images on these two screens look similar, you can use the following two methods:

Scale the image in ascending order, but the effect is poor.
Provide an image for each of the two precision screens.

However, the screen parameters are diversified, and a set of icons is designed for each precision screen, which requires a lot of work and cannot meet the compatibility requirements of the program, so it is necessary to classify the screen, for example, if you use the same set of icons on the screen of a DPI and DPI mobile phone, you need to create another set of larger icons when the DPI icon does not meet the design requirements.

 

In Android 1.5 and earlier versions, only the hvga (3.2x320) Resolution on the 480 "screen is supported, and developers do not need to consider the adaptability of the interface. Since Android 1.6, the platform supports devices of various sizes and resolutions, which means developers should consider the diversity of screens during design.

To simplify the design and be compatible with more mobile phone screens, the platform distinguishes the screens by size and resolution:

Three sizes: large, medium, and small.
Three types of precision: high (hdpi), medium (mdpi), and low (ldpi ).

The program can provide default resources for screens of these three sizes. If necessary, it can also provide resources for screens of various precision. During running, the system loads images of the correct size or accuracy based on the screen layout.

Android Icon size

At runtime, the program provides three methods for optimal display:

1. Image Scaling

Based on the precision of the current screen, the platform automatically loads any images with limited sizes and precision without scaling. If the image does not match, the platform loads the default resources and the display requirements of the current interface can be met after the image is zoomed in or out. For example, if the screen is a high-precision screen, the platform loads high-precision resources (slices). If not, the platform scales the medium-precision resources to a high-precision value.

2. automatically define the pixel size and position

If the program does not support multiple precision screens, the platform automatically defines the absolute position and size values of pixels, in this way, the elements can be displayed in the same size as those on the screen with an accuracy of 160. For example, to make the WVGA high-precision screen display the same size as the traditional hvga screen, when the program does not support it, the system will say that the screen resolution of the program is 320 × 533, after the drawing is completed in the (100,100) to (150,150) area, the system will enlarge the drawing to the (15, 15) to () screen display area.

3. Screens of larger sizes

When the current screen exceeds the upper limit of the screen supported by the program, the supports-screens element is defined, so that when the display baseline is exceeded, the platform displays a black background image here. For example, on a WVGA precision screen, if the program does not support such a large screen, the system will lie that it is 320 × 480, and the excess display area will be filled with black.

But in order to achieve the best display effect, the best way is to design multiple sets of images. Then it is necessary to classify all screens based on their precision values (high and low), and then design three icons:

First, design an icon for the mainstream precision screen (hvga) to determine the pixel size of the image.
Scale down an image to 150% for a high-precision screen and to 75% for a low-precision screen.
Place the three resource sources in three folders of the program: Res/drawable-mdpi/, Res/drawable-hdpi/, and Res/drawable-ldpi /. When the program is running, the platform will adjust the appropriate icon according to the screen precision.

Design Guide

Android standard icon

Launcher icon is a functional icon on the main interface of the program. Android has certain requirements on the style of each icon:

In line with the current trend, avoid over-Using metaphor.
High simplification and exaggeration, small icons can also be easily identified, not too complicated.
Try to grasp the main features of the program, such as audio and video as the icon of music.
The use of natural outlines and shapes looks geometric and organic, without losing the sense of reality.
The icon uses a front-angle, with almost no perspective, and the light source is on the top.
Not smooth but texture-rich.

Correct and wrong icons

In addition, all icons have text labels. Do not put the text in the icon during design.

Launcher icon is usually a large standard icon that contains a small icon, using a neutral color and a major color, and maintain a high contrast, should not be too saturated.

Recommended color value

Dimensions and positioning

Launcher icons needs to have a variety of shapes and styles, but also to form a unified visual style, its size and positioning are also unified:

(Full asset) the red border is the icon size
(Icon) the blue border is the image size, which is slightly smaller than the Icon size. spaces outside the image are used to display shadows and special effects.
(Square icon) the orange border is another image size. The two types of image sizes can achieve a unified visual weight.

Icon dimensions for high-density (hdpi) screens:

Full asset: 72X72 PX
Icon: 60x60 PX
Square icon: 56x56 PX

Icon dimensions for medium-density (mdpi) screens:

Full asset: 48x48 PX
Icon: 40x40 PX
Square icon: 38X3

Icon dimensions for low-density (ldpi) screens:

Full asset: 36x36 PX
Icon: 30x30 PX
Square icon: 28x28 PX

Template

Download the standard icon template of Android, draw the icon on this basis, and add the shadow effect later.

WVGA (High Precision) screen shadow:

Effect: Drop Shadow
Color: #000000.
Blend mode: multiply
Opacity: 75%
Angle: 90 °
Distance: 2px
Spread: 0%
Size: 5px

For more information about how to design menu icon, status bar icon, Tab icon, dialog icon, and list view icon, see the original document.

A very detailed icon design tutorial. Three icons should be placed in a program, and the Android hardware is better, otherwise the memory will pop up.