Android各种屏幕的分布率以及自适应各种屏幕的开发研究

下图表明了现在持有Android设备的屏幕分辨率的大概的一个分布，从中可看到mdpi跟hdpi的nomal分类占据了84%！所以我们的程序最开始要尽量适应这俩种设备。

Data collected during a 7-day period ending on May 1, 2012

​	ldpi	mdpi	hdpi	xhdpi
small	2.3%	​	2.4%	​
normal	0.7%	26.2%	57.8%	0.9%
large	0.3%	2%	​	​
xlarge	​	7.4%	​	​

那么下图则给出了各种分辨率屏幕的对应关系，标注红色的部分就是我们需要关心的。他们分别位于mdpi跟hdpi。

**Table 3.**Various screen configurations available from emulator skins in the Android SDK (indicated in bold) and other representative resolutions.

​	Low density (120), ldpi	Medium density (160), mdpi	High density (240), hdpi	Extra high density (320), xhdpi
_Small_screen	QVGA (240x320)	​	480x640	​
_Normal_screen	**WQVGA400 (240x400)
WQVGA432 (240x432)**	HVGA (320x480)	**WVGA800 (480x800)
WVGA854 (480x854)**
600x1024	640x960
_Large_screen	WVGA800 (480x800)
WVGA854** (480x854)**	*WVGA800 (480x800)
WVGA854* (480x854)**
600x1024	​	​
_Extra Large_screen	1024x600	WXGA (1280x800)†
1024x768
1280x768	1536x1152
1920x1152
1920x1200	2048x1536
2560x1536
2560x1600

• _xlarge_screens are at least 960dp x 720dp

• _large_screens are at least 640dp x 480dp

• _normal_screens are at least 470dp x 320dp

• _small_screens are at least 426dp x 320dp

那么如何针对mdpi跟hdpi做开发呢？我们通常在编写布局文件的时候碰到ps，dp等单位，建议大家使用dp来自适应各种屏幕，下面是dp对应屏幕分辨率：

• 320dp: a typical phone screen (240x320 ldpi,320x480 mdpi,480x800 hdpi, etc).

• 480dp: a tweener tablet like the Streak (480x800 mdpi).

• 600dp: a 7” tablet (600x1024 mdpi).

• 720dp: a 10” tablet (720x1280 mdpi, 800x1280 mdpi, etc).

其中计算公式是:px = dp * (dpi / 160)

参考：http://developer.android.com/resources/dashboard/screens.html

http://developer.android.com/guide/practices/screens_support.html