android 中dip sp的施用
Historically, programmers always designed computer interfaces in terms of pixels. For example, you mightmake a field 300 pixels wide, allow 5 pixels of spacing between columns, and define icons 16-by-16 pixels in size. The problem is that if you run that program on new displays with more and more dots per inch (dpi), the user interface appears smaller and smaller. At some point, it becomes too hard to read. Resolution-independent measurements help solve this problem.
Android supports all the following units:
• px (pixels): Dots on the screen.
• in (inches): Size as measured by a ruler.
• mm (millimeters): Size as measured by a ruler.
• pt (points): 1/72 of an inch.
• dp (density-independent pixels): An abstract unit based on the density of the screen. On a display with 160 dots per inch, 1dp = 1px.
• dip: Synonym for dp, used more often in Google examples.
• sp (scale-independent pixels): Similar to dp but also scaled by the user’s font size preference.
To make your interface scalable to any current and future type of display, I recommend you always use the sp unit for text sizes and the dip unit for everything else. You should also consider using vector graphics instead of bitmaps
dip就是dp
dip是密度不相关像素。为了适应有的屏幕大有的屏幕小。为了达到统一的显示效果。
sp是字体推荐使用的，也会适应手机的字体大小
作为图片最好使用的是矢量图，9.png。而不要使用位图。