Mobile Programming (Android) — Multiple Screen Lifecycle Intent
Drawable — Images
Pixels
> the exact number of dots both horizontally and vertically that make up the file.
> this the actual resolution of the file.
DPI (Dots Per Inch)
> the number of dots or pixels per each inch of a printed or scanned document.
Density-independent Pixel (dp)
> A virtual pixel unit that we should use when defining UI layout to express layout dimensions or position in a density-independent way.
> px = dp*(dpi/160)
dp
> Density-independent pixel
> 1 dp = 1 pixel on a 160 dpi screen
sp
> scale-indepent pixel
> similar to dp and is recommended for specifying font sizes
px
> Pixel
> corresponds to actual pixels on the screen
Six generalised densities
> mdpi(medium) ~ 160dpi
> hdpi (high) ~ 240dpi
> xhdpi (extra-high) ~ 320dpi