What is control layoutThe so-called control layout method refers to the method that controls the position, size, color, and other control style properties of the control within the activity.
control layout, in Android, there are two methods:1. Use layout file to complete control layout (relatively simple) 2, complete control layout in Java code (dynamic layout, more flexible, and relatively complex)
Layout Method Classification1.Linear Layout(easiest to master) Linear layout: can be arranged vertically or horizontally. 2.ralative Layout(most commonly used, familiar with web development is familiar) 3,ListView4.Grid View
length units and internal and external margins
Length UnitsPS: Pixel pxDPI: Number of dots per inch (dpi = radical (height^2 + width^2) ÷size) (size in inches)DP: DP = Dip (device independent pixels) equipment-independent pixels, often used to set the size of the control. Conversion formula PX = DP * (dpi/160) on screen with dpi (pixels per inch) of 160:1DP = 1pxSP: scaled pixels SP units are typically used to specify the size of the font when the user modifies the system font size, the font size changes.
internal and external margins"===================================end================================="
