The relationship between mobile screen size and iOS development coordinates

physical size: Refers to the size of the diagonal screen, usually in inches (inch) to indicate. Resolution: Refers to the number of pixel points that are contained within the unit length. For example, on a screen with a resolution of 1024x768, where each horizontal line contains 1024 pixels, there are 768 lines, that is, the number of scanned columns is 1024 columns, and the number of rows is 768 rows. The units that describe the resolution are dpi (dots per inch), LPI (lines per inch), and PPI (pixels per inch). PPI calculation formula:      (X: length pixels; Y: width pixels; Z: screen physical size)             share a PPI online calculator: Entrance For example Xiaomi Phone 2 PPI is calculated as: =        = 2px

The relationship between mobile screen size and iOS development coordinates