When i develop an iOS app, i add a UITextField in the app UI programmatically. And i also add some constraints to the UITextField object in swift source code to […]
When i upgrade my Xcode to version 10.3 and build my iOS project, i meet an error message like this Failed to find or create execution context for description ‘<IBCocoaTouchPlatformToolDescription: […]
When i add swift constraints to button programmatically in source code, i meet an error message like this. [LayoutConstraints] Unable to simultaneously satisfy constraints. Probably at least one of the […]
Swift optional variable is a variable which can has nil ( same to null ) value. And you do not need to initialize an optional variable before use it. If […]
