如何访问在“项目”>“构建设置”>“其他Swift标志”中定义的值？

Question

I have a value in Other Swift Flags -DSERVER_IP=${SERVER_IP} linked to a Build Phase > Run Script: export SERVER_IP='ipconfig getifaddr en0'

How do I access the value of SERVER_IP from a ViewController or a swift file and use it to populate a variable in swift? Something like let currentIP = SERVER_IP

Answer 1

Build settings use environment variables that exist at the time the build start, which is before your build phase runs. Due to this, SERVER_IP will be empty while Xcode is doing its the build phase (exported variables are not available to other build phases).

There is a workaround, though. You can add a new Swift file to the project, let's call it generated-stuff.swift , and have the run script output the information there:

echo 'let SERVER_IP="'`ipconfig getifaddr en0`'"' > MyProject/generated-stuff.swift

The above will generate a file like with the following contents:

let SERVER_IP="1.2.3.4"

You'll then be able to use the variable in your project.