PBXProject.FindFileGuidByProjectPath

Находит в проекте файл с указанным путем к проекту.

using UnityEngine;
using UnityEditor;
using System.IO;
using UnityEditor.Callbacks;
using UnityEditor.iOS.Xcode;

public class Sample_FindFileGuidByProjectPath  
{
    [PostProcessBuild]
    public static void OnPostprocessBuild(BuildTarget buildTarget, string pathToBuiltProject)
    {

        // Stop processing if build target is not iOS
        if (buildTarget != BuildTarget.iOS)
            return;

        // Initialize PBXProject
        string projectPath = PBXProject.GetPBXProjectPath(pathToBuiltProject);
        PBXProject pbxProject = new PBXProject();
        pbxProject.ReadFromFile(projectPath);

        // Get the GUID by using a path relative to the Xcode project structure and print it to the Console
        string filePath = "Path/To/ExampleFile.txt";
        string fileGuid = pbxProject.FindFileGuidByProjectPath(filePath);
        Debug.Log("File GUID: " + fileGuid);

        // Apply changes to the pbxproj file
        pbxProject.WriteToFile(projectPath);
    }
}