Unity3D. Change global define by code.

GlobalDefineEditor.cs

 private static void AddOneGlobalDefine(BuildTargetGroup group, string newDefine) {
        string define = PlayerSettings.GetScriptingDefineSymbolsForGroup(group);
        if(define == string.Empty) {
            define = newDefine;
        } else {
            define = define + ";" + newDefine;
        }
        PlayerSettings.SetScriptingDefineSymbolsForGroup(BuildTargetGroup.Android, define);
        Debug.Log("Current global define: " + define);
    }

    /// <summary>
    /// Replaces the one globl define to another in target group.
    /// </summary>
    /// <returns>
    /// "-2": one of both given string arguments is empty; 
    /// "-1": can't find parameter beReplaced. Use AddOneGloblDefine() to add a new define.
    /// "0": the parameter replaceBy is allready in current global define list; 
    /// "1": replace done.
    /// </returns>;
    /// <param name="group">Group.</param>
    /// <param name="beRepcased">The defien should be repcased.</param>
    /// <param name="replaceBy">Replace by this string.</param>
    private static int ReplaceOneGlobalDefineBy(BuildTargetGroup group, string beReplaced, string replaceBy) {
        string define = PlayerSettings.GetScriptingDefineSymbolsForGroup(group);
        if(beReplaced == string.Empty || replaceBy == string.Empty) 
        {
            return -2;
        }
        else if(define.Contains(replaceBy)) 
        {
            return -1;
        }
        else if(define == string.Empty || !define.Contains(beReplaced))
        {
            return -0;
        }
        else 
        {
            define = define.Replace(beReplaced, replaceBy);
            PlayerSettings.SetScriptingDefineSymbolsForGroup(BuildTargetGroup.Android, define);
            Debug.Log("Current global define: " + define);
            return 1;
        }
    }

    private static void RemoveOneGlobalDefine(BuildTargetGroup group, string removed) {
        string define = PlayerSettings.GetScriptingDefineSymbolsForGroup(group);
        if(define == string.Empty || removed == string.Empty || !define.Contains(removed)) {
            return;
        } else {
            define = define.Replace(removed,"");
        }

        PlayerSettings.SetScriptingDefineSymbolsForGroup(BuildTargetGroup.Android, define);
        Debug.Log("Current global define: " + define);
    }