What causes "执行修改 {serv_name} DisplayName 参数时，返回值为空！" in OdysseusYuan/LKY_OfficeTools?

Ensure cmd.exe is on PATH and not blocked; run elevated.

OdysseusYuan/LKY_OfficeTools · error · Exception

执行修改 {serv_name} DisplayName 参数时，返回值为空！

Error message

执行修改 {serv_name} DisplayName 参数时，返回值为空！

What it means

Thrown in Com_ServiceOS.Config.Modify.DisplayName when the stdout from `sc config ... DisplayName=` via Run.Cmd is null or empty (Com_ServiceOS.cs:421-423). Run.Cmd returns null only from its catch, so this denotes a cmd.exe/redirect infrastructure failure, not an sc error (which still returns text). DisplayName catches the throw, logs it, and returns false (Com_ServiceOS.cs:441-445).

Source

Thrown at LKY_OfficeTools/Common/Com_ServiceOS.cs:423

                        new Log(Ex.ToString());
                        return false;
                    }
                }

                internal static bool DisplayName(string serv_name, string serv_displayname)
                {
                    try
                    {
                        if (Query.IsCreated(serv_name))
                        {
                            //已经创建服务，才进行修改
                            string cmd_modify_displayname = $"sc config \"{serv_name}\" DisplayName=\"{serv_displayname}\"";
                            var modify_result = Com_ExeOS.Run.Cmd(cmd_modify_displayname);

                            //非空判断，若返回值为空，则为假
                            if (string.IsNullOrEmpty(modify_result))
                            {
                                throw new Exception($"执行修改 {serv_name} DisplayName 参数时，返回值为空！");
                            }

                            //判断是否修改 DisplayName 成功
                            if (modify_result.Contains("成功") || modify_result.ToLower().Contains("success"))
                            {
                                return true;
                            }
                            else
                            {
                                throw new Exception($"修改服务 {serv_name} 的 DisplayName 信息为 {serv_displayname} 失败！");
                            }
                        }
                        else
                        {
                            throw new Exception($"尝试修改服务 {serv_name} 的 DisplayName 信息为 {serv_displayname}，但该服务未安装！");
                        }
                    }
                    catch (Exception Ex)

View on GitHub (pinned to 6f9a1bd471)

Solutions

Ensure cmd.exe is on PATH and not blocked; run elevated.
Run `sc config <name> DisplayName=...` directly in a console to confirm sc works.
Inspect the bool return and Lib_AppLog for Run.Cmd's caught exception.
Fix the cmd/redirect environment then retry.

Example fix

// before
bool ok = Com_ServiceOS.Config.Modify.DisplayName(name, display);

// after
if (!Com_ServiceOS.Query.IsCreated(name)) { return false; }
bool ok = Com_ServiceOS.Config.Modify.DisplayName(name, display);

Defensive patterns

Strategy: validation

Validate before calling

if (!Com_ServiceOS.Query.IsCreated(name)) { return false; }
bool ok = Com_ServiceOS.Config.Modify.DisplayName(name, display);

Type guard

static bool ServiceRegistered(string name) => Com_ServiceOS.Query.IsCreated(name);

Prevention

DisplayName swallows the throw and returns false; check the bool return and log.
Ensure cmd.exe is reachable and not blocked by policy.
Run elevated before issuing sc config.
Reproduce `sc config <name> DisplayName=...` in a console when debugging.

When it happens

Trigger: Run.Cmd throws because cmd.exe cannot launch, output redirection fails, or the process is killed before producing stdout.

Common situations: cmd.exe blocked by AppLocker/WDAC on a hardened host; stdio handle exhaustion; antivirus hooking redirected console output.

Related errors

AI-assisted analysis of OdysseusYuan/LKY_OfficeTools@6f9a1bd471 (2026-08-13). Data as JSON: /api/errors/b54f82a70fd83a8b. Report an issue: GitHub.