Inno Setup - 卸载程序时从PATH环境变量中删除路径 [英] Inno Setup - Remove path from PATH environment variable while uninstalling a program

问题描述

我写了一个Inno Setup脚本，它安装一个程序，并使用安装程序的目录更新
PATH 环境变量。

I wrote an Inno Setup script which install a program and update the PATH environment variable with the directory in which the program in installed.

我想更新 PATH 环境变量，以恢复其以前的安装状态。

I want to update the PATH environment variable, to restore its previous installation status.

安装程序运行时，用户选择安装路径。

The installation path is chosen by the user while the installer is running.

这是脚本，使用如何在运行Inno安装程序安装程序时修改PATH环境变量？

[Setup]
AppName=Pandoc_x64
AppVersion=1.16.0.2
AppPublisher=Hitachi Systems CBT
DefaultDirName={pf64}\pandoc
UninstallDisplayName=Pandoc_x64
DisableDirPage=no
UninstallFilesDir={app}\uninstall

[Files]
Source: "pandoc.exe"; DestDir: "{app}";
Source: "pandoc-citeproc.exe"; DestDir: "{app}";


[Setup]
ChangesEnvironment=yes

[Registry]
Root: HKLM; Subkey: "SYSTEM\CurrentControlSet\Control\Session Manager\Environment"; \
    ValueType: expandsz; ValueName: "PATH"; ValueData: "{olddata};{app}"; \
    Check: NeedsAddPath('{app}')
Root: HKLM; Subkey: "SYSTEM\CurrentControlSet\Control\Session Manager\Environment";  ValueName: "PATH"; ValueData: "{app}"; Flags: uninsdeletevalue

[Code]
function NeedsAddPath(Param: string): boolean;
var
  OrigPath: string;
begin
  if not RegQueryStringValue(HKEY_LOCAL_MACHINE,
    'SYSTEM\CurrentControlSet\Control\Session Manager\Environment',
    'Path', OrigPath)
  then begin
    Result := True;
    exit;
  end;
  // look for the path with leading and trailing semicolon
  // Pos() returns 0 if not found
  Result := Pos(';' + Param + ';', ';' + OrigPath + ';') = 0;
end;

查看代码，可以注意以下说明：

Taking a look to the code, it's possible to note the following instruction:

Root: HKLM; Subkey: "SYSTEM\CurrentControlSet\Control\Session Manager\Environment";  ValueName: "PATH"; ValueData: "{app}"; Flags: uninsdeletevalue

我用这个指令，在我看来，适用于我的例子，一个href =https://stackoverflow.com/q/26762668/850848> Inno安装程序。如何卸载注册表值？

I used that instruction, adapted (in my opinion) for the my example, reading Inno Setup. How to uninstall registry value?

使用 uninsdeletevalue 应该在程序中删除该值被卸载，事实上，当我运行卸载程序时，整个 PATH 变量被删除，但是我需要恢复 PATH 环境变量为先前的安装值。
我认为在运行安装程序之前可能会读取它的价值，但我不知道如何在卸载阶段使用它。

The use of uninsdeletevalue should be delete the value when the program is uninstalled, and in fact, when I run the uninstaller, the entire PATH variable is deleted, but I need to restore the PATH environment variable to the previous installation value. I think it's possible reading its value before run the installer, but I don't have any idea to how use it in the uninstall phase.

有人可以帮助我一个代码示例？

Can someone help me with a code example?

推荐答案

您不能让Inno Setup记住安装时的价值，并使用 [注册表] 部分条目。

You cannot have Inno Setup remember the value on installation and restore it, when uninstalling using [Registry] section entry only.

虽然你可以编写代码，但这并不好，因为 PATH 可能在安装后发生更改，您将丢弃任何此类更改。

While you can code it, it's not good approach anyway as the PATH likely changes after the installation and you will discard any such changes.

您必须搜索 PATH 为您的路径，只删除路径。

You have to search the PATH for your path and remove the path only.

const
  EnvironmentKey = 'SYSTEM\CurrentControlSet\Control\Session Manager\Environment';

procedure RemovePath(Path: string);
var
  Paths: string;
  P: Integer;
begin
  if not RegQueryStringValue(HKEY_LOCAL_MACHINE, EnvironmentKey, 'Path', Paths) then
  begin
    Log('PATH not found');
  end
    else
  begin
    Log(Format('PATH is [%s]', [Paths]));

    P := Pos(';' + Uppercase(Path) + ';', ';' + Uppercase(Paths) + ';');
    if P = 0 then
    begin
      Log(Format('Path [%s] not found in PATH', [Path]));
    end
      else
    begin
      Delete(Paths, P - 1, Length(Path) + 1);
      Log(Format('Path [%s] removed from PATH => [%s]', [Path, Paths]));

      if RegWriteStringValue(HKEY_LOCAL_MACHINE, EnvironmentKey, 'Path', Paths) then
      begin
        Log('PATH written');
      end
        else
      begin
        Log('Error writing PATH');
      end;
    end;
  end;
end;

procedure CurUninstallStepChanged(CurUninstallStep: TUninstallStep);
begin
  if CurUninstallStep = usUninstall then
  begin
    RemovePath(ExpandConstant('{app}'));
  end;
end;

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