如果在Inno Setup中更新了安装，则在ssPostInstall步骤中排除“代码"部分的一部分 [英] Excludes part of Code section in ssPostInstall step if installation is update in Inno Setup

问题描述

我尝试同时使用同一安装程序(全新安装和更新).

I try to use same installer for both (fresh installation and update).

• 因此，如果用户首次尝试安装我的应用程序，它将作为前提条件运行包括MySQL安装程序在内的完整安装，并且 [Code] 中的MySQL安装部分将正常执行.
• 但是，如果用户已经安装了我的应用程序，并且安装程序是较新的版本(更新)，则不应执行 [Code] 中的MySQL安装部分.

• so if user try to install my application for first time it will run the full installation included MySQL installer as prerequisites, and the part of MySQL installation within [Code] will execute normally.
• but, if user already installed my application, and the installer is newer version (update), the part of MySQL installation within [Code] shouldn't be execute.

那么，如果安装只是在更新，那么如何为这部分代码(MySQL安装)实现异常功能?

So, how to implement exception function for this part of code (MySQL installation) if the installation is just updating?

[Code]

procedure CurStepChanged(CurStep: TSetupStep);
{ ... }
begin
  if CurStep = ssPostInstall then
  begin
    { fresh installation code }
  end;
end;

推荐答案

您可以在我对
的回答中使用 IsUpgrade 函数 Inno Setup能否对新安装和更新做出不同反应?:

尽管它依赖于在 ssPostInstall 时已经存在的卸载"注册表项的存在，但是您必须缓存其值.

Though as it relies on a presence of "Uninstall" registry key, which already exists at the time of ssPostInstall, you have to cache its value.

var
  IsUpgradeCached: Boolean;

function InitializeSetup(): Boolean;
begin
  IsUpgradeCached := IsUpgrade;
  Result := True;
end;

procedure CurStepChanged(CurStep: TSetupStep);
{ ... }
begin
  if (CurStep = ssPostInstall) and (not IsUpgradeCached) then
  begin
    { fresh installation code }
  end;
end;

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