inno-setup - 如何检测旧安装并提供删除？

Question

我如何检测用户是否已经安装了软件，如果是，如何提供删除旧版本的可能性？

我写了几行来检查。现在这样正确吗？如果这是正确的，那么如何让用户选择是继续安装还是卸载旧版本？

#define UNINSTKEY "Software\Microsoft\Windows\CurrentVersion\Uninstall\setupname_is1"

var
  uninstallPath: string;

function InitializeSetup: Boolean;
begin
  if (RegQueryStringValue(HKLM,'{#UNINSTKEY}','UninstallString',uninstallPath)) and
     (uninstallPath <> '') and (fileexists(uninstallPath)) then
  begin
    Result :=
      (MsgBox(CustomMessage('NotVerifiedVersionFound'), mbConfirmation,
              MB_YESNO or MB_DEFBUTTON2) = IDYES);
  end;
  { ... }
end;

Answer 1

您可以使用最初发布在此处的 Craig McQueen 的解决方案：InnoSetup：如何自动卸载以前安装的版本？

function GetUninstallString: string;
var
  sUnInstPath: string;
  sUnInstallString: String;
begin
  Result := '';
  sUnInstPath := ExpandConstant('Software\Microsoft\Windows\CurrentVersion\Uninstall\{{A227028A-40D7-4695-8BA9-41DF6A3895C7}_is1'); { Your App GUID/ID }
  sUnInstallString := '';
  if not RegQueryStringValue(HKLM, sUnInstPath, 'UninstallString', sUnInstallString) then
    RegQueryStringValue(HKCU, sUnInstPath, 'UninstallString', sUnInstallString);
  Result := sUnInstallString;
end;

function IsUpgrade: Boolean;
begin
  Result := (GetUninstallString() <> '');
end;

function InitializeSetup: Boolean;
var
  V: Integer;
  iResultCode: Integer;
  sUnInstallString: string;
begin
  Result := True; { in case when no previous version is found }
  if RegValueExists(HKEY_LOCAL_MACHINE,'Software\Microsoft\Windows\CurrentVersion\Uninstall\{A227028A-40D7-4695-8BA9-41DF6A3895C7}_is1', 'UninstallString') then  { Your App GUID/ID }
  begin
    V := MsgBox(ExpandConstant('Hey! An old version of app was detected. Do you want to uninstall it?'), mbInformation, MB_YESNO); { Custom Message if App installed }
    if V = IDYES then
    begin
      sUnInstallString := GetUninstallString();
      sUnInstallString :=  RemoveQuotes(sUnInstallString);
      Exec(ExpandConstant(sUnInstallString), '', '', SW_SHOW, ewWaitUntilTerminated, iResultCode);
      Result := True; { if you want to proceed after uninstall }
      { Exit; //if you want to quit after uninstall }
    end
    else
      Result := False; { when older version present and not uninstalled }
  end;
end;

Answer 2

对于任何感兴趣的人，我为 Inno Setup 6 和更新版本编写了一个小 DLL，它提供了检测是否安装了应用程序并根据您自己的标准自动卸载以前安装的版本的能力。

https://github.com/Bill-Stewart/UninsIS

使用 DLL，您可以仅在降级时、仅在升级时或任一时自动卸载。