SetupFactory安装前卸载旧版本

在Install Actions中的On Startup中加入代码：

--首先卸载系统中已安装的版本
regBasePath = "Software\\"..SessionVar.Expand("%ProductName%");
if (Registry.DoesKeyExist(HKEY_LOCAL_MACHINE, regBasePath)) then
	Dialog.Message("已存在旧版本", "已存在旧版本，请先卸载旧版本再安装。", MB_OK, MB_ICONEXCLAMATION);
	Uninstaller = Registry.GetValue(HKEY_LOCAL_MACHINE, regBasePath, "Uninstaller", true);
	UninstallData = Registry.GetValue(HKEY_LOCAL_MACHINE, regBasePath, "UninstallData", true);
	Shell.Execute(Uninstaller, "", UninstallData, "");
	Application.Exit();
end

在Install Actions中的On Post Install中加入代码：

--创建卸载信息，方便下次重安装时卸载
regBasePath = "Software\\"..SessionVar.Expand("%ProductName%");
Registry.CreateKey(HKEY_LOCAL_MACHINE, regBasePath);
Registry.SetValue(HKEY_LOCAL_MACHINE, regBasePath, "Uninstaller", SessionVar.Expand("%AppFolder%\\uninstall.exe"), REG_SZ);
Registry.SetValue(HKEY_LOCAL_MACHINE, regBasePath, "UninstallData", SessionVar.Expand("\"/U:%AppFolder%\\Uninstall\\uninstall.xml\""), REG_SZ);
Registry.SetValue(HKEY_LOCAL_MACHINE, regBasePath, "Version", SessionVar.Expand("%ProductVer%"), REG_SZ);

在Uninstall Actions中的On Post Uninstall中加入代码：

--删除注册表信息
regBasePath = "Software\\"..SessionVar.Expand("%ProductName%");
if (Registry.DoesKeyExist(HKEY_LOCAL_MACHINE, regBasePath)) then
	Registry.DeleteKey(HKEY_LOCAL_MACHINE, regBasePath);
end