Question

我使用install4j作为安装程序。我已经安装了我的应用程序，当我再次执行application_installer.exe来安装我的应用程序时，它会要求更新/创建新安装。但是如果已经安装了相同版本的应用程序，我想退出。我怎样才能在install4j安装程序中执行此操作？

Answer 1

您可以使用以下脚本在安装程序的“启动”节点中添加“运行脚本”操作：

// The value returned by context.getInstallationDirectory() will be the last 
// installation directory if the user has already installed the application
ApplicationRegistry.ApplicationInfo applicationInfo =
   ApplicationRegistry.getApplicationInfoByDir(
     context.getInstallationDirectory()
);

if (applicationInfo == null) {
    // The application has never been installed before
    return true;
}

// The version of this installer is contained in a system installer variable
String myVersion = (String)context.getVariable("sys.version");
if (applicationInfo.getVersion().equals(myVersion)) {
    // In that case the current version is already installed.
    Util.showErrorMessage("The current version is already installed" + 
        " in this directory");
    // By returning "false", the action will fail and the installer will quit.
    // Note that you have to set the "Failure strategy" property of your
    // "Run script" action to "Quit on error", otherwise the installer will
    // continue.
    return false;
} else {
    return true;
}

这是代码编辑器代码库中的示例脚本。

如何在已安装应用程序时取消更新/创建新安装

1 个答案: