Install4j - 升级时如何获取当前版本

Question

任何人都知道如何确定安装了install4j的应用程序的当前安装版本。 想法是根据已安装的版本找出安装的内容并控制是否可以升级。

谢谢

Answer 1

您可以使用ApplicationRegistry API用于此目的。以下是一个示例代码片段，可用于“启动”节点中的“运行脚本”操作，以防止当前版本已安装时的安装：

// 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; 
}