Install4j - 升級時如何獲取當前版本

Question

任何人都知道如何確定安裝了install4j的應用程序的當前安裝版本。 想法是根據已安裝的版本找出安裝的內容並控制是否可以升級。

謝謝

Answer 1

您可以使用ApplicationRegistry API用於此目的。以下是一個示例代碼片段，可用於「啓動」節點中的「運行腳本」操作，以防止當前版本已安裝時的安裝：

// 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; 
}