adnroid已安装应用中检测某应用是否安装的代码实例

//检查某个应用是否安装
    public static boolean checkapp(context context, string packagename) {
        if (packagename == null || "".equals(packagename))
            return false;
        try {
            applicationinfo info = context.getpackagemanager()
                    .getapplicationinfo(packagename,
                            packagemanager.get_uninstalled_packages);
            return true;
        } catch (namenotfoundexception e) {
            return false;
        }
    }