安卓手机获取包信息，nativajs

//参数：包名;返回：包信息
getAPPInfo:function(packageName){
if(!plus)return {versionName:null,versionCode:null};
var main = plus.android.runtimeMainActivity();
var packageManager = main.getPackageManager();
var PackageManager = plus.android.importClass(packageManager);
var packageInfo = packageManager.getPackageInfo(packageName,PackageManager.GET_ACTIVITIES);
if(packageInfo){//类对象，获取其类属性值
var versionName = plus.android.getAttribute(packageInfo,"versionName");
var versionCode = plus.android.getAttribute(packageInfo,"versionCode");
return {versionName:versionName,versionCode:versionCode};
}else{
return {versionName:null,versionCode:null};
}
},