有时候我们需要直接获取sd卡上的apk文件的包名、版本等信息
PackageManager pm = this.getPackageManager();
PackageInfo info = pm.getPackageArchiveInfo(task.filePath,
PackageManager.GET_ACTIVITIES);
if (info != null) {
String packageName = info.packageName;
int versionCode = info.versionCode;
}