koobas.hobune.stream
Access raw AssetBundle data using UnityWebRequest?
Following Unity's advice, starting Unity 5.3, it is strongly recommended to use UnityWebRequest -rather than WWW.LoadFromCacheOrDownload- to download AssetBundles from a server. However, we also need to store the downloaded bundles locally (via Application.persistentDataPath)... but how??
WWW.LoadFromCacheOrDownload provides you with a byte[] that could be saved/loaded. Unfortunately, accessing the data field in DownloadHandlerAssetBundle is not allowed and triggers an exception. Is there any way to access/save the downloaded data using UnityWebRequest? Or are we forced to go back and use WWW.LoadFromCacheOrDownload instead?
PS - We are aware of the Caching functionality, but we want to store it locally.
Have you found any solution for this? I am having the same problem right now and i can't find anything working...
I'm trying to get answers to this. Am aware of the caching class, problem is , where do i actually retreive the cached data? I can't write it locally using www.downloadHandler.data - I get error "NotSupportedException: Raw data access is not supported for asset bundles".
DownloadHandlerAssetBundle cannot access .data or .GetData, the content is null.
Hi, this seems to work:
string url = "http://myserver.com/myassetBundle";
UnityWebRequest www = UnityWebRequest.Get(url);
yield return www.Send();
string filePath = Path.Combine(Application.persistentDataPath, "myassetBundle");
File.WriteAllBytes(filePath, www.downloadHandler.data);
AssetBundle bundle = AssetBundle.LoadFromFile(filePath);
It is a raw code, you need to write validations...
it doesn't work！it throw error like this: NotSupportedException: Raw data access is not supported for asset bundles
If you're using DownloadHandlerAssetBundle, your AssetBundle data will probably be cached locally by Unity automatically. Since you want to access the raw binary data, I assume that you're implementing your own AssetBundle cache system and want to bypass Unity's implementation.
Then you will have to write your own DownloadHandlerScript like this:
class CustomAssetBundleDownloadHandler : DownloadHandlerScript
{
private string _targetFilePath;
private Stream _fileStream;
public CustomAssetBundleDownloadHandler(string targetFilePath)
: base(new byte[4096]) // use pre-allocated buffer for better performance
{
_targetFilePath = targetFilePath;
}
protected override bool ReceiveData(byte[] data, int dataLength)
{
// create or open target file
if (_fileStream == null)
{
_fileStream = File.OpenWrite(_targetFilePath);
}
// write data to file
_fileStream.Write(data, 0, dataLength);
return true;
}
protected override void CompleteContent()
{
// close and save
_fileStream.Close();
}
}
When you need to download a file, just create a new CustomAssetBundleDownloadHandler(pathToFile), assign it to the UnityWebRequest object as its download handler, and data will be saved to the target file.
so...is it WWW www = UnityWebRequest.GetAssetBundle (new CustomAssetBundleDownloadHandler (bundleURL), hashString, 0); ??
but bundleURL should be where the file should be written to right?
I did it like this
UnityWebRequest www = UnityWebRequest.Get (bundleURL + ".manifest");
// create empty hash string
Hash128 hashString = (default(Hash128));
if (www.downloadHandler.text.Contains ("$$anonymous$$anifestFileVersion")) {
var hashRow = www.downloadHandler.text.ToString ().Split ("\n".ToCharArray ()) [5];
hashString = Hash128.Parse (hashRow.Split (':') [1].Trim ());
if (hashString.isValid == true) {
if (Caching.IsVersionCached (bundleURL, hashString) == true) {
Debug.Log ("Bundle with this hash is already cached!... " + hashString);
} else {
string writepath = Application.persistentDataPath + "/" + hashString;
www.downloadHandler = new CustomAssetBundleDownloadHandler (writepath);
Debug.Log ("No cached version founded for this hash.." + hashString);
}
I get error InvalidOperationException: UnityWebRequest has already been sent; cannot modify the download handler
i think you can download ab as a file and save it on local then load it OK?
