AssetBundle.LoadFromStreamAsync

Parameters

Returns

AssetBundleCreateRequest Asynchronous create request for an AssetBundle. Use assetBundle property to get an AssetBundle once it is loaded.

Description

Asynchronously loads an AssetBundle from a managed Stream.

The function supports bundles of any compression type. lzma compressed data is decompressed to memory, while uncompressed and chunk-compressed bundles are read directly from the Stream.

Unlike LoadFromStream, this function is asynchronous.

Unlike LoadFromFileAsync, the data for the AssetBundle is supplied by a managed Stream object.

The following are restrictions on a Stream object to optimize AssetBundle data loading:
1. The AssetBundle data must start at stream position zero.
2. Unity sets the seek position to zero before it loads the AssetBundle data.
3. Unity assumes the read position in the stream is not altered by any other process. This allows the Unity process to read from the stream without having to call Seek() before every read.
4. stream.CanRead must return true.
5. stream.CanSeek must return true.
6. It must be accessible from threads different to the main thread. Seek() and Read() can be called from any Unity native thread.

Do not dispose the Stream object while loading the AssetBundle or any assets from the bundle. Its lifetime should be longer than the AssetBundle. This means you dispose the Stream object after calling AssetBundle.Unload.

using UnityEngine;
using System.Collections;
using System.IO;
using System;

public class LoadFromFileAsyncExample : MonoBehaviour
{
    IEnumerator Start()
    {
        var fileStream = new FileStream(Application.streamingAssetsPath, FileMode.Open, FileAccess.Read);
        var bundleLoadRequest = AssetBundle.LoadFromStreamAsync(fileStream);
        yield return bundleLoadRequest;

        var myLoadedAssetBundle = bundleLoadRequest.assetBundle;
        if (myLoadedAssetBundle == null)
        {
            Debug.Log("Failed to load AssetBundle!");
            yield break;
        }

        var assetLoadRequest = myLoadedAssetBundle.LoadAssetAsync<GameObject>("MyObject");
        yield return assetLoadRequest;

        GameObject prefab = assetLoadRequest.asset as GameObject;
        Instantiate(prefab);

        myLoadedAssetBundle.Unload(false);
    }
}

See Also: AssetBundle, LoadFromStream LoadFromFileAsync.