Load an image from assets folder

Question

I am trying to load an image from the asset folder and then set it to an ImageView. I know it's much better if I use the R.id.* for this, but the premise is I don't know the id of the image. Basically, I'm trying to dynamically load the image via its filename.

For example, I randomly retrieve an element in the database representing let's say a 'cow', now what my application would do is to display an image of a 'cow' via the ImageView. This is also true for all element in the database. (The assumption is, for every element there is an equivalent image)

How do I load the image from the asset folder?

Answer 1

Checkout this code . IN this tutorial you can find how to load image from asset folder.

// load image

try 
{
    // get input stream
    InputStream ims = getAssets().open("avatar.jpg");
    // load image as Drawable
    Drawable d = Drawable.createFromStream(ims, null);
    // set image to ImageView
    mImage.setImageDrawable(d);
    ims .close();
}
catch(IOException ex) 
{
    return;
}

Answer 2

Here you are,

  public Bitmap getBitmapFromAssets(String fileName) throws IOException {
    AssetManager assetManager = getAssets();

    InputStream istr = assetManager.open(fileName);
    Bitmap bitmap = BitmapFactory.decodeStream(istr);
    istr.close();

    return bitmap;
}

Answer 3

If you know the filename in the code, calling this won't be a problem:

ImageView iw= (ImageView)findViewById(R.id.imageView1);  
int resID = getResources().getIdentifier(drawableName, "drawable",  getPackageName());
iw.setImageResource(resID);

Your filename will be the same name as drawableName so you won't have to deal with assets.

Answer 4

Some of these answers may answer the question but I never liked any of them so I ended up writing this, it my help the community.

Get Bitmap from assets:

public Bitmap loadBitmapFromAssets(Context context, String path)
{
    InputStream stream = null;
    try
    {
        stream = context.getAssets().open(path);
        return BitmapFactory.decodeStream(stream);
    }
    catch (Exception ignored) {} finally
    {
        try
        {
            if(stream != null)
            {
                stream.close();
            }
        } catch (Exception ignored) {}
    }
    return null;
}

Get Drawable from assets:

public Drawable loadDrawableFromAssets(Context context, String path)
{
    InputStream stream = null;
    try
    {
        stream = context.getAssets().open(path);
        return Drawable.createFromStream(stream, null);
    }
    catch (Exception ignored) {} finally
    {
        try
        {
            if(stream != null)
            {
                stream.close();
            }
        } catch (Exception ignored) {}
    }
    return null;
}

Answer 5

public static Bitmap getImageFromAssetsFile(Context mContext, String fileName) {
        Bitmap image = null;
        AssetManager am = mContext.getResources().getAssets();
        try {
            InputStream is = am.open(fileName);
            image = BitmapFactory.decodeStream(is);
            is.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return image;
    }

Answer 6

According to Android Developer Documentation loading with bitmap can degrade app performane.Here's a link! So doc suggest to use Glide library.

If you want to load image from assets folder then using Glide library help you alots easier.

just add dependencies to build.gradle (Module:app) from https://github.com/bumptech/glide

 dependencies {
  implementation 'com.github.bumptech.glide:glide:4.9.0'
  annotationProcessor 'com.github.bumptech.glide:compiler:4.9.0'
}

sample example :

// For a simple view:
@Override public void onCreate(Bundle savedInstanceState) {
  ...
  ImageView imageView = (ImageView) findViewById(R.id.my_image_view);

  Glide.with(this).load("file:///android_asset/img/fruit/cherries.jpg").into(imageView);
}

In case not worked by above method : Replace this object with view object from below code (only if you have Inflate method applied as below in your code).

 LayoutInflater mInflater =  LayoutInflater.from(mContext);
        view  = mInflater.inflate(R.layout.book,parent,false);

Answer 7

This worked in my use case:

AssetManager assetManager = getAssets();
ImageView imageView = (ImageView) findViewById(R.id.imageView);
try (
        //declaration of inputStream in try-with-resources statement will automatically close inputStream
        // ==> no explicit inputStream.close() in additional block finally {...} necessary
        InputStream inputStream = assetManager.open("products/product001.jpg")
) {
    Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
    imageView.setImageBitmap(bitmap);
} catch (IOException ex) {
    //ignored
}

(see also https://javarevisited.blogspot.com/2014/10/right-way-to-close-inputstream-file-resource-in-java.html)

Answer 8

You simply can use this Kotlin extension function where String is referred to fileName

fun String.assetsToBitmap(context: Context): Bitmap? {
    return try {
        val assetManager = context.assets
        val inputStream = assetManager.open(this)
        val bitmap = BitmapFactory.decodeStream(inputStream)
        inputStream.close()
        bitmap
    } catch (e: Exception) {
        e.printStackTrace()
        null
    }
}

Sample usage

val myBitmap = "sample.png".assetsToBitmap(context)

Answer 9

WebView web = (WebView) findViewById(R.id.webView);
web.loadUrl("file:///android_asset/pract_recommend_section1_pic2.png");
web.getSettings().setBuiltInZoomControls(true);