Drawable to byte[] | 易学教程

问题

I have an image from the web in an ImageView. It is very small (a favicon) and I\'d like to store it in my SQLite database. I can get a Drawable from mImageView.getDrawable() but then I don\'t know what to do next. I don\'t fully understand the Drawable class in Android.

I know I can get a byte array from a Bitmap like:

Bitmap defaultIcon = BitmapFactory.decodeStream(in);

ByteArrayOutputStream stream = new ByteArrayOutputStream();
defaultIcon.compress(Bitmap.CompressFormat.JPEG, 100, stream);

byte[] bitmapdata = stream.toByteArray();

But how do I get a byte array from a Drawable?

回答1:

Drawable d; // the drawable (Captain Obvious, to the rescue!!!)
Bitmap bitmap = ((BitmapDrawable)d).getBitmap();
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream);
byte[] bitmapdata = stream.toByteArray();

回答2:

Thanks all and this solved my problem.

Resources res = getResources();
Drawable drawable = res.getDrawable(R.drawable.my_pic);
Bitmap bitmap = ((BitmapDrawable)drawable).getBitmap();
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream);
byte[] bitMapData = stream.toByteArray();

回答3:

Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.tester);
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream);
byte[] bitMapData = stream.toByteArray();

回答4:

If Drawable is an BitmapDrawable you can try this one.

long getSizeInBytes(Drawable drawable) {
    if (drawable == null)
        return 0;

    Bitmap bitmap = ((BitmapDrawable) drawable).getBitmap();
    return bitmap.getRowBytes() * bitmap.getHeight();
}

Bitmap.getRowBytes() returns the number of bytes between rows in the bitmap's pixels.

For more refer this project: LazyList

回答5:

File myFile = new File(selectedImagePath);

byte [] mybytearray  = new byte [filelenghth];

BufferedInputStream bis1 = new BufferedInputStream(new FileInputStream(myFile));

bis1.read(mybytearray,0,mybytearray.length);

now the image is stored in the bytearray..

来源：https://stackoverflow.com/questions/4435806/drawable-to-byte

标签

android

database

drawable

android-bitmap