android----Bitmap / Drawable / byte[] 之间相互转化

 

1.  Bitmap 转化为 byte
ByteArrayOutputStream out = new ByteArrayOutputStream();bitmap.compress(Bitmap.CompressFormat.PNG, 100, out);byte[] array= out.toByteArray();

2. byte转化为bitmap
final ContentResolver contentResolver = context.getContentResolver();final PackageManager manager = context.getPackageManager();final Cursor c = contentResolver.query(uri, null, null, null, null);final int icon3DIndex = c.getColumnIndexOrThrow(ColumnName);byte[] data = c.getBlob(icon3DIndex);Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);

3. bitmap转化为Drawable
Drawable drawable = new FastBitmapDrawable(bitmap);... 

4. Drawable转化为bitmap
 a. BitmapDrawable, FastBitmapDrawable直接用getBitmap
 b. 其他类型的Drawable用Canvas画到一个bitmap上
     Canvas canvas = new Canvas(bitmap) drawable.draw(canvas);