Android Drawable、Bitmap、byte[]之间的转换

Drawable –> Bitmap

Bitmap drawable2Bitmap(Drawable drawable) {  
        if (drawable instanceof BitmapDrawable) {  
            return ((BitmapDrawable) drawable).getBitmap();  
        } else if (drawable instanceof NinePatchDrawable) {  
            Bitmap bitmap = Bitmap  
                    .createBitmap(  
                            drawable.getIntrinsicWidth(),  
                            drawable.getIntrinsicHeight(),  
                            drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888  
                                    : Bitmap.Config.RGB_565);  
            Canvas canvas = new Canvas(bitmap);  
            drawable.setBounds(0, 0, drawable.getIntrinsicWidth(),  
                    drawable.getIntrinsicHeight());  
            drawable.draw(canvas);  
            return bitmap;  
        } else {  
            return null;  
        }  
    }  

    Bitmap drawable2Bitmap(Drawable drawable) {
        if (drawable instanceof BitmapDrawable) {
            return ((BitmapDrawable) drawable).getBitmap();
        } else if (drawable instanceof NinePatchDrawable) {
            Bitmap bitmap = Bitmap
                    .createBitmap(
                            drawable.getIntrinsicWidth(),
                            drawable.getIntrinsicHeight(),
                            drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
                                    : Bitmap.Config.RGB_565);
            Canvas canvas = new Canvas(bitmap);
            drawable.setBounds(0, 0, drawable.getIntrinsicWidth(),
                    drawable.getIntrinsicHeight());
            drawable.draw(canvas);
            return bitmap;
        } else {
            return null;
        }
    }

从资源中获取的Drawable –> Bitmap

Resources res = getResources();  
Bitmap bmp = BitmapFactory.decodeResource(res, R.drawable.pic);  
    Resources res = getResources();
    Bitmap bmp = BitmapFactory.decodeResource(res, R.drawable.pic);

Bitmap –> Drawable

Drawable bitmap2Drawable(Bitmap bitmap) {  
        return new BitmapDrawable(bitmap);  
    }  

    Drawable bitmap2Drawable(Bitmap bitmap) {
        return new BitmapDrawable(bitmap);
    }

Bitmap –> byte[]

byte[] Bitmap2Bytes(Bitmap bm) {  
        ByteArrayOutputStream baos = new ByteArrayOutputStream();  
        bm.compress(Bitmap.CompressFormat.PNG, 100, baos);  
        return baos.toByteArray();  
    }  

    byte[] Bitmap2Bytes(Bitmap bm) {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        bm.compress(Bitmap.CompressFormat.PNG, 100, baos);
        return baos.toByteArray();
    }

byte[] –> Bitmap

Bitmap Bytes2Bimap(byte[] b) {  
        if (b.length != 0) {  
            return BitmapFactory.decodeByteArray(b, 0, b.length);  
        } else {  
            return null;  
        }  
    }