Bitmap与Byte、Drawable之间的转换

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 转换 drawable
Bitmap bitmap = new Bitmap(...);

Drawable drawable = new BitmapDrawable(bitmap);
//Drawable drawable = new FastBitmapDrawable(bitmap);
4）Drawable to 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);
Drawable d = ImagesList.get(0);

Bitmap bitmap = ((BitmapDrawable)d).getBitmap();

android在处理一写图片资源的时候，会进行一些类型的转换，现在有空整理一下，以便于以后随时可用

1、drawable---->bitmap

View Code

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