云在千峰

Android系统中Drawable Bitmap 和byte[] 直接的转换.

在BitmapFactory中有多种decodeBitmap的方法,可以从文件、资源、二进制流、输入流等多种方法获取Bitmap。详细情况可以参考BitmapFactory的java doc。

	/**
	 * Convert Drawable to Bitmap
	 * @param drawable
	 * @return
	 */
	public Bitmap drawableToBitmap(Drawable drawable) {
		Bitmap bitmap = Bitmap.createBitmap(
			drawable.getIntrinsicWidth(),
			drawable.getIntrinsicHeight(),
			drawable.getOpacity() == PixelFormat.OPAQUE ?
				Bitmap.Config.RGB_565: Bitmap.Config.ARGB_8888);
		Canvas canvas = new Canvas(bitmap);
		drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), 
				drawable.getIntrinsicHeight());
		drawable.draw(canvas);
		return bitmap;
	}
	/**
	 * Bitmap to byte array.
	 * @param bitmap
	 * @return
	 */
	public byte[] bitmapToBytes(Bitmap bitmap) {
		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		bitmap.compress(Bitmap.CompressFormat.PNG/*OR JPEG*/, 100, baos);
		return baos.toByteArray();
	}
	
	
	/**
	 * Use BitmapFactory decodeXXX method 
	 * there are a lot of decode method . see the java doc
	 * @return 
	 */
	public Bitmap getBitmap() {
		return BitmapFactory.decodeFile("pic file path");
	}