Android Bitmap的基本知识（从资源文件中获取以及与S

2）、
Resources r = this.getContext().getResources();
Inputstream is = r.openRawResource(R.drawable.my_background_image);
BitmapDrawable bmpDraw = new BitmapDrawable(is);
Bitmap bmp = bmpDraw.getBitmap();

3）、
Bitmap bmp=BitmapFactory.decodeResource(r, R.drawable.icon);
Bitmap newb = Bitmap.createBitmap( 300, 300, Config.ARGB_8888 );

4）、
InputStream is = getResources().openRawResource(R.drawable.icon);
Bitmap mBitmap = BitmapFactory.decodeStream(is);

    }  
  
    /**  
     * string转成bitmap  
     *   
     * @param st  
     */  
    public static Bitmap convertStringToIcon(String st)  
    {  
        // OutputStream out;  
        Bitmap bitmap = null;  
        try  
        {  
            // out = new FileOutputStream("/sdcard/aa.jpg");  
            byte[] bitmapArray;  
            bitmapArray = Base64.decode(st, Base64.DEFAULT);  
            bitmap =  
                    BitmapFactory.decodeByteArray(bitmapArray, 0,  
                            bitmapArray.length);  
            //  100, out);  
            return bitmap;  
        }  
        catch (Exception e)  
        {  
            return null;  
        }  
    }  

2)、Drawable → Bitmap
public static Bitmap drawableToBitmap(Drawable drawable) {
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);
//canvas.setBitmap(bitmap);
drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());
drawable.draw(canvas);
return bitmap;
}

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