Android:Bitmap->Drawble->Byte[]

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：

 

1、Drawable → Bitmap

Java代码  



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;  

}  

 

2、从资源中获取Bitmap

 

Java代码  



Resources res=getResources();  

  

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

 

3、Bitmap → byte[]

 

Java代码  



private byte[] Bitmap2Bytes(Bitmap bm){  

    ByteArrayOutputStream baos = new ByteArrayOutputStream();    

    bm.compress(Bitmap.CompressFormat.PNG, 100, baos);    

    return baos.toByteArray();  

   }  

 

4、 byte[] → Bitmap

Java代码  



private Bitmap Bytes2Bimap(byte[] b){  

            if(b.length!=0){  

                return BitmapFactory.decodeByteArray(b, 0, b.length);  

            }  

            else {  

                return null;  

            }  

      }  

 

转换Bitmap to Drawable

 

Java代码  



BitmapDrawable bitmapDrawable = (BitmapDrawable)bitmap;     

Drawable drawable = (Drawable)bitmapDrawable;     

    

    

Bitmap bitmap = new Bitmap (...);     

Drawable drawable = new BitmapDrawable(bitmap);  

 ///////BitmapDrawable bitmapDrawable = (BitmapDrawable)bitmap;这一句应该改成BitmapDrawable bd = new BitmapDrawable(bitmap);////////

 

转换Drawable to Bitmap

 

Java代码  



Drawable d = ImagesList.get(0);  

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