drawable转mitmap 以及图片base64编码

 static Bitmap drawableToBitmap(Drawable drawable) // drawable 转换成bitmap
    {
        int width = drawable.getIntrinsicWidth();// 取drawable的长宽
        int height = drawable.getIntrinsicHeight();
        Bitmap.Config config = drawable.getOpacity() != PixelFormat.OPAQUE ?Bitmap.Config.ARGB_8888:Bitmap.Config.RGB_565;// 取drawable的颜色格式
        Bitmap bitmap = Bitmap.createBitmap(width, height, config);// 建立对应bitmap
        Canvas canvas = new Canvas(bitmap);// 建立对应bitmap的画布
        drawable.setBounds(0, 0, width, height);
        drawable.draw(canvas);// 把drawable内容画到画布中
        return bitmap;
    }

调用代码，getDrawable过期了，但是还可以用，替换的方法暂未发现

 Bitmap bitmap = drawableToBitmap(this.getResources().getDrawable(R.drawable.ic_launcher));

2.图片转base64

 public String Bitmap2StrByBase64(Bitmap bit){
        ByteArrayOutputStream bos=new ByteArrayOutputStream();
        bit.compress(Bitmap.CompressFormat.JPEG, 40, bos);//参数100表示不压缩
        byte[] bytes=bos.toByteArray();
        return Base64.encodeToString(bytes, Base64.DEFAULT);
    }

1.Drawable—>Bitmap

Resources res=getResources();

Bitmap bmp=BitmapFactory.decodeResource(res, R.drawable.sample_0);
Resources res=getResources();
private byte[] Bitmap2Bytes(Bitmap bm){

2.Bitmap---->Drawable

Drawable drawable =new BitmapDrawable(bmp);

3、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、从资源中获取Bitmap

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

5、Bitmap → byte[]

ByteArrayOutputStream baos = new ByteArrayOutputStream();

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

return baos.toByteArray();   }

6、 byte[] → Bitmap

private Bitmap Bytes2Bimap(byte[] b){

if(b.length!=0){

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

}

else {

return null;

}

}