Android 中 Bitmap 和 Drawable 相互转换的方法

以你之姓@ 2022-06-01 02:59 233阅读 0赞

文章转自：[http://blog.csdn.net/l\_lhc/article/details/50923372][http_blog.csdn.net_l_lhc_article_details_50923372]

# 一、Drawable 转换成 Bitmap #

**方法一**

通过 BitmapFactory 中的 decodeResource 方法，将资源文件中的 R.drawable.ic\_drawable 转化成Bitmap

Resources res = getResources();
    Bitmap    bmp = BitmapFactory.decodeResource(res, R.drawable.ic_drawable);

**方法二**

将 Drable 对象先转化成 BitmapDrawable ，然后调用 getBitmap 方法 获取

Resource res      = gerResource();
    Drawable drawable = res.getDrawable(R.drawable.ic_drawable);//获取drawable
    BitmapDrawable bd = (BitmapDrawable) drawable;
    Bitmap bm         = bd.getBitmap();

**方法三**

根据已有的Drawable创建一个新的Bitmap

public static Bitmap drawableToBitmap(Drawable drawable) {
    
        int w = drawable.getIntrinsicWidth();
        int h = drawable.getIntrinsicHeight();
        System.out.println("Drawable转Bitmap");
        Bitmap.Config config =
                drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
                        : Bitmap.Config.RGB_565;
        Bitmap bitmap = Bitmap.createBitmap(w, h, config);
        //注意，下面三行代码要用到，否则在View或者SurfaceView里的canvas.drawBitmap会看不到图
        Canvas canvas = new Canvas(bitmap);
        drawable.setBounds(0, 0, w, h);
        drawable.draw(canvas);
    
        return bitmap;
    }

# 二、Bitmap 转换成 Drawable #

使用 BitmapDrawable 对 Bitmap 进行强制转换

Drawable drawable = new BitmapDrawable(bmp);

# 三、Bitmap 转换成 byte\[\] #

public static byte[] getBytes(Bitmap bitmap){
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
    
        bitmap.compress(Bitmap.CompressFormat.PNG, 100, baos);
    
        return baos.toByteArray();
     }

# 四、byte\[\] 转化成 Bitmap #

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

[http_blog.csdn.net_l_lhc_article_details_50923372]: http://blog.csdn.net/l_lhc/article/details/50923372